CN105049008A - Signal modulation method and signal rectification and modulation device - Google Patents

Abstract

The invention discloses a signal modulation method and a signal rectification and modulation device for a power receiving module of an inductive power supply. The signal modulation method includes setting a plurality of modulation intervals corresponding to a modulation signal; in The i-th modulation interval among the plurality of modulation intervals modulates the first end of an induction coil of the power receiving module, where i is an odd number; and the j-th modulation interval among the plurality of modulation intervals Modulate the second end of the induction coil of the power receiving module, where j is an even number; wherein, the second end is not modulated when the first end is modulated, and the first end is not modulated when the second end is modulated. .

Description

Signal modulation method and signal rectification and modulation device

technical field

The invention relates to a signal modulation method and a signal rectification and modulation device, in particular to a staggered signal modulation method and a signal rectification and modulation device.

Background technique

In the inductive power supply, in order to operate safely, it is necessary to confirm that the induction area on the power supply coil is the correct power receiving device at the supply end, and only transmit power when the power can be received. In order for the power supply end to identify the power receiving device Whether the terminal is a correct power receiving device needs to be identified by transmitting a data code. The transmission of the data code is to drive the power supply coil to generate resonance through the power supply end, and transmit the electromagnetic energy to the power receiving end for power transmission. When the power receiving end receives power, the impedance state on the receiving coil can be changed through signal modulation technology. Then, the change of the resonant carrier signal on the power supply coil is affected by feedback to transmit the data code.

The above-mentioned data code is composed of a plurality of modulated signals. In the prior art, the receiving end performs signal modulation on both ends of the induction coil at the same time. For example, in the power receiving module 20 of US Patent Publication No. US2013/0342027A1, the power receiving microprocessor 21 simultaneously turns on the switch components A6 and B6 corresponding to both ends of the induction coil, so as to simultaneously modulate both ends of the induction coil. Specifically, during the modulation period, the switch components A6 and B6 are turned on at the same time, so that the signal modulation resistors A3 and B3 are simultaneously modulated. At this time, due to the operation of the control diodes A4 and B4, the lower bridge switch components A2 and B2 are simultaneously turned on. Stop rectification. In this case, if you want to increase the amplitude of the signal reflected to the power supply coil, you need to increase the modulation time. However, the lengthening of the modulation time means that the rectifier stops working for a longer time, which reduces its ability to supply power to the back end. On the other hand, when the resistance values of the signal modulation resistors A3 and B3 are smaller, the signal reflected to the power supply terminal is larger, and at the same time, the power loss during modulation is larger. That is to say, another way to increase the reflected signal is to reduce the signal modulation resistor, but the reduction is still limited by the bottleneck of power loss.

In addition, the lower bridge switch components A2 and B2 used for rectification are respectively connected to the induction coil through the protection resistors B1 and A1, and the gate voltage of the lower bridge switch components A2 and B2 is controlled by the coil voltage to control the lower bridge switch components A2 and B2 are turned on or off to perform rectification operation. However, if the operation speed of the lower switch components A2 and B2 is to be increased, the protection resistors A1 and B1 need to be reduced to increase the gate charging and discharging speed of the lower switch components A2 and B2. In this case, the relatively low resistance protection resistors A1 and B1 will cause the zener diodes A5 and B5 to withstand relatively large power and be easily burned, thus limiting the switching speed of the rectifier switch.

On the other hand, in the power receiving module 20 of the US patent publication US2013/0342027A1, the voltage stabilizing circuit 25 needs a stabilizing capacitor 251 to maintain the stability of the output voltage. An open circuit protection circuit 24 is provided between the piezoelectric capacitor 251 and the rectification and signal feedback circuit 23, so that when the power supply end and the power receiving end induce the initial rectification and signal feedback circuit 23 to start outputting power, the power can be provided to the power receiving microprocessor first. The device 21 is used to prevent the voltage stabilizing capacitor 251 from absorbing too much charge and unable to start the powered microprocessor 21 smoothly. In addition, when the power receiving coil 271 just left the power supply terminal, there is still a large amount of charge in the voltage stabilizing capacitor 251, and this charge will flow back to the power receiving microprocessor 21, so that the power receiving microprocessor 21 cannot judge whether it is currently in the stage of inductive power supply . Furthermore, there may be another problem in the above circuit structure, that is, when the electric power is first sensed, the circuit breaker protection circuit 24 is closed, that is to say, the rectification and signal feedback circuit 23 terminal does not have a large capacitor to assist in absorbing charges. Momentary high voltage may cause damage to circuit components. In addition, when the circuit breaker protection circuit 24 is turned on, the voltage stabilizing capacitor 251 starts to absorb a large amount of charge, which makes the operating voltage of the powered microprocessor 21 drop instantly, which may cause the powered microprocessor 21 to stop operating or produce other adverse effects.

Please refer to FIG. 1 , which is a schematic diagram of a signal modulation waveform. As shown in FIG. 1 , the waveform W1_1 is the gate signal of the switch components A6 and B6 in the power receiving module 20 of US Patent Publication US2013/0342027A1, which turns on the switch components A6 and B6 at the same time at a high potential to generate modulation Signal. The waveform W1_2 represents the signal obtained after the modulation signal is reflected to the power supply end and processed by the signal analysis circuit 13 . From the waveform W1_2, it can be seen that the amount of change of each modulation signal fed back to the power supply terminal is different. This is because in the prior art, the modulation control signal (that is, the gate signal of the switch components A6 and B6) has no relationship with the coil oscillation period. Correspondence. In other words, the modulation signal randomly appears on the oscillation cycle of the power supply coil, so that the starting point and the number of oscillations of the oscillation cycle of the power supply coil reflected in each modulation interval are not fixed, and then the modulation changes the amplitude of the power supply coil. The quantity is not fixed. According to the content of the US patent publication US2013/0342027A1, since the power supply terminal can dynamically adjust the level of the signal discrimination according to the variation of the coil signal, the variation of the coil amplitude with different sizes is likely to cause misjudgment of the signal.

Further, please refer to FIG. 2 , which is a schematic diagram of a signal waveform in a modulation interval of signal modulation. As shown in FIG. 2 , the waveform W2_1 is the gate signal of the switch components A6 and B6 in the power receiving module 20 of the US patent publication US2013/0342027A1, which turns on the switch components A6 and B6 at the same time at a high potential to generate modulation Signal. The waveform W2_2 is the gate voltage of the lower bridge switch component B2. From the above, it can be seen that during modulation, the operation of the control diodes A4 and B4 causes the lower bridge switch components A2 and B2 to stop rectification at the same time, that is, the gate voltage of the lower bridge switch components A2 and B2 should be at zero potential to disconnect the lower bridge switch components A2 and B2. Bridge switch components A2 and B2. However, as shown in the waveform W2_2 of FIG. 2 , during the modulation period (that is, when the gate signals of the switch components A6 and B6 are at a high potential), the gate of the lower bridge switch component B2 still has a residual voltage, which cannot completely reach zero potential. As a result, the lower bridge switch component B2 cannot be completely disconnected, thereby causing redundant power consumption during the modulation process.

As can be seen from the above, there are still many unresolved problems in the prior art. Therefore, it is really necessary to propose a signal modulation method, so that the power receiving module can generate the modulation signal more effectively, and at the same time overcome the above disadvantages.

Contents of the invention

Therefore, the main purpose of the present invention is to provide a signal modulation method and its signal rectification and modulation device to effectively generate modulated signals and solve the above problems.

The invention discloses a signal modulation method, which is used for a power receiving module of an inductive power supply. The signal modulation method includes setting a plurality of modulation intervals corresponding to a modulation signal; modulating a first end of an induction coil of the power receiving module in the i-th modulation interval of the plurality of modulation intervals, wherein i is an odd number; and modulates a second end of the induction coil of the power receiving module in the jth modulation interval of the plurality of modulation intervals, where j is an even number; wherein, when modulating the first end The second end is not modulated, and the first end is not modulated when the second end is modulated.

The invention also discloses a signal modulation method, which is used for a power receiving module of an inductive power supply. The signal modulation method includes setting a plurality of modulation intervals corresponding to a modulation signal; comparing the voltage of a first end or a second end of an induction coil of the power receiving module with a reference voltage to generate a comparison result; and According to the comparison result, the start and stop time points of the plurality of modulation intervals are determined.

The present invention also discloses a signal rectification and modulation device, which is used for a power receiving module of an inductive power supply, and the power receiving module includes an induction coil for receiving power supply. The rectification and modulation device includes a first rectification transistor, a second rectification transistor, a first rectification control module, a second rectification control module, a first modulation control module, a second modulation control module, and a reference voltage generation device, a comparator and a processor. The first rectifying transistor is coupled between a first terminal of the induction coil and a ground terminal, and is used for rectifying the first terminal of the induction coil. The second rectifying transistor is coupled between a second end of the induction coil and the ground end, and is used for rectifying the second end of the induction coil. The first rectification control module is coupled to the first end, the second end and the first rectification transistor of the induction coil, and is used for outputting a first end according to the voltages of the first end and the second end of the induction coil. A rectification control signal for controlling the first rectification transistor to perform rectification. The second rectification control module is coupled to the first end, the second end and the second rectification transistor of the induction coil, and is used for outputting a first end according to the voltage of the first end and the second end of the induction coil. The second rectification control signal is used to control the second rectification transistor to perform rectification. The first modulation control module is coupled to the first end of the induction coil for signal modulation on the first end. The second modulation control module is coupled to the second end of the induction coil for signal modulation on the second end. The reference voltage generator is used to generate a reference voltage. The comparator is coupled to the reference voltage generator and the first rectification control module or the second rectification control module, and is used for comparing the reference voltage and a coil voltage of the induction coil to generate a comparison result. The processor is coupled to the comparator, the first rectification control module, the second rectification control module, the first modulation control module and the second modulation control module, and is used for controlling the first modulation according to the comparison result The control module and the second modulation control module alternately modulate the first end and the second end of the induction coil. Wherein, when the processor controls the first modulation control module to modulate the first end of the induction coil, the second rectification control module disconnects the second rectification transistor to suspend the induction coil. The second end performs rectification, and while controlling the second modulation control module to modulate the second end of the induction coil, the first rectification control module is used to disconnect the first rectification transistor to suspend the induction coil. The first terminal performs rectification.

Description of drawings

Figure 1 is a schematic diagram of a waveform of signal modulation.

FIG. 2 is a schematic diagram of a signal waveform in a modulation interval of signal modulation.

FIG. 3 is a schematic diagram of a power receiving module according to an embodiment of the present invention.

4A and 4B are schematic diagrams of an implementation manner of the modulation control module in FIG. 3 , respectively.

5A and 5B are schematic diagrams of an implementation of the rectification control module in FIG. 3 , respectively.

FIG. 6 is a schematic diagram of signal waveforms when signal modulation is performed in the power receiving module.

FIG. 7 is a schematic diagram of signal waveforms when signal modulation is performed in the power receiving module.

8A and 8B are schematic diagrams of signal waveforms during signal modulation in the power receiving module.

FIG. 9 is a flow chart of a signal modulation process according to Embodiment 1 of the present invention.

Wherein, the reference signs are explained as follows:

W1_1, W1_2, W2_1, W2_2, W6_1, waveform

W6_2, W6_3, W7_1, W7_2, W7_3,

W7_4, W7_5, W7_6, W8_1, W8_2,

W8_3, W8_4, W8_5, W8_6

30 power receiving module

300 induction coil

R1, R2 rectification control module

M1, M2 modulation control module

11, 21 rectifier diode

12, 22 rectifier transistor

121, 221 protection diode

40 voltage regulator

41 voltage stabilizing capacitor

50 power output

60 processors

61 rectifier diode

62 filter capacitor

71 Comparators

72 reference voltage generator

The first end of the S1 induction coil

The second end of the S2 induction coil

S12, S22 rectification control signal

C13, C23 modulation control signal

C14, C24 rectifier off signal

VS coil voltage

Vref reference voltage

CR comparison result

13, 23 modulation transistor

131, 231 modulation load resistance

14, 24 rectification control transistor

141, 143, 241, 243 voltage conversion resistors

142, 144, 242, 244 accelerated discharge diodes

145, 245 protection diodes

146, 246 rectification off transistor

90 signal modulation process

900~916 steps

Detailed ways

Please refer to FIG. 3 , which is a schematic diagram of a power receiving module 30 according to an embodiment of the present invention. The power receiving module 30 can be used in an inductive power supply for receiving power from a corresponding power supply module in the inductive power supply. As shown in Figure 3, the power receiving module 30 includes an induction coil 300, rectifier diodes 11 and 21, rectifier transistors 12 and 22, protection diodes 121 and 221, rectification control modules R1 and R2, modulation control modules M1 and M2, a reference A voltage generator 72 , a comparator 71 , a processor 60 , a voltage regulator 40 and a power output terminal 50 . In addition, in order to provide a stable working voltage for the processor 60 , the power receiving module 30 further includes a rectifier diode 61 and a filter capacitor 62 , which are arranged at the power input end of the processor 60 . In order to provide stable input power to the voltage stabilizer 40 , the power receiving module 30 further includes a voltage stabilizing capacitor 41 with a larger capacitance, which is disposed at the power input end of the voltage stabilizer 40 .

Wherein, the induction coil 300 includes a coil and a capacitor, which can resonate with the coil of the power supply module to generate power and feed back modulation signals and data to the power supply terminal. The rectifier diode 11 is coupled between the first terminal S1 of the induction coil 300 and the power output terminal 50 , and can output power to the power output terminal 50 through the voltage regulator 40 . The rectifier diode 21 is coupled between the second terminal S2 of the induction coil 300 and the power output terminal 50 , and can output power to the power output terminal 50 through the voltage regulator 40 . The rectifier diodes 11 and 21 can respectively output power to the power output terminal 50 in different phases. The rectification transistor 12 is coupled between the first terminal S1 of the induction coil 300 and the ground terminal, and can be used to control the first terminal S1 of the induction coil 300 to perform rectification. The rectification transistor 22 is coupled between the second terminal S2 of the induction coil 300 and the ground, and can be used to control the second terminal S2 of the induction coil 300 to perform rectification. The rectification control module R1 is coupled to the first terminal S1, the second terminal S2 of the induction coil 300 and the rectification transistor 12, and can output a rectification control signal S12 to The rectification transistor 12 is used to control the rectification transistor 12 to perform rectification. The rectification control module R2 is coupled to the first terminal S1, the second terminal S2 of the induction coil 300 and the rectification transistor 22, and can output a rectification control signal S22 to The rectification transistor 22 is used to control the rectification transistor 22 to perform rectification. In this example, the rectifier transistors 12 and 22 are both N-type Metal Oxide Semiconductor Field-Effect Transistors (NMOS), so when the rectifier control signals S12 and S22 are at a high potential, the rectifier transistors 12 and 22 can be turned on. The two ends of the rectifying transistors 12 and 22 can be disconnected when the rectifying control signals S12 and S22 are at low potential.

In detail, when the current of the induction coil 300 is output from the rectifier diode 11, the first terminal S1 of the induction coil 300 is at a high potential, and the second terminal S2 is at a low potential. The potential relationship between the two terminals S2, the rectification control module R2 will conduct the rectification transistor 22, so that the current can flow from the ground terminal to the induction coil 300 to achieve balance; when the current of the induction coil 300 is output from the rectification diode 21, the induction coil 300 The second terminal S2 is at a high potential, and the first terminal S1 is at a low potential. At this time, according to the potential relationship between the first terminal S1 and the second terminal S2 of the induction coil 300, the rectification control module R1 will turn on the rectification transistor 12, so that the current can be Flow from the ground terminal to the induction coil 300 to achieve balance. The protection diodes 121 and 221 are respectively coupled between the gates of the rectifier transistors 12 and 22 and the ground for limiting the gate voltages of the rectifier transistors 12 and 22 within a certain range. That is to say, according to the component characteristics of the rectifying transistors 12 and 22, the protection diodes 121 and 221 can respectively lock the upper limit of the gate voltage of the rectifying transistors 12 and 22, so as to prevent the gate voltages of the rectifying transistors 12 and 22 from exceeding the withstand voltage of the components. And burned. In general, the protection diodes 121 and 221 can be realized by Zener diodes, but should not be limited thereto.

Please continue to refer to Figure 3. The modulation control module M1 is coupled to the first terminal S1 of the induction coil 300 and can be used for signal modulation of the first terminal S1. The modulation control module M2 is coupled to the second terminal S2 of the induction coil 300 and can be used for signal modulation of the second terminal S2. Operations of the modulation control modules M1 and M2 are controlled by the processor 60 . In detail, while controlling the modulation control module M1 to modulate the first end S1 of the induction coil 300, the processor 60 will turn off the rectification transistor 22 through the rectification control module R2 to suspend the modulation of the second end S2 of the induction coil 300. On the other hand, when the processor 60 controls the modulation control module M2 to modulate the second terminal S2 of the induction coil 300, it will disconnect the rectifier transistor 12 through the rectification control module R1 to suspend the first terminal S2 of the induction coil 300 One end S1 is rectified. The reference voltage generator 72 can be used to generate a reference voltage Vref for the comparator 71 . The comparator 71 is coupled to the reference voltage generator 72 and the rectification control module R1 for comparing the reference voltage Vref and a coil voltage VS of the induction coil 300 to generate a comparison result CR and output the comparison result CR to the processor 60 . In detail, the comparator 71 can compare the coil voltage VS of the first end S1 or the second end S2 of the induction coil 300 with the reference voltage Vref to generate a comparison result CR. In the power receiving module 30 of FIG. 3 , an input terminal of the comparator 71 is coupled to the rectification control module R1 to receive the coil voltage VS from the first terminal S1 of the induction coil 300 and compare it with the reference voltage Vref. Compare. In another embodiment, the input terminal of the comparator 71 can also be coupled to the rectification control module R2 to receive the coil voltage VS from the second terminal S2 of the induction coil 300 and compare it with the reference voltage Vref .

In addition, the processor 60 is coupled to the comparator 71, the rectification control modules R1 and R2, and the modulation control modules M1 and M2, and is used to control the modulation control modules M1 and M2 to alternately perform the operation of the induction coil 300 according to the comparison result CR. The signal modulation operation of the first end S1 and the second end S2. In detail, the processor 60 can respectively output the modulation control signals C13 and C23 to respectively control the modulation control modules M1 and M2 to perform modulation at different times. Correspondingly, the processor 60 also respectively outputs rectification off signals C14 and C24 to respectively control the rectification control modules R1 and R2 to suspend rectification during modulation. The processor 60 may be a microprocessor (Microprocessor), a microcontroller (MicroController Unit, MCU) or any type of processing device. In addition, the voltage regulator 40 is controlled by the processor 60 and can be used to receive power from the induction coil 300 . The voltage stabilizing capacitor 41 is coupled between the voltage regulator 40 and the rectifier diodes 11 and 21 for stabilizing the power received by the voltage regulator 40 .

Different from the prior art, where the power receiving module simultaneously modulates signals at both ends of the induction coil, the present invention modulates signals at both ends of the induction coil in a staggered manner. In other words, in the embodiment of the present invention, the processor turns on two modulation control modules alternately to modulate the signals of the first end and the second end of the induction coil respectively in different modulation intervals. The detailed operation method is described as follows .

Please refer to FIG. 4A and FIG. 4B . FIG. 4A and FIG. 4B are schematic diagrams of an implementation manner of the modulation control modules M1 and M2 in FIG. 3 , respectively. As shown in FIG. 4A , the modulation control module M1 includes a modulation transistor 13 and a modulation load resistor 131 . The modulation transistor 13 is controlled by the processor 60 and can be used to modulate the first terminal S1 of the induction coil 300 . The modulation load resistor 131 is coupled between the modulation transistor 13 and the first terminal S1 of the induction coil 300 to provide a load required for modulation. In detail, the processor 60 can output the modulation control signal C13 to the modulation transistor 13 to control the modulation transistor 13 to be turned on or off. When the modulation transistor 13 is turned on, it will change the impedance of the first terminal S1 of the induction coil 300 to the ground terminal, so that the electrical property on the induction coil 300 will change, and the above-mentioned electrical change will be fed back to the power supply terminal, and analyzed through the signal of the power supply terminal And decode and restore the modulated data. In this example, the modulating transistor 13 is an N-type metal oxide semiconductor field effect transistor. When the modulating control signal C13 is at a high potential, the modulating transistor 13 can be turned on, and when the modulating control signal C13 is at a low potential, the modulating transistor 13 can be turned off. . On the other hand, as shown in FIG. 4B , the modulation control module M2 includes a modulation transistor 23 and a modulation load resistor 231 . The modulation transistor 23 is controlled by the processor 60 and can be used to modulate the second terminal S2 of the induction coil 300 . The modulation load resistor 231 is coupled between the modulation transistor 23 and the second terminal S2 of the induction coil 300 to provide a load required for modulation. Similarly, the processor 60 controls the modulation transistor 23 to be turned on or off by modulating the control signal C23 . For the detailed operation method, please refer to the above description related to the modulation control module M1 , which will not be repeated here.

Please refer to FIG. 5A and FIG. 5B . FIG. 5A and FIG. 5B are schematic diagrams of an implementation manner of the rectification control modules R1 and R2 in FIG. 3 , respectively. As shown in FIG. 5A , the rectification control module R1 includes a rectification control transistor 14 , voltage conversion resistors 141 and 143 , accelerating discharge diodes 142 and 144 , a rectification shutdown transistor 146 and a protection diode 145 . The rectification control transistor 14 is an N-type metal-oxide-semiconductor field-effect transistor, and its drain is coupled to the rectification transistor 12 for outputting the rectification control signal S12 to the rectification transistor 12; its source is coupled to the ground; its gate is The voltage conversion resistor 141 and the accelerating discharge diode 142 are connected to the first end S1 of the induction coil 300 to be controlled by the voltage of the first end S1 of the induction coil 300 . When the rectification control transistor 14 is turned on, the rectification control signal S12 can be controlled to reach zero potential to completely turn off the rectification transistor 12 . The voltage conversion resistor 141 is coupled between the first terminal S1 of the induction coil 300 and the gate of the rectification control transistor 14, and can be used to control the gate voltage of the rectification control transistor 14 to vary with the voltage of the first terminal S1 of the induction coil 300. . In addition, the accelerating discharge diode 142 is also coupled between the first terminal S1 of the induction coil 300 and the gate of the rectification control transistor 14, and can be used to control the rectification control transistor 14 when the voltage of the first terminal S1 of the induction coil 300 drops. The gate voltage of the gate voltage drops rapidly, so as to quickly turn off the rectification control transistor 14, and then speed up the improvement of the rectification control signal S12. In other words, the gate voltage of the rectification control transistor 14 can vary with the voltage of the first terminal S1 of the induction coil 300, so as to turn on the rectification control transistor 14 when the voltage of the first terminal S1 of the induction coil 300 rises, and then The rectification transistor 12 is turned off to stop the rectification at the first terminal S1. In addition, the operation of the accelerated discharge diode 142 enables the gate of the rectification control transistor 14 to quickly discharge when the voltage of the first terminal S1 of the induction coil 300 drops, so as to speed up turning off the rectification control transistor 14 . In this way, the turn-on speed of the rectifier transistor 12 can be increased during rectification switching.

Further, the voltage conversion resistor 143 is coupled between the second terminal S2 of the induction coil 300 and the drain of the rectification control transistor 14, and can be used to control the rectification control signal S12 to change with the voltage of the second terminal S2 of the induction coil 300. . In addition, the accelerating discharge diode 144 is coupled between the second terminal S2 of the induction coil 300 and the drain of the rectification control transistor 14, and can be used to accelerate the reduction of the rectification control signal S12 when the voltage of the second terminal S2 of the induction coil 300 drops. voltage. In other words, the rectification control signal S12 can be changed along with the voltage of the second terminal S2 of the induction coil 300 to turn on the rectification transistor 12 when the voltage of the second terminal S2 of the induction coil 300 rises, so as to start the rectification in the induction coil 300. The first end S1 of the rectification. In addition, the operation of the accelerating discharge diode 144 enables the rectification control signal S12 to discharge quickly when the voltage of the second terminal S2 of the induction coil 300 drops. In this way, the turn-off speed of the rectifier transistor 12 can be increased during rectification switching.

Please continue to refer to FIG. 5A. The rectification off transistor 146 is coupled to the processor 60 and the drain of the rectification control transistor 14, and can control the rectification control signal S12 to continuously turn off the rectification transistor 12 when the modulation control module M2 modulates the second terminal S2 of the induction coil 300, The first end S1 of the induction coil 300 is rectified with a pause. In detail, because the signal modulation is to generate a low impedance path to the ground on the induction coil 300, so as to pull the coil signal low when the first terminal S1 or the second terminal S2 of the induction coil 300 is at a high potential, at this time the induction coil The opposite end of the 300 needs to suspend the rectification to avoid the above-mentioned operation of pulling down the coil signal to cause a large amount of current to pass through the rectifier diode and consume too much power. That is, when the second terminal S2 of the induction coil 300 is modulating, the first terminal S1 should suspend rectification; when the first terminal S1 of the induction coil 300 is modulating, the second terminal S2 should suspend rectification. In this case, when the processor 60 turns on the modulation transistor 23 through the modulation control signal C23 to modulate the second terminal S2 of the induction coil 300, it also synchronously turns on the rectification off transistor 146 through the rectification off signal C14, so that the rectifier The control signal S12 drops to zero potential to continuously turn off the rectifying transistor 12 . In addition, the protection diode 145 is coupled between the gate of the rectification control transistor 14 and the ground, and can be used to limit the gate voltage of the rectification control transistor 14 within a certain range. That is to say, according to the component characteristics of the rectification control transistor 14 , the protection diode 145 can lock the upper limit of the gate voltage of the rectification control transistor 14 to prevent the gate voltage of the rectification control transistor 14 from exceeding the withstand voltage of its components and being burned. Generally speaking, the protection diode 145 can be realized by a Zener diode, but should not be limited thereto.

On the other hand, as shown in FIG. 5B , the rectification control module R2 includes a rectification control transistor 24 , voltage conversion resistors 241 and 243 , accelerating discharge diodes 242 and 244 , a rectification shutdown transistor 246 and a protection diode 245 . The rectification control transistor 24 is an N-type metal-oxide-semiconductor field-effect transistor, and its drain is coupled to the rectification transistor 22 for outputting the rectification control signal S22 to the rectification transistor 22; its source is coupled to the ground; its gate is The second end S2 of the induction coil 300 is connected to the second end S2 of the induction coil 300 through the voltage conversion resistor 241 and the acceleration discharge diode 242 to be controlled by the voltage of the second end S2 of the induction coil 300 . The voltage conversion resistor 241 is coupled between the second terminal S2 of the induction coil 300 and the gate of the rectification control transistor 24, and can be used to control the gate voltage of the rectification control transistor 24 to vary with the voltage of the second terminal S2 of the induction coil 300. . In addition, the accelerating discharge diode 242 is also coupled between the second terminal S2 of the induction coil 300 and the gate of the rectification control transistor 24, and can be used to control the rectification control transistor 24 when the voltage of the second terminal S2 of the induction coil 300 drops. The gate voltage of the gate voltage drops rapidly, so as to quickly turn off the rectification control transistor 24, thereby accelerating the improvement of the rectification control signal S22. Further, the voltage conversion resistor 243 is coupled between the first terminal S1 of the induction coil 300 and the drain of the rectification control transistor 24, and can be used to control the rectification control signal S22 to change with the voltage of the first terminal S1 of the induction coil 300. . In addition, the accelerating discharge diode 244 is coupled between the first terminal S1 of the induction coil 300 and the drain of the rectification control transistor 24, and can be used to accelerate the reduction of the rectification control signal S22 when the voltage of the first terminal S1 of the induction coil 300 drops. voltage. The rectification off transistor 246 is coupled to the processor 60 and the drain of the rectification control transistor 24, and can control the rectification control signal S22 to continuously turn off the rectification transistor 22 when the modulation control module M1 modulates the first terminal S1 of the induction coil 300, The second end S2 of the induction coil 300 is rectified with a pause. In this case, when the processor 60 turns on the modulation transistor 13 through the modulation control signal C13 to modulate the first terminal S1 of the induction coil 300, it also synchronously turns on the rectification off transistor 246 through the rectification off signal C24, so that the rectifier The control signal S22 drops to zero potential to continuously turn off the rectifier transistor 22 . In addition, the protection diode 245 is coupled between the gate of the rectification control transistor 24 and the ground, and can be used to limit the gate voltage of the rectification control transistor 24 within a certain range. Regarding the detailed operation mode of the rectification control module R2, reference may be made to the above-mentioned description of the rectification control module R1, which will not be repeated here.

Different from the prior art, the rectification control only controls the rectification transistor by inputting the coil voltage through a single resistor at both ends of the coil. In the embodiment of the present invention, the rectification transistor can be controlled by the rectification control module to improve the rectification switching time. The turn-on and turn-off speed of the rectifier transistor enables the control signal (ie, the gate voltage) of the rectifier transistor to completely reach zero potential when it is turned off, so as to avoid unnecessary power loss caused by the rectifier transistor being unable to be completely turned off during modulation. Please refer to FIG. 6 , which is a schematic diagram of signal waveforms during signal modulation in the power receiving module 30 . As shown in Figure 6, the waveform W6_1 is the modulation control signal C13 output by the processor 60 to the modulation control module M1, which may also represent the rectification shutdown signal C24 output by the processor 60 to the rectification control module R2; the waveform W6_2 is the rectification control module R2 The outputted rectification control signal S22 is the gate signal of the rectification transistor 22; the waveform W6_3 is a waveform that is modulated and fed back to the power supply coil. It can be seen from FIG. 6 that during signal modulation, the signal will be fed back to the power supply coil to produce a change in oscillation amplitude, and compared with the prior art, the rectifier transistor cannot be completely and continuously disconnected during signal modulation (as shown in the waveform of FIG. 2 ). As shown in W2_2), the present invention can completely and continuously turn off the rectifier transistor during signal modulation, so as to avoid additional power loss of the rectifier transistor, thereby improving the modulation efficiency.

It is worth noting that, according to the circuit structure shown in the power receiving module 30 , the present invention can simultaneously achieve fast rectification switching without affecting the current carrying and conduction capability. In detail, according to the characteristics of metal oxide semiconductor field effect transistors, transistors that can be used to withstand large currents often have large parasitic capacitances, which limit the switching speed of gate signals; on the other hand, for gate For a transistor with small parasitic capacitance and high-speed switching capability of its signal, its current-carrying conduction capability must be relatively weak. In this case, the rectifier transistors used in the prior art (such as the lower bridge switch components A2 and B2 in US Patent Publication US2013/0342027A1) must make a trade-off between the current carrying capacity and the rectification switching speed, so that the rectifier ability is limited. In contrast, in the power receiving module 30 of the present invention, the rectifying transistors 12 and 22 can adopt components with strong current-carrying conduction capability to withstand the large current on the induction coil 300 . The rectification switching speed can be improved through the rectification control modules R1 and R2. That is to say, the rectification control transistors 14 and 24 in the rectification control modules R1 and R2 can use transistors with faster switching speeds, and the gates of the rectification control transistors 14 and 24 are connected to each other by accelerating the discharge diodes 142, 144, 242 and 244 respectively. A fast discharge effect is generated at the drain terminal to increase the switching speed of the rectification control signals S12 and S22 , thereby accelerating the switching of the rectification transistors 12 and 22 . In this way, the present invention can simultaneously improve the current carrying capability and the switching speed of rectification.

As mentioned above, the present invention modulates signals at both ends of the induction coil in a staggered manner. Taking the power receiving module 30 as an example, the processor 60 can turn on the modulation control modules M1 and M2 alternately, so as to respectively perform signal modulation on the first terminal S1 and the second terminal S2 of the induction coil 300 in different modulation intervals. In detail, for a modulation signal, the processor 60 can first set a plurality of corresponding modulation intervals. Next, in the ith modulation interval among the above-mentioned multiple modulation intervals, the processor 60 can control the modulation control module M1 to modulate the first end S1 of the induction coil 300, wherein i is an odd number; in the above-mentioned multiple modulation intervals In the jth modulation interval of , the processor 60 can control the modulation control module M2 to modulate the second end S2 of the induction coil 300 , where j is an even number. In other words, in the power receiving module 30 , the second terminal S2 is not modulated when the first terminal S1 of the induction coil 300 is modulated, and the first terminal S1 is not modulated when the second terminal S2 of the induction coil 300 is modulated. Preferably, the number of modulation intervals included in the plurality of modulation intervals is an even number, so that the number of signal modulations performed by the first end S1 and the second end S2 of the induction coil 300 is the same.

In detail, in the above i-th modulation interval, the processor 60 can turn on the modulation transistor 13 coupled to the first terminal S1 of the induction coil 300 through the modulation control signal C13, so as to control the first terminal S1 of the induction coil 300 performing modulation; in the above-mentioned jth modulation interval, the processor 60 can turn on the modulation transistor 23 coupled to the second terminal S2 of the induction coil 300 through the modulation control signal C23, so as to perform modulation on the second terminal S2 of the induction coil 300 modulation. That is, the modulation transistors 13 and 23 are alternately turned on to generate a modulation signal. As mentioned above, when one end of the induction coil 300 is modulating, the opposite end needs to suspend rectification, so as to prevent the rectification circuit from passing a large amount of current and consuming too much power. Since the two ends of the induction coil 300 are modulated in a staggered manner, only one end of the induction coil 300 stops rectification at the same time and the other end can output power normally, which can reduce the impact on the output power of the power supply during signal modulation. . In contrast, the existing technology usually modulates both ends of the induction coil at the same time, so that the rectification at both ends of the coil needs to be suspended at the same time, causing the rectified output voltage to drop sharply instantaneously and affecting the power supply output capability.

Please refer to FIG. 7 , which is a schematic diagram of signal waveforms during signal modulation in the power receiving module 30 . As shown in Figure 7, the waveform W7_1 is the modulation control signal C13 output by the processor 60 to the modulation control module M1, the waveform W7_2 is the modulation control signal C23 output by the processor 60 to the modulation control module M2, and the waveform W7_3 is the coil in the induction coil 300 The signal between the capacitor and the capacitor, the waveform W7_4 is the voltage signal of the first terminal S1 of the induction coil 300, the waveform W7_5 is the rectification control signal S22 output from the rectification control module R2 to the rectifier transistor 22, and the waveform W7_6 is the output of the rectification control module R1 to the rectifier Transistor 12 rectifies control signal S12. In FIG. 7 , a modulation signal corresponds to 4 modulation intervals, wherein only the modulation transistor 13 inside the modulation control module M1 is turned on in the first and third modulation intervals, so as to control the first end of the induction coil 300 S1 performs signal modulation; in the second and fourth modulation intervals, only the modulation transistor 23 inside the modulation control module M2 is turned on, so as to perform signal modulation on the second terminal S2 of the induction coil 300 . Through the above-mentioned signal modulation method, electrical changes can be generated on the coil, which can be fed back to the power supply end and then the modulated data can be recovered through signal analysis and decoding. In addition, when signal modulation is performed, the opposite end of the induction coil 300 will suspend the rectification synchronously. It can be seen from the waveforms W7_5 and W7_6 that through the control of the rectification shutdown transistors 146 and 246, the rectification control signals S12 and S22 can both Completely reach the zero potential to completely and continuously disconnect the rectifier transistors 12 and 22, and the rectification at both ends of the induction coil 300 will not be suspended at the same time, that is, at least one end will rectify and output power at any point in time, so that the signal modulation operation will not affect the power output. Efficiency has too much impact.

It is worth noting that, compared with the existing method of simultaneously modulating signals at both ends of the induction coil, the staggered modulation method of the present invention can also produce obvious signal reflections on the coil at the power supply end, especially when the power supply load is large In the case of , the staggered modulation method of the present invention is less likely to be affected by the load, and can maintain its signal modulation effect.

In addition, in the embodiment of FIG. 7, a modulated signal includes 4 modulation intervals, but in other embodiments, the modulated signal can include any number of modulation intervals, and the length of the modulation interval can also be adjusted according to system requirements. It can be adjusted arbitrarily as long as the lengths of each modulation interval are approximately equal. In addition, in the above-mentioned embodiment, the processor 60 starts the modulation control signal C13 first, and then starts the modulation control signal C23. The control signal C13 is not limited thereto.

On the other hand, through the operation of the comparator and the reference voltage generator, the present invention also solves the disadvantage in the prior art that each modulation signal is fed back to the power supply end with different signal variations. Unlike in the prior art where the modulating signal randomly appears on the oscillation cycle of the coil, in the embodiment of the present invention, the processor can use a comparator to detect the time point at which the potential at both ends of the induction coil The modulation control signal is sent through the switching period (that is, the rectification switching period), so that each modulation signal can correspond to a fixed potential switching period. Please refer to FIG. 3 again, and take the power receiving module 30 in FIG. 3 as an example. The processor 60 can first set a plurality of modulation intervals corresponding to a modulation signal. Next, the comparator 71 compares the coil voltage VS corresponding to the first terminal S1 or the second terminal S2 of the induction coil 300 with the reference voltage Vref to generate a comparison result CR, and outputs the comparison result CR to the processor 60 . The processor 60 then determines the start and stop time points of the above-mentioned multiple modulation intervals according to the comparison result CR. In detail, an input terminal of the comparator 71 can receive the gate voltage of the rectification control transistor 14 in the rectification control module R1 or the rectification control transistor 24 in the rectification control module R2. It can be seen from the circuit structure of the rectification control modules R1 and R2 The gates of the rectification control transistors 14 and 24 are connected to the first terminal S1 and the second terminal S2 of the induction coil 300 through the voltage conversion resistor 141, the accelerating discharge diode 142, the voltage conversion resistor 241 and the accelerating discharge diode 242 respectively, and the gates thereof are The voltage varies with the coil voltage VS of the induction coil 300 . In this case, the gate voltages of the rectification control transistors 14 and 24 may correspond to the coil voltage VS of the induction coil 300 . The other input end of the comparator 71 receives the reference voltage Vref from the reference voltage generator 72 , and outputs a comparison result between the gate voltage and the reference voltage Vref at the output end. The reference voltage Vref should be set at a voltage level between the high potential and the low potential of the gate voltages of the rectification control transistors 14 and 24 to determine the level of the potential at both ends of the induction coil 300 .

It should be noted that the power receiving module 30 only includes a single comparator 71 connected to the rectification control module R1 to receive the gate voltage of the rectification control transistor 14 . Since the switching periods of the first terminal S1 and the second terminal S2 of the induction coil 300 are the same and the potential levels are opposite to each other, the comparator 71 only needs to obtain the period and potential level of the first terminal S1 of the induction coil 300, which is equivalent to Obtain the period and potential level of the second terminal S2. In another embodiment, the comparator 71 can also be changed to be connected to the rectification control module R2 to obtain the period and potential level of the second terminal S2 of the induction coil 300 , but is not limited thereto. In addition, the comparator 71 can also obtain the coil voltage VS and the switching cycle through other methods, not limited to the method of using the rectification control module R1 or R2.

Then, the processor 60 can determine the start and stop time points of each modulation interval according to the comparison result CR (which includes the switching cycle and the potential level of the two ends of the induction coil 300 ). The following example is illustrated with the circuit structure corresponding to the power receiving module 30 in FIG. 3 , that is, the comparator 71 compares the coil voltage VS corresponding to the first terminal S1 of the induction coil 300 with the reference voltage Vref to generate a comparison result CR. Those skilled in the art should be able to deduce the situation that the comparator 71 is connected to the second terminal S2 of the induction coil 300 from the contents disclosed in this example.

First, for a plurality of modulation intervals corresponding to a modulation signal, the processor 60 can set a predetermined time corresponding to each modulation interval. Generally speaking, the predetermined time corresponding to each modulation interval can be set to be the same, It may be approximately equal to a number (eg 3 or 4) of cycles of the coil voltage VS switching. Next, when the processor 60 receives a signal modulation instruction, it can judge the potential level of the first terminal S1 of the induction coil 300 according to the comparison result CR, and accordingly determine whether to start a modulation interval corresponding to the first terminal S1 , and start the timer at the beginning of the modulation interval. When the timing time of the timer reaches the predetermined time (that is, after several cycles), the processor 60 can judge the potential level of the first end S1 of the induction coil 300 according to the comparison result CR, and decide whether to stop modulation interval.

In detail, for the start time of the modulation interval, the processor 60 can judge that the potential of the first terminal S1 of the induction coil 300 drops to a low potential lower than the reference voltage Vref through the comparison result CR after receiving the signal modulation instruction. At this time point, the modulation interval is controlled to start (that is, the modulation transistor 13 in the modulation control module M1 is turned on), so that the first terminal S1 of the induction coil 300 starts to modulate when it is at a low potential. Similarly, for the stop time of the modulation interval, the processor 60 can also judge the time when the potential of the first terminal S1 of the induction coil 300 drops to a low potential lower than the reference voltage Vref through the comparison result CR after the predetermined time arrives. point, and control the modulation interval to stop at this time point (that is, turn off the modulation transistor 13 in the modulation control module M1 ), so that the first terminal S1 of the induction coil 300 stops modulating when it is at a low potential. It should be noted that the operation of signal modulation is to pull down the voltage signals of the first terminal S1 and the second terminal S2 through the modulation transistors 13 and 23 respectively coupled to the first terminal S1 and the second terminal S2 of the induction coil 300 , In this case, since the voltage signals of the first terminal S1 and the second terminal S2 of the induction coil 300 are approximately square waves, the low potential is close to zero potential and cannot produce a pull-down effect, and only the high potential part will be affected by the modulation. In other words, according to the comparison result CR, the processor 60 can control the operation of the signal modulation to start or end when the corresponding coil voltage VS is at a low potential (that is, when it is not affected by the modulation), so that the signal modulation interval can include the complete coil voltage The switching cycle of VS, that is, several complete periods during which the coil voltage VS is at a high potential. Further, since the predetermined time corresponding to each modulation interval is the same, each modulation interval may include the same number of complete switching periods of the coil voltage VS. In this way, each modulating signal can generate a signal variation of the same amplitude on the coil, so as to improve the accuracy of signal discrimination at the power supply end.

On the other hand, the comparison result CR generated by the comparator 71 comparing the voltage of the first terminal S1 of the induction coil 300 with the reference voltage Vref can also be used to determine the potential level of the second terminal S2 of the induction coil 300 . In detail, when the processor 60 receives a signal modulation instruction and intends to modulate the second terminal S2 of the induction coil 300, it can judge the potential level of the first terminal S1 of the induction coil 300 according to the comparison result CR, and then Determine whether the potential of the second terminal S2 of the induction coil 300 is high or low, and accordingly determine whether to start a modulation interval corresponding to the second end S2, and start a timer when the modulation interval starts. When the timing time of the timer reaches the predetermined time (that is, after several cycles), the processor 60 can judge the potential level of the first end S1 of the induction coil 300 according to the comparison result CR, and then judge the first end S1 of the induction coil 300. The potential of the two terminals S2 is high or low, and based on this, it is determined whether to stop the modulation interval. As mentioned above, the first terminal S1 and the second terminal S2 of the induction coil 300 are mutually anti-phase signals, when the first terminal S1 is at a high potential, the second terminal S2 is at a low potential, and when the first terminal S1 is at a low potential, the second terminal S2 The two terminals S2 are at high potential, therefore, only a single comparator 71 is needed to obtain the potential states of the two ends of the induction coil 300 .

In detail, for the start time of the modulation interval, the processor 60 can judge that the potential of the first terminal S1 of the induction coil 300 rises to a high potential higher than the reference voltage Vref through the comparison result CR after receiving the signal modulation instruction. time point, and based on which it is judged that the second terminal S2 of the induction coil 300 is at a low potential, the processor 60 can control the start of the modulation interval at this time point (that is, turn on the modulation transistor 23 in the modulation control module M2), so that the induction The second terminal S2 of the coil 300 starts to modulate when it is at a low potential. Similarly, for the stop time of the modulation interval, the processor 60 can also use the comparison result CR to determine the time point when the potential of the first terminal S1 of the induction coil 300 rises to a high potential higher than the reference voltage Vref after the predetermined time arrives. , and judge accordingly that the second terminal S2 of the induction coil 300 is at a low potential, the processor 60 can control the modulation interval to stop at this time point (that is, disconnect the modulation transistor 23 in the modulation control module M2), so that the induction coil 300 When the second terminal S2 of is at a low potential, the modulation is stopped.

Please refer to FIG. 8A and FIG. 8B . FIG. 8A and FIG. 8B are schematic diagrams of signal waveforms during signal modulation in the power receiving module 30 . FIG. 8A enlarges part of the waveforms in FIG. 7 to clearly show the correspondence between the start and end time points of the modulation interval and the coil voltage VS; FIG. 8B shows the waveforms of multiple modulation signals. As shown in Figure 8A, the waveform W8_1 is an amplification of the waveform W7_4, which represents the voltage signal of the first terminal S1 of the induction coil 300; the waveform W8_2 is the amplification of the waveform W7_1, which represents the modulation control signal C13; the waveform W8_3 represents the comparator 71 The output comparison result CR. It can be seen from FIG. 8A that the start and stop times of the modulation control signal C13 both occur when the voltage of the first terminal S1 of the induction coil 300 is at a low potential, that is, when the corresponding comparison result CR outputs a low potential. Generally speaking, since the switching speed of the coil voltage VS is quite fast, the processing delay of the processor 60 may cause the modulation control signal C13 to be unable to be activated or deactivated exactly at the time when the coil voltage VS is switched to a low potential. However, the modulation control signal C13 As long as the induction coil 300 is turned on or off when the first terminal S1 of the induction coil 300 is at a low potential, the modulation period can be ensured to include a complete switching period of the coil voltage VS, that is, several complete periods when the coil voltage VS is at a high potential. For example, in FIG. 8A , the modulation interval (ie, the time when the modulation control signal C13 turns on the modulation transistor 13 ) includes 4 complete periods in which the coil voltage VS is at a high potential.

In addition, as shown in FIG. 8B, waveforms W8_4 and W8_5 are modulation control signals C13 and C23 respectively, and waveform W8_6 is a signal obtained after the modulation signal generated by the power receiving module 30 is reflected to the power supply end and processed by the signal analysis circuit. . It can be seen from Figure 8B that each modulation signal includes a complete and the same number of coil voltage VS switching cycles, so the signal change amount and change pattern generated on the coil are the same, and reflected to the power supply terminal to obtain the signal waveform through signal analysis Also the same.

It should be noted that the comparator 71 can not only control the time point when the processor 60 performs signal modulation, but also can be used to enable or disable the operation of the processor 60 . In the prior art, the processor decides whether to turn on or not according to whether the power supply voltage it receives reaches the working voltage. Since the voltage stabilizer at the power output terminal of the power receiving module needs to use a voltage stabilizing capacitor, which has a relatively large capacitance value, a switch needs to be set between the voltage stabilizing capacitor and the processor, and the switch needs to be closed before the processor is started. To prevent the induction coil from being connected to the rectified output power to charge the voltage stabilizing capacitor and delay the start-up time of the processor after the required working voltage is increased, or even fail to reach the working voltage and fail to start the processor. For example, the disconnection protection circuit 24 in the power receiving module 20 of US Patent Publication No. US2013/0342027A1 can be used to deal with the above problems. In contrast, in the embodiment of the present invention, the processor 60 may determine whether to turn on or not according to the comparison result CR output by the comparator 71 . In detail, when the power receiving module 30 is close to or placed on a power supply device, the power supply device will first transmit a small amount of power, and the induction coil 300 of the power receiving module 30 will start to resonate after receiving the power, that is, inductive A voltage change is generated at both ends of the coil 300 , and the voltage change can be transmitted to the comparator 71 through the rectification control module R1 or R2 , so as to generate a comparison result CR of continuous switching between high and low potentials. After receiving the comparison result CR, the processor 60 can determine that the power receiving module 30 is located near a power supply device, and start to generate a modulation signal to reflect to the power supply terminal. On the other hand, when the induction coil 300 of the power receiving module 30 leaves the power supply end, the induction coil 300 will immediately stop resonating, even if the charge in the voltage stabilizing capacitor 41 is still enough for the processor 60 to use, the processor 60 can still pass the comparison The device 71 learns that the induction coil 300 has stopped receiving power, and accordingly stops related operations. In this case, since the processor 60 operates according to the comparison result CR, rather than according to the power supply voltage it receives, in the power receiving module 30 of the present invention, the rectifier diodes 11 and 21 can directly output power to The voltage regulator 40 and the power supply output terminal 50 do not need any switch at the front end of the voltage stabilizing capacitor 41 .

In this embodiment, since the power received by the induction coil 300 does not need to pass through the switch, it can be directly transmitted to the voltage regulator 40 and the power output terminal 50 after rectification, so as to avoid power loss caused by the current passing through the switch. In addition, in the prior art, since the voltage stabilizing capacitor is arranged behind the switch, when the switch is turned on, the capacitor will absorb a large amount of power, causing the voltage to drop sharply instantly. If the voltage drops too much, the processor will not be able to operate normally. . In contrast, the embodiment of the present invention does not need to use a switch to isolate the voltage stabilizing capacitor from the processor, so as to avoid the occurrence of the above-mentioned problems.

The above operation of the power receiving module 30 can be summarized into a signal modulation process 90 , as shown in FIG. 9 . The signal modulation process 90 includes the following steps:

Step 900: start.

Step 902: The processor 60 sets a plurality of modulation intervals corresponding to a modulation signal.

Step 904: The processor 60 performs modulation in multiple modulation intervals. If it is the i-th modulation interval (i is an odd number), execute step 906; if it is the j-th modulation interval (j is an even number), execute step 910.

Step 906: The comparator 71 compares the voltage of the first terminal S1 or the second terminal S2 of the induction coil 300 with the reference voltage Vref to generate a comparison result CR, and determine the start and stop times of the i-th modulation interval according to the comparison result CR point.

Step 908: In the i-th modulation interval, the processor 60 turns on the modulation transistor 13 through the modulation control signal C13 to modulate the first terminal S1 of the induction coil 300, and controls the rectification control signal S22 to drop through the rectification off signal C24 Go to zero potential to turn off the rectifier transistor 22 , and then suspend the rectification of the second terminal S2 of the induction coil 300 , and then execute step 914 .

Step 910: The comparator 71 compares the voltage of the first terminal S1 or the second terminal S2 of the induction coil 300 with the reference voltage Vref to generate a comparison result CR, and determine the start and stop times of the jth modulation interval according to the comparison result CR point.

Step 912: In the jth modulation interval, the processor 60 turns on the modulation transistor 23 through the modulation control signal C23 to modulate the second terminal S2 of the induction coil 300, and controls the rectification control signal S12 to drop through the rectification off signal C14 to zero potential to turn off the rectifier transistor 12 , thereby suspending the rectification of the first terminal S1 of the induction coil 300 .

Step 914: The processor 60 determines whether the signal modulation in all the modulation intervals corresponding to the modulation signal is completed. If yes, go to step 916; if not, go to step 904.

Step 916: end.

For the detailed operation and changes of the signal modulation process 90 , reference can be made to the foregoing description, and details are not repeated here.

To sum up, the present invention performs signal modulation through a staggered method, that is, alternately performs signal modulation at the first end and the second end of the induction coil, which can generate obvious signal reflection at the power supply end, and the rectifier located at both ends of the induction coil The transistors do not need to be disconnected at the same time, which can reduce the influence of signal modulation on the output power of the power supply. In addition, through the operation of the comparator, the time point of signal modulation can correspond to the switching cycle of the coil voltage, and the processor can start or stop signal modulation at a specific time point according to the comparison result of the comparator, so that each modulation signal can be online Signal changes of the same amplitude are generated on the circle to improve the accuracy of signal discrimination at the power supply end. In addition, the processor can also use the comparator to determine whether to start operation according to the switching of the coil voltage, rather than the received voltage, so there is no need to set a switch between the voltage stabilizing capacitor and the processor to control the processor working voltage. Furthermore, through the circuit structure of the power receiving module of the present invention, the rectification transistor can be controlled by the rectification control module, so as to simultaneously realize high current carrying capacity and high rectification switching speed.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (27)

1. A signal modulation method for a powered module of an inductive power supply, the signal modulation method comprising: Setting a plurality of modulation intervals corresponding to a modulation signal; modulate the first end of an induction coil of the power receiving module in the i-th modulation interval among the plurality of modulation intervals, where i is an odd number; and modulate the second end of the induction coil of the power receiving module in a jth modulation interval among the plurality of modulation intervals, where j is an even number; Wherein, the second end is not modulated when the first end is modulated, and the first end is not modulated when the second end is modulated. 2. The signal modulation method according to claim 1, further comprising: Turning on a first modulation transistor coupled to the first end of the induction coil to modulate the first end of the induction coil during the ith modulation interval; and In the jth modulation interval, a second modulation transistor coupled to the second end of the induction coil is turned on to modulate the second end of the induction coil. 3. The signal modulation method according to claim 2, wherein the first modulation transistor and the second modulation transistor are turned on alternately to generate the modulation signal. 4. The signal modulation method according to claim 1, wherein the number of modulation intervals included in the plurality of modulation intervals is an even number. 5. The signal modulation method according to claim 1, further comprising: When modulating the second terminal of the induction coil, disconnecting a first rectifier transistor coupled to the first terminal of the induction coil suspends the first end rectification; and disconnecting a second rectifier transistor coupled to the second terminal of the induction coil to suspend modulation of the second terminal of the induction coil while the first terminal of the induction coil is being modulated Perform rectification. 6. The signal modulation method according to claim 1, further comprising: comparing the voltage at the first terminal or the second terminal of the induction coil with a reference voltage to generate a comparison result; and According to the comparison result, the start and stop time points of the plurality of modulation intervals are determined. 7. A signal modulation method for a power receiving module of an inductive power supply, the signal modulation method comprising: Setting a plurality of modulation intervals corresponding to a modulation signal; comparing a voltage at a first end or a second end of an induction coil of the power receiving module with a reference voltage to generate a comparison result; and According to the comparison result, the start and stop time points of the plurality of modulation intervals are determined. 8. The signal modulation method according to claim 7, wherein when comparing the voltage at the first end of the induction coil with the reference voltage, the plurality of modulations are determined according to the comparison result. The steps of the time point of interval start and stop include: setting a predetermined time corresponding to each modulation interval in the plurality of modulation intervals; When receiving a signal modulation instruction, judge the potential level of the first end of the induction coil according to the comparison result, and decide accordingly whether to start corresponding to the first in the plurality of modulation intervals. A modulation interval at the end; at the start of the modulation interval, starting a timer; and When the counting time of the timer reaches the predetermined time, it is judged according to the comparison result whether the potential of the first end of the induction coil is high or low, and accordingly it is determined whether to stop the modulation interval. 9. The signal modulation method according to claim 8, wherein when the signal modulation instruction is received, it is judged according to the comparison result whether the electric potential of the first end of the induction coil is high or low, and The steps for deciding whether to start the modulation interval accordingly include: judging a time point at which the potential of the first end of the induction coil drops to a low potential lower than the reference voltage based on the comparison result; and The start of the modulation interval is controlled at the time point, so that the first end of the induction coil starts to modulate when it is at the low potential. 10. The signal modulation method according to claim 8, wherein when the counting time of the timer reaches the predetermined time, it is judged according to the comparison result that the first end of the induction coil is located The potential level of , and the steps of deciding whether to stop the modulation interval accordingly include: judging a time point at which the potential of the first end of the induction coil drops to a low potential lower than the reference voltage based on the comparison result; and The modulation interval is controlled to stop at the time point, so that the first end of the induction coil stops modulating when it is at the low potential. 11. The signal modulation method according to claim 7, wherein when comparing the voltage at the first end of the induction coil with the reference voltage, the plurality of modulations are determined according to the comparison result. The steps of the time point of interval start and stop include: setting a predetermined time corresponding to each modulation interval in the plurality of modulation intervals; When receiving a signal modulation instruction, judge the potential level of the first end of the induction coil according to the comparison result, and then judge the potential level of the second end of the induction coil, and Based on this, it is determined whether to start a modulation interval corresponding to the second end among the plurality of modulation intervals; at the start of the modulation interval, starting a timer; and When the counting time of the timer reaches the predetermined time, judge the potential level of the first end of the induction coil according to the comparison result, and then judge the electric potential of the second end of the induction coil The potential at the location is high or low, and based on this, it is decided whether to stop the modulation interval. 12. The signal modulation method according to claim 11, wherein when the signal modulation instruction is received, it is judged according to the comparison result whether the electric potential of the first end of the induction coil is high or low, and then The step of judging the potential level of the second end of the induction coil and deciding whether to start the modulation interval accordingly includes: judging a time point when the potential of the first end of the induction coil rises to a high potential higher than the reference voltage according to the comparison result; When the first end of the induction coil is at the high potential, determine that the second end of the induction coil is at a low potential; and The start of the modulation interval is controlled at the time point, so that the second end of the induction coil starts to modulate when it is at the low potential. 13. The signal modulation method according to claim 11, characterized in that, when the counting time of the timer reaches the predetermined time, it is judged according to the comparison result that the first end of the induction coil is located The potential level of the induction coil, and then judge the potential level of the second end of the induction coil, and the step of deciding whether to stop the modulation interval accordingly includes: judging a time point when the potential of the first end of the induction coil rises to a high potential higher than the reference voltage according to the comparison result; When the first end of the induction coil is at the high potential, determine that the second end of the induction coil is at a low potential; and The modulation interval is controlled to stop at the time point, so that the second end of the induction coil stops modulating when it is at the low potential. 14. A signal rectification and modulation device for a power receiving module of an inductive power supply, the power receiving module includes an induction coil for receiving power from a power supply module of the inductive power supply , the rectification and modulation device includes: a first rectification transistor, coupled between the first terminal of the induction coil and the ground terminal, and used to control the first terminal of the induction coil to perform rectification; a second rectification transistor, coupled between the second terminal of the induction coil and the ground terminal, and used to control the second terminal of the induction coil to perform rectification; A first rectification control module, coupled to the first end of the induction coil, the second end and the first rectification transistor, for output a first rectification control signal to control the first rectification transistor to perform rectification; A second rectification control module, coupled to the first end of the induction coil, the second end and the second rectification transistor, for output a second rectification control signal to control the second rectification transistor to perform rectification; a first modulation control module, coupled to the first end of the induction coil, and used for signal modulation on the first end; a second modulation control module, coupled to the second end of the induction coil, and used for signal modulation on the second end; a reference voltage generator, used to generate a reference voltage; a comparator, coupled to the reference voltage generator and the first rectification control module or the second rectification control module, for comparing the reference voltage with the coil voltage of the induction coil to generate a comparison result; and A processor, coupled to the comparator, the first rectification control module, the second rectification control module, the first modulation control module, and the second modulation control module, for according to the comparison As a result, controlling the first modulation control module and the second modulation control module to alternately perform modulation at the first end and the second end of the induction coil; Wherein, when the processor controls the first modulation control module to modulate the first end of the induction coil, it also disconnects the second rectification transistor through the second rectification control module to suspend Rectifying the second end of the induction coil, and while controlling the second modulation control module to modulate the second end of the induction coil, disconnecting the second end of the induction coil through the first rectification control module the first rectifying transistor to suspend rectifying the first end of the induction coil. 15. The signal rectification and modulation device according to claim 14, further comprising: a first rectifier diode, coupled between the first end of the induction coil and a power output end, for outputting power to the power output end; and A second rectifier diode, coupled between the second end of the induction coil and the output end of the power supply, for outputting power to the output end of the power supply. 16. The signal rectification and modulation device according to claim 15, wherein the power receiving module further comprises: a voltage regulator, controlled by the processor, for receiving power from the induction coil; and a stabilizing capacitor, coupled between the voltage regulator, the first rectifier diode, and the second rectifier diode, for stabilizing the power received by the voltage regulator; Wherein, no switch is included between the first rectifier diode, the second rectifier diode and the voltage stabilizing capacitor. 17. The signal rectification and modulation device according to claim 14, further comprising: a first protection diode, coupled between the gate of the first rectifying transistor and the ground terminal, and used to limit the gate voltage of the first rectifying transistor within a certain range; and A second protection diode, coupled between the gate of the second rectifying transistor and the ground terminal, is used to limit the gate voltage of the second rectifying transistor within a certain range. 18. The signal rectification and modulation device according to claim 14, wherein the first rectification control module comprises: A rectification control transistor is used to control the first rectification control signal to reach zero potential when it is turned on, and the rectification control transistor includes: a drain coupled to the first rectifier transistor; a source coupled to the ground; and a gate; a first voltage conversion resistor, coupled between the second end of the induction coil and the drain of the rectification control transistor, for controlling the first rectification control signal to follow the induction coil The voltage change of the second terminal; a first accelerating discharge diode, coupled between the second end of the induction coil and the drain of the rectification control transistor, when the voltage at the second end of the induction coil drops, to accelerate the reduction of the first rectification control signal; a second voltage conversion resistor, coupled between the first terminal of the induction coil and the gate of the rectification control transistor, for controlling the gate voltage of the rectification control transistor to follow the a voltage change at the first end of the induction coil; a second accelerating discharge diode, coupled between the first end of the induction coil and the gate of the rectification control transistor, when the voltage at the first end of the induction coil drops, The gate voltage used to control the rectification control transistor drops rapidly, so as to quickly turn off the rectification control transistor, thereby accelerating the increase of the first rectification control signal; a rectification off transistor, coupled to the processor and the drain of the rectification control transistor, when the second modulation control module modulates the second terminal of the induction coil, controls the a first rectification control signal turns off the first rectification transistor to suspend rectification on the first end of the induction coil; and A protection diode, coupled between the gate of the rectification control transistor and the ground terminal, is used to limit the gate voltage of the rectification control transistor within a certain range. 19. The signal rectification and modulation device according to claim 14, wherein the second rectification control module comprises: A rectification control transistor is used to control the second rectification control signal to reach zero potential when turned on, and the rectification control transistor includes: a drain coupled to the second rectifying transistor; a source coupled to the ground; and a gate; a first voltage conversion resistor, coupled between the first terminal of the induction coil and the drain of the rectification control transistor, and used to control the second rectification control signal to follow the induction coil The voltage change of the first terminal; a first accelerating discharge diode, coupled between the first end of the induction coil and the drain of the rectification control transistor, when the voltage at the first end of the induction coil drops, Used to accelerate the reduction of the second rectification control signal; a second voltage conversion resistor, coupled between the second terminal of the induction coil and the gate of the rectification control transistor, for controlling the gate voltage of the rectification control transistor to follow the a voltage change at the second end of the induction coil; a second accelerating discharge diode, coupled between the second end of the induction coil and the gate of the rectification control transistor, when the voltage at the second end of the induction coil drops, controlling the gate voltage of the rectification control transistor to drop rapidly, so as to quickly disconnect the rectification control transistor, thereby accelerating the increase of the second rectification control signal; a rectification off transistor, coupled to the processor and the drain of the rectification control transistor, when the first modulation control module modulates the first end of the induction coil, controls the a second rectification control signal turns off the second rectification transistor to suspend rectification of the second terminal of the induction coil; and A protection diode, coupled between the gate of the rectification control transistor and the ground terminal, is used to limit the gate voltage of the rectification control transistor within a certain range. 20. The signal rectification and modulation device according to claim 18 or 19, characterized in that the current-carrying conduction capability of the rectification control transistor is smaller than that of the first rectification transistor and the second rectification transistor, and the switching speed larger than the first rectifying transistor and the second rectifying transistor. 21. The signal rectification and modulation device according to claim 14, wherein the first modulation control module comprises: a modulation transistor, controlled by the processor, for modulating the first end of the induction coil; and A modulating load resistor is coupled between the modulating transistor and the first end of the induction coil to provide a modulating load. 22. The signal rectification and modulation device according to claim 14, wherein the second modulation control module comprises: a modulation transistor, controlled by the processor, for modulating the second end of the induction coil; and A modulating load resistor is coupled between the modulating transistor and the second end of the induction coil to provide a modulating load. 23. The signal rectification and modulation device according to claim 14, wherein the comparator comprises: A first input end, used to receive a gate voltage of a rectification control transistor of the first rectification control module or the second rectification control module, wherein the gate voltage corresponds to the voltage of the induction coil coil voltage; a second input terminal for receiving the reference voltage; and An output terminal is used for outputting the comparison result to the processor according to the magnitude of the gate voltage and the reference voltage. 24. The signal rectification and modulation device according to claim 14, wherein the processor performs the following steps to modulate the signal: Setting a plurality of modulation intervals corresponding to a modulation signal; controlling the first modulation control module to modulate the first end of the induction coil in the i-th modulation interval among the plurality of modulation intervals, where i is an odd number; and controlling the second modulation control module to modulate the second end of the induction coil in the jth modulation interval among the plurality of modulation intervals, where j is an even number; Wherein, the second end is not modulated when the first end is modulated, and the first end is not modulated when the second end is modulated. 25. The signal rectification and modulation device according to claim 24, wherein the processor alternately turns on a modulation transistor located in the first modulation control module and the second modulation control module to generate the the modulation signal. 26. The signal rectification and modulation device as claimed in claim 24, wherein the processor also performs the following steps to perform signal modulation: According to the comparison result, the start and stop time points of the plurality of modulation intervals are determined. 27. The signal rectification and modulation device according to claim 14, wherein the processor determines whether to be turned on according to the comparison result output by the comparator.