TW200847614A - Constant current and constant voltage driving circuit of low acoustic noise and speed controllable DCBL fan motor - Google Patents

Abstract

A constant current and constant voltage driving circuit of a DC motor is used for driving a first magnetic coil and a second magnetic coil included in the DC motor. The driving circuit includes an integrated circuit (IC) chip, a first switch, a second switch. The integrated circuit chip generates currents to drive the first switch and the second switch by using the constant-current driving method. The first switch and the second switch amplify the generated currents by using the constant-voltage driving method, to drive the first magnetic coil and the second magnetic coil, respectively. Furthermore, the driving circuit can also include a control circuit, and control the first magnetic coil and the second magnetic coil with pulse width modulation signals to obtain the desired rotation frequency of the DC motor.

Description

200847614 IX. Description of the Invention: [Technical Field] The present invention relates to a driving circuit for a DC motor, and particularly relates to a combination of a constant current and a constant voltage for driving a DC brushless (1) C Brushless, DCBL) The drive circuit of the wind motor. [Prior Art]

Traditionally, the use of DC brushless fans has been mainly for the heat dissipation of various electronic products. Because when the amount of sputum is accumulated in the meat field of the production, and the inside of the mouth of the scorpion is accumulated and cannot be dissipated, the various readings will not be able to function properly, and even the entire system may be damaged or the components may be damaged. Therefore, the use of a DC motor fan as a means of heat transfer enables various components of the system to operate in a preferred temperature environment. The general drive DC fan motor is a driving method that uses a constant voltage output. Referring to Fig. 1A, a conventionally driven circuit using a constant voltage output is shown. The driving circuit 1〇〇 includes two transistors M1 and M2, and two transistors

Ml and M2 are respectively an NPN type bipolar junction transistor (Bip〇h

Junction Transist〇r, BJT), and its collector-to-emitter voltages are respectively Vce2, which is the voltage of the two output points DO and DOB in Figure 1. The voltages of the two output points DO and DOB are respectively used to drive the two magnetic coils L1 and L2 of the power supply magnetic field in the DC fan motor, wherein the impedances of the two magnetic coils L1 and = are Z1 and Z2, respectively. In addition, the supply voltage and the total supply current are VCC and ICC, respectively, and the currents flowing through the two magnetic coils li and L2 are II and 12, respectively. When driven at a constant voltage, the two transistors M1 and M2 are controlled by two control voltages k and VI, and are turned on at different times. When the transistor is off 6 200847614, the transistor will go into the cutoff region, where the current through the transistor is very small and close to zero, so the output point voltage is approximately equal to VCC. When the transistor is turned on, the current of the transistor will gradually increase and enter the saturation region, and the saturation voltage of the collector to the emitter is Vcei, sat and Vce2, sat' and is almost fixed. . At this time VCC = VCel, sat + Π * Ζ 1 = VCe2, cutoff + I2 * Z2 or VCC = Vce2 'sat + I2 * Z2 = vcel, cut0ff + n * zi , where Z1 and Z2 are composed of two magnetic coils LI and L2 The coil resistance and the fan motor rotation frequency are determined. However, the method of driving with a 疋 voltage is more suitable for the case of a large current. If the constant voltage drive is still used in the low drive current motor, the magnetic coil L1 (the same as the magnetic coil L2), because the vcel remains fixed and the coil resistance is a large value, a small change in the power supply VCC will result in The low current II varies greatly in proportion, making the motor speed change and unstable. Therefore, this driving method is not suitable for applications with low speed and low current motors. On the other hand, when the transistor M1 (or the transistor M2) performs the switching operation of turning on and off in a constant voltage driving manner, it is induced on the magnetic coil L1 (or the magnetic coil L2) due to the change of the magnetic field. A counter electromotive force, and this back electromotive force causes considerable noise in the magnetic coil and the entire fan motor. Referring to Figure 1B, the measurement waveforms of the DC voltage source and the output voltages of the output terminals DO and DOB are shown. As can be seen from the figure, when the transistors M1 and M2 are switched, the output voltages of the output terminals D〇 and D〇B are instantaneously generated by the counter electromotive force, and for the measured straight 7 200847614 power supply VCC It also causes power supply noise. Please refer to the 1C figure, the system does not output the endpoint 00 and! ) The measured waveform of the output voltage of 〇3 and its corresponding spectrogram. As can be seen from the figure, due to the influence of noise at the output end point and the generated back electromotive force and power supply noise, there are many odd multiples f and even multiple frequencies in addition to (4) (application). And the odd-numbered frequency and the even-numbered frequency converge slowly, causing major noise interference. A conventional method for solving the above problems proposes a constant current driving method which can be applied to a low-speed, low-current motor and can reduce the noise caused by the fan motor. Referring to Fig. 2, a conventional driving circuit using a constant current output is shown. The driving circuit 2 includes two transistors M), M4, and one end is connected to a first reference voltage vss, wherein the two transistors M3 and M4 are also an NPN bipolar junction transistor (bjt). And its collector-to-emitter voltages are 13 and U, respectively, that is, the voltages of the two output points DO and DOB in FIG. The voltages of the two output points D〇 and D〇B respectively drive the two magnetic coils and L4 which provide electromagnetic fields in the DC fan motor, wherein the impedances of the two magnetic coils L3 and L4 are Z3 and Z4, respectively. In addition, the supply voltage is VCC, and the currents flowing through the two magnetic coils L3 and L4 are 13 and 14, respectively. The two transistors M3 and M4 are controlled by two control voltage signals V3 and V4 and are turned on at different times. When the transistor M3 is turned on, the transistor M3 operates in the active region regi〇n according to the control voltage signal Tiger V3, so the current 13 flowing through the magnetic coil L3 tends to a fixed value and remains unchanged. Similarly, when the transistor M4 is turned on, the transistor %4 is in the active region according to the control voltage signal V4, so the current 14 flowing through the magnetic line 8 200847614 circle L4 also tends to a fixed value and remains unchanged. . At this time VCC = Vce3, active + I3*Z3 = Vce4, cutoff + I4*Z4, and 14 = 0 or VCC = Vce4, active + I4*Z4 = Vce3, cutoff + I3*Z3, and 13 = 0, where 13 and 14 are fixed values, which can be determined by the design specifications of the constant current, and • z3 and z4 are also determined by the coil resistance of the two magnetic coils L3 and L4 and the rotational frequency of the fan motor. As a result, the transistors M3 and M4 are respectively controlled as a constant current source, and a current source is generated during the period in which the transistor is turned on, thereby providing a constant current. The constant current drive can solve some problems caused by constant voltage drive. However, since its operating current is usually not considered to be increased under the consideration of heat dissipation, it cannot be applied to a high-speed fan motor. Therefore, a drive is required. The circuit can simultaneously reduce the noise generated by the fan motor and is suitable for the application of the high-speed, high-current fan motor. SUMMARY OF THE INVENTION According to the present invention, a constant current constant voltage driving circuit for a DC motor is proposed. The DC motor includes a first magnetic coil and a second magnetic coil, wherein the first magnetic coil has a first end point and a second end point, and the second magnetic coil has a third end point and a fourth end point, and the second end point The point and the fourth end are electrically coupled to a first reference voltage. The driving circuit comprises an integrated circuit crystal switch and a second switch. The integrated circuit chip has a first The outer day chip output end and the second chip sixth end point, wherein the first (four) one brother five end points and the - chip transfer w ~ 1 electricity (four) are connected to the integrated circuit chip The second switch is electrically coupled to the second reference voltage, and the sixth end is electrically coupled to the first end of the first magnetic coil. The second switch has a second control end, a seventh end point and an eighth end point, wherein the second control end is electrically coupled to the second wafer wheel output end of the integrated circuit chip, and the seventh end end is electrically coupled to the second reference voltage, the eighth end The first switch and the second open relationship are respectively connected to the first current of the first chip output end and the second chip output end and a second current according to the third end point of the second magnetic coil. The current is turned on at different times to drive the first magnetic coil to a magnetic coil, wherein the first current or the second current is substantially constant, and the first magnetic coil and the second magnetic coil are respectively at different times. Driving according to a certain voltage generated by each of the first switch and the second switch. According to the embodiment of the present invention, the driving circuit using the DC motor can simultaneously include constant current driving and constant voltage driving. In order to reduce the noise generated by the motor, it is suitable for the application of a high-speed, high-current motor. [Embodiment] Referring to Figure 3, a DC motor drive according to a first embodiment of the present invention is illustrated. A schematic diagram of the circuit. The DC motor includes two magnetic coils li and L2, and each of the two magnetic coils LaL2 has one end electrically connected to a first reference voltage. In the present embodiment, the first reference voltage is a ground GND. The driving circuit 300 includes an integrated circuit (IC) chip 3〇2 and two switches Q1 and Q2'. In this example, the switches Q1 and Q2 are respectively a type of bipolar junction transistor (8) τ). The system uses a four-pin (pin) 200847614 single-in-line package (SIP), and its four pins are respectively coupled to the end of the second reference voltage VCC, the chip output terminals DO and DOB. And the end point of the grounding terminal GND is coupled, and in the embodiment, the second reference voltage VCC is a high DC voltage. The control terminal of the transistor Q1, that is, the base terminal, is electrically coupled to the chip output terminal DO of the 1C chip 302. The emitter is electrically coupled to the high DC voltage VCC, and the collector is electrically coupled to the magnetic coil. The other end of L1. The control terminal of the transistor Q2, that is, the base terminal, is electrically coupled to the chip output terminal DOB of the 1C chip 302. The emitter is electrically coupled to the high DC voltage VCC, and the collector is electrically coupled to the magnetic coil. The other end of L2. Wherein, when the 1C chip 302 is in operation, the wafer output terminals DO and DOB generate corresponding operating currents IC1 and IC2 at different times, and the transistor Q1 and the transistor Q 2 flow through the wafer output terminals D Ο and D Ο B, respectively. The currents IC1 and IC2, the magnetic field sensing, and the control state are turned on at different times to drive the two magnetic coils L1 and L2, respectively. The two magnetic coils L1 and L2 are driven at different times according to respective voltages generated by the respective transistors Q1 and Q2. Among them, the current IC1 or IC2 is substantially constant and flows to the wafer output terminals DO and DOB, respectively. In addition, the driving circuit 300 further includes two resistors R1 and R2 and two capacitors C1 and C2, wherein the resistor R1 is electrically coupled between the control terminal of the transistor Q1 and the chip output terminal DO of the 1C chip 302, and the resistor R2 is electrically connected. It is coupled between the control terminal of the transistor Q2 and the wafer output terminal DOB of the 1C wafer 302. The two resistors R1 and R2 are used to reduce the voltage at the output terminals DO and DOB, respectively, i.e., to reduce the operating power of the 1C wafer 302, thereby reducing the operating temperature of the 1C wafer 302 during operation. In addition, the two resistors 11 200847614 R1 and R2 must be used such that the transistors q and q2 operate in the saturation region, respectively, and ensure that the operating temperatures of the transistors Q1 and Q2 are not overheated. The two valleys C1 and C2 are electrically coupled to one ends of the magnetic coils L1 and L2 and the collector terminals of the transistors Q1 and Q2, respectively, for further reducing the spur caused by the counter electromotive force. Referring to Figure 4, there is shown a schematic diagram of a drive circuit of a DC motor in accordance with a second embodiment of the present invention. The DC motor includes two magnetic coils L1, and L2, and two magnetic coils, ^1, and 12, each having one end electrically coupled to the high DC voltage VCC. The driver circuit 300a includes a 1C chip 303 and two switches Q1' and Q2', and in this example, the switches Qi, and q2 are each an NpN type bipolar junction transistor (BJT). The control terminal of the transistor Q1, that is, the base terminal, is electrically coupled to the chip output terminal DO of the 1C chip 303, and the emitter is electrically coupled to the ground GND, and the collector is electrically coupled to the magnetic coil. L1, the other end. The control terminal of the transistor Q2, that is, the base terminal, is electrically coupled to the chip output terminal DOB of the 1C chip 303, and the emitter is electrically coupled to the ground GND, and the collector is electrically coupled to the magnetic coil. The other end of L2. Similarly, when the 1C wafer 303 is in operation, the wafer output terminal d〇*d〇b will generate corresponding operating currents Ici, Ic2, and the transistor Q1' and the transistor Q2, respectively, flowing through the wafer wheel. The currents IC1' and Ια' of the terminals D〇 and d〇b, the magnetic field sensing and the control state are turned on at different times, thereby driving the two magnetic coils L1, and L2, respectively. The two magnetic coils li, and L2 are driven at different times according to the transistor Q1 and a certain voltage generated by the respective transistors. Wherein, the current, or Ic2, is substantially a threshold and is output from the output and output of the chip, respectively. In addition, the driving circuit 300a may also include two resistors R1, and R2, and 12 200847614 two electric switches Cl and C2, wherein the resistor R1 is electrically connected to the control of the transistor, and the chip output of the 1C chip 303. Between the terminals D, the resistance is electrically connected between the control terminal of the transistor Q2 and the wafer wheel end DOB of the IC chip 3〇3. * Resistors R1, and R2 are used to reduce the power of the wafer output terminals DO and DOB, respectively, that is, to reduce the operating power of the lc wafer, thereby reducing the operating temperature of the IC wafer 303 during operation. In addition, the two resistors R1, and R2 must be used to make the transistor Q1, and operate separately, and ensure that the operating temperatures of the transistors Q1, and Q2 are not overheated. The two capacitors C1' and C2' are respectively connected to the ends of the magnetic coils u, and L2, to further reduce the spur caused by the counter electromotive force. Referring to Fig. 5, there is shown a block diagram of the circuit inside the integrated circuit chip in Fig. 3. The integrated circuit (IC) chip 3〇2 includes a magnetic sensing element 500, a control circuit 5〇2, and a driving circuit 5〇4. Magnetic sensing Several pieces of the 500 series are used to detect changes in the magnetic field generated when the DC motor rotates.

And by which a sensing signal is output. The control circuit 5〇2 is electrically coupled to the magnetic sensing element 500 and receives the sensing signal output by the magnetic sensing element 5〇〇 to output a corresponding control signal. The driving circuit 5〇4 is electrically coupled to the control circuit 502 and receives the control signal outputted by the control circuit 5〇2, thereby outputting the corresponding driving signal through the output terminals DO and DOB. U. Referring to FIG. 6, a schematic diagram showing the connection between the internal driving circuit of the 1C chip and the external circuit in FIG. 3 includes two switches Q〇〇 and Qdob, and a constant current source for supplying a certain current. . In this embodiment, the switches Qdo and Qdob are respectively an NPN-type bipolar junction transistor, and the constant current source can be realized by an NPN-type bipolar junction transistor (^^. The transistor 卩(10) and Qdob The control terminal 'ie, the base terminal' receives the control signals 13 200847614 and the voltage signals V〇〇 and V〇ob ', respectively, and the collector terminals of the transistors Qdo and Qdob serve as the chip outputs DO and DOB of the 1C wafer 302, respectively. The control terminal, the base terminal, is biased via another NPN-type bipolar junction transistor Qb such that the transistor Qa operates in the active 'region and provides a certain current; the transistor Qa The extremes of the electrical interface are connected to the emitters of the transistors Qdo and Qdob, and the emitters of the transistors Qa are electrically coupled to the ground GND via a resistor Ra. When the transistor Qa is turned on, the transistor Qa will work in the active region, and the current I flowing through the collector's extreme will stay close to a fixed value and remain unchanged. The two transistors Qdo and Qdob are controlled by two control voltage signals Vdo and Vdob, respectively. Turn on at different times. When the transistor Qdo is turned on, The crystal Qdo will operate in the active region according to the control voltage signal Vdo. The current IC1 flowing through the transistor Qdo will tend to be constant and remain unchanged. Similarly, when the transistor Qdob is turned on, the transistor Qdob will be controlled according to the control. The voltage signal Vdob is in the active region. The current Ic2 flowing through the transistor Qdob also tends to a constant value and remains unchanged. t When the transistor Qdo is turned on by the control voltage signal VD0, the transistor Q1 is also turned on. It will therefore be turned on and operate in the saturation region, so that the current IC1 generated by the collector terminal of the transistor QDO can be amplified by the transistor Q1 and generate a correspondingly large voltage at the output terminal DO' to drive The magnetic coil L1 operates. Similarly, when the transistor QDOB is turned on by the control of the control voltage signal VD0B, the transistor Q2 is also turned on and operates in the saturation region, so that the set terminal of the transistor Qdob is made. The generated current IC2 can be amplified by the transistor Q2, and a correspondingly large voltage is generated at the output terminal DOB' to drive the magnetic coil L2 to operate. 14 200847614 Please refer to FIG. A schematic diagram of a driving circuit of a DC motor according to a third embodiment of the present invention. The driving circuit 300b further includes resistors R3 and R4. The ends of the resistors R3 and R4 are respectively Electrically coupled to the magnetic coils L1 and L2 and the collector terminals of the transistors qi and Q2, and the other end is electrically coupled to the capacitors C1 and C2, respectively, to avoid the momentary large current affecting the action of the magnetic coils L1 and L2 .

Referring to Fig. 8, there is shown a schematic diagram of a driving circuit for a DC motor according to a fourth embodiment of the present invention, including a rotational frequency detecting signal generating circuit. Compared with FIG. 3, the driving circuit 3〇〇c may further include a switch Q3 and a resistor R5, and in this example, the switch Q3 is an NPN type bipolar junction transistor. The control terminal of the transistor Q3, that is, the base terminal, is electrically coupled to the collector terminal of the transistor Q2 via the resistor R5 and the magnetic coil B2, and the emitter terminal of the electrical aa body Q3 is electrically connected to the ground terminal, and the electricity is connected. The collector terminal of the crystal Q3 is used for outputting a voltage detection signal, wherein the voltage detection signal is a motor speed frequency detection signal FG (Frequency Generation) for the control system to perform the rotation frequency of the DC fan motor. _. In this embodiment, the transistor Q3 outputs a motor speed frequency detection signal according to the voltage of the output terminal B, the tiger. In another example, the transistor Q3 outputs a motor switching frequency detection signal FG according to the voltage signal of the output terminal DO. Erxiang..., Figure 9 is a measurement waveform diagram of the output terminal DO, and DOB, pressure and speed frequency detection signals in Figure 8. In Figure 8, when the transistor Q2 is turned on and off according to the Ic chip 3〇2, the daytime transistor Q3 will perform the corresponding turn-on according to the continuous high and low switching voltage generated by the transistor Q2. Closed, so that the collector output voltage of the transistor Q3 200847614 can generate a corresponding high and low conversion voltage when coupled to a load to a high potential, and form a motor speed frequency detection signal FG that can be detected. Referring to FIG. 10, A schematic diagram of a driving circuit for a direct current motor including a rotational frequency detecting signal generating circuit according to a fifth embodiment of the present invention is shown. The driving circuit 300d can also include a resistor as compared with FIG. R3 and R4. One ends of the resistors R3 and R4 are electrically coupled to the magnetic coils L1 and L2 and the collector terminals of the transistors Q1 and Q2, respectively, and the other end is electrically coupled to the capacitors C1 and C2, respectively. The instantaneous high current affects the operation of the magnetic coils L1 and L2. Referring to Fig. 11, there is shown a schematic diagram of a drive circuit including a PWM control circuit for a DC motor according to a sixth embodiment of the present invention. In other words, the driving circuit 300e further includes a switch Q4, and in this example, the switch Q4 is a PNP type bipolar junction transistor. The control terminal of the transistor Q4, that is, the base terminal, is used to receive a pulse width modulation. The Pulse Width Modulation signal PWM1 is electrically coupled to the high DC voltage VCC, and the collector is electrically coupled to the base terminal of the transistor Q1 and electrically coupled to the 1C via the resistor R1. The wafer output terminal DO of the wafer 302. When the transistor Q4 operates in the saturation region, regardless of whether or not the wafer output terminal DO has a current switching action, the transistor Q1 operates in a cut-off and flows through the magnetic coil. The current of L1 is 0. When the transistor Q4 is operating in the cut-off region, the transistor Q4 can be ignored at this time, so that the transistor Q1 can perform a general switching operation. Thus, the signal PWM1 can be adjusted. The control transistor Q1 is turned on and off, so that the magnetic coil L1 can perform switching between the action and the stop action to achieve the desired requirement of the DC motor speed frequency 16 200847614. In this embodiment, the transistor Q4 is Electrical The transistor Q1 is electrically coupled to the wafer output terminal DO via a resistor, and in another embodiment, the transistor Q4 is electrically coupled to the transistor Q2 and electrically coupled to the wafer via a resistor. Output terminal DOB. Referring to Fig. 12, there is shown a schematic diagram of a driving circuit of a DC motor according to a seventh embodiment of the present invention including a PWM control circuit. Compared with Fig. 11, the driving circuit 3 00f further includes A switch Q5, and in this example the switch Q5 is also a PNP type bipolar junction transistor. The control terminal of the transistor Q5, that is, the base terminal, is used to receive another pulse width modulation signal PWM2, the emitter end The collector is electrically coupled to the high DC voltage VCC, and the collector is electrically coupled to the base terminal of the transistor Q2 and electrically coupled to the wafer output terminal DOB of the 1C wafer 302 via the resistor R2. In this way, the on and off of the transistors Q1 and Q2 can be controlled by adjusting the signals PWM1 and PWM2, so that the magnetic coils L1 and L2 can be switched between the respective action and the stop action to achieve the speed of the DC motor. The frequency meets the required requirements at the same time. Referring to FIG. 13, a schematic diagram of a driving circuit of a DC motor including a rotational frequency detecting signal generating circuit and a PWM control circuit according to an eighth embodiment of the present invention is shown. Compared with FIG. 12, the driving circuit 300g further includes two switches Q6 and Q7, and in this example, the switch Q6 is a PNP type bipolar junction transistor, and the switch Q7 is an NPN bipolar. Junction transistor. The control terminal 'the base terminal' of the transistor Q 6 is electrically coupled to the base terminal of the transistor Q2 and the collector terminal of the transistor Q5 via the resistors R7 and R2, and is electrically coupled to the chip output end of the 1C wafer 302. DOB, and the emitter pole of the transistor Q6 is electrically coupled to the high DC voltage VCC. The crystal terminal 17 200847614 is the terminal end of the control terminal, which is electrically connected to the collector terminal of the transistor Q0 via the series-connected resistor R8, and is connected to the ground terminal GND, the transistor Q7, and electrically connected to the rxm body. The emitter of the Q7 is electrically connected to the grounding G, while the collector of the electric Japanese and Japanese Q7 is used to output the motor speed. (4) Γ2: The control system performs the speed of the DC fan motor. system. In this way, by changing the pulse width modulation signal, 2 simultaneously detecting the rotational frequency of the DC fan motor to obtain the motor rotation frequency. Γ Referring to Fig. 14, there is shown a schematic diagram of the connection of an internal driving circuit of an IC chip according to another embodiment of the present invention to an external circuit. Compared with FIG. 6, the 1C chip 302a may further include two switches Qc and %, and in this example, the switches Qc and qd are respectively an npn-type bipolar junction transistor. The base terminal receives a control voltage signal, and the emitter is electrically connected to the base end of the transistor qd〇, and is electrically connected to the ground GND via a series resistor Rc, and the collector is connected to the ground terminal GND. The series resistor RE is electrically connected to the reference high voltage VDD. The base extreme of the transistor % receives the control-voltage signal Vd, and its emitter is electrically connected to the base end of the Q-plane of the transistor, and is connected to the ground via a series-connected resistor and an electrical surface, GND' The extreme is electrically connected to the reference high voltage VDD via a series resistor Rp. Wherein, the t crystals Qc and Qd are respectively turned on at different times to receive the control voltage signal Vc^Vd, and the control electric (4) % and VD can be generated according to the magnetic sensing element and the control circuit in the 1C wafer. When the transistor Qc receives the control voltage signal Vc and turns on, the node C is in a high level state, so that the transistor Qd. Turn on, and the transistor Q1 is turned on to drive the magnetic coil L1. When the transistor Qc is received as a low voltage, the voltage is turned off, the node C is in the low level, and the transistor Q1 is turned off. The ... is controlled by the transistor Qd to receive the control signal VD, so that D is in a high level state, the transistor Qdob is turned on, and the transistor 2 is also turned on to drive the magnetic coil 12. The magnetic coils ^ and u are operated by the conversion of the continuous high and low voltages of the control voltages 仏唬Vc and ν〇.

Referring to FIG. 15, a schematic diagram showing the connection of an internal driving circuit of an ic chip to an external circuit according to still another embodiment of the present invention is shown. In comparison with Fig. 14, the IC chip 3〇2b may further include a switch Qe, and in this example, the switch QE is a -NPN type bipolar junction transistor. The control of the transistor is the base extreme, which is electrically connected to the reference high voltage VDD. The set of extreme electrical properties is high DC voltage VCC, and the emitter end is connected to the transistor Qd via the series resistor REf. The extreme of the set. Here, when the control voltage signals ^ and Vd repeatedly switch between the transistors ^ and Qd, the reference high voltage VDD, the transistor qe, and the series resistor Re can be used to stabilize the current flowing through the transistors (^ and Qd). The principle and competition of the f. Because the transistor used to drive the magnetic coil will be turned on and off repeatedly according to the control signal, the current flowing through the magnetic coil will instantaneously change the size of the large towel. The change in the magnetic field induces a counter electromotive force' and this repeated transient high voltage causes continuous noise in the magnetic coil and the entire fan motor. The magnitude of the change in the back electromotive force can be obtained by the following equation: 19 200847614 dV = L * Di/dt where dV is the voltage change induced by the change in current flowing through the magnetic coil 'L is the inductance value of the magnetic coil' and di/dt is the instantaneous rate of change of the current flowing through the magnetic coil with respect to time. If the instantaneous change of the current flowing through the magnetic coil can be reduced, the voltage change can be reduced, thereby reducing the noise generated by the motor.

L The following describes an analysis of the driving circuit of the embodiment of the present invention. Referring again to Figure 6, in the case of a transistor (^〇 and transistor), the currents IC1 and IC2 generated by the collectors are represented by the following equation:

Ici = Is * exp(Vbel/yT)

Ic2 = Is * exp(Vbe2/VT) where Is is a current amplification constant and VT is a thermal voltage that varies with temperature. In addition, icl + iC2 = I, and vbel-vbe2 = Vdo_Vd〇b = Vid, where the system flows through the extreme current of the set of QA, so after the operation derivation, equations (1) and (2) can be obtained.

Ici = 1/(1+ exp(_vid/VT)) (1)

Ic2 - 1/(1+ exp(Vid/yT)) (2) μ Refer to Figure 16 for a partial waveform of the current over time at the collector extremes of the transistors Qdo and Qdob in the drive circuit of Figure 6 . It can be seen from the equations and equations (1) and (7) that when the transistors % and q are in the switching action of turning on and off, that is, in the switching time dt, the current

The size of Ic^Ic2 will change according to the electric Vid, and will exhibit an approximately linear change'. Therefore, the instantaneous change rate di/dt of the current flowing through the magnetic coil of the magnetic coil is also approximated. Also, the horse hoist number; that is, the voltage across the magnetic coil is hardly instantaneous, so the noise generated by the motor unit 20 200847614 can be relatively reduced. Further, the current flowing through the terminals Qd〇 and Qd〇b of the transistor is amplified by the constant voltage driving of the transistors Q1 and Q2, so that it can be applied to a fan motor of high rotation speed and high current.

Please refer to Fig. 17, which is a measurement waveform diagram of the output voltage of the DC voltage source and the terminal terminals D〇 and D〇B when the high DC voltage is 12V in Fig. 6. It can be clearly seen from the figure that the back electromotive force that may have been generated almost no longer exists, and the DC voltage source is no longer interfered by any power mulberry. The noise problem that the motor may cause has been solved. Please refer to Fig. 18, which shows the measurement waveform of the output voltages of the output terminals DO and D〇B when the high DC voltage is 12v, and the corresponding spectrum diagram. It can be clearly seen from the figure that the ratio of the even-numbered frequencies has been reduced, and the odd-numbered frequencies are almost negligible after a certain multiple (e.g., 9 times), and the convergence thereof is remarkably improved. Please refer to Figure 19 for the measurement waveform of the output voltage of the DC voltage source and the terminal DO and the DOB when the high DC voltage is 24V in Figure 6. It can be clearly seen from the figure that when the DC voltage is increased for driving, the output voltage waveforms of the output terminals D〇' and D〇B are still quite C疋 and the DC voltage source is not interfered by any power supply noise. This also does not have a yoke voltage value that is not too large for this driver circuit. Referring to Fig. 20, the measurement waveform of the output voltage of the output terminal, the point DO, and the D0B when the high DC voltage is (10) in Fig. 6 and the corresponding spectrum diagram are shown. It can be clearly seen from the figure that the convergence is also significantly improved. According to the embodiment of the present invention, the driving circuit using the DC motor can simultaneously include the advantages of constant current driving and constant power driving, and not only 21 200847614 can reduce the noise caused by the motor, and is suitable for high speed and high current. The application of the. Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any person skilled in the art can make various changes without departing from the spirit and scope of the invention. The above and other objects, features, advantages and embodiments of the present invention will become more apparent and understood by the appended claims. The detailed description of the drawings is as follows: Fig. 1A shows a conventional driving circuit using a constant voltage output. Figure 1B shows a measurement waveform of the DC voltage source and the output voltages of the output terminals D〇 and d〇b. Figure 1C shows the output/voltage waveforms of the output terminals D〇 and d〇B and their corresponding spectrums. Fig. 2 is a diagram showing a conventional driving circuit using a constant current output. . Fig. 3 is a view showing a zone 1 dynamic circuit of a direct current motor according to a first embodiment of the present invention. Fig. 4 is a view showing a driving circuit of a direct current motor according to a second embodiment of the present invention. Fig. 5 is a schematic view showing the circuit block inside the integrated circuit wafer in Fig. 3. Figure 6 is a schematic diagram showing the internal driving of a 1C wafer in accordance with an embodiment of the present invention. Fig. 7 is a view showing a driving circuit of a direct current motor according to a third embodiment of the present invention. Figure 8 is a schematic diagram showing the driving of a DC motor according to a fourth embodiment of the present invention, the circuit including a rotational frequency detecting signal generating circuit. Fig. 9 is a graph showing the measurement waveforms of the voltages of the output terminals D〇' and D〇B, and the rotational frequency detection signals in Fig. 8. Fig. 10 is a view showing a driving circuit of a DC motor according to a fifth embodiment of the present invention comprising a rotational frequency (four) measuring signal generating circuit. Figure 11 is a diagram showing a drive circuit of a DC motor according to a sixth embodiment of the present invention including a PWM control circuit. Figure 12 is a schematic diagram showing the driving circuit of a DC motor according to a seventh embodiment of the present invention including a PWM control circuit. Fig. 13 is a view showing a drive circuit of a DC motor according to an eighth embodiment of the present invention, which includes a rotational speed frequency detecting signal generating circuit and a pwM control circuit. Figure 14 is a diagram showing the connection of an internal driving circuit of an ic chip to an external circuit in accordance with another embodiment of the present invention. Figure 15 is a schematic view showing the connection between the internal driving circuit of the wafer and the external circuit in accordance with the present invention. Figure 16 is a diagram showing the set of electro-crystal (4) (10) and q-plane in the driving circuit of Figure 6 Schematic diagram of the waveform of the extreme current over time. Figure 17 shows the measurement waveform of the output voltage of the DC source and the output terminal DO and DOB when the high DC voltage is i2v in Figure 6. 200847614 Figure 18 is a diagram showing the measured waveforms of the output voltages of the output terminals DO' and DOB' when the high DC voltage is 12V in Fig. 6 and its corresponding spectrum diagram. Figure 19 shows the sixth picture. In the figure, when the high DC voltage is 24V, the DC voltage source and the output voltages of the output terminals DO' and DOB' are measured. Fig. 20 shows the output when the high DC voltage is 24V in Fig. 6. The measured waveforms of the output voltages of the points DO' and DOB' and their corresponding spectrograms. [Description of main components] 100, 200, 300, 300a to 300i: drive circuits 302, 302a, 302b, 303: integrated circuits Wafers Q1 to Q7, Qdo, Qdob, Qa~Qe: Bipolar junction transistor 24

Claims (1)

200847614 X. Patent application scope: A constant current constant voltage driving circuit for a DC motor, the DC magnetic field 2: a first magnetic coil and a second magnetic coil, wherein the first -= circle ί has a first-end point and - a second end point, the second magnetic line ', the two end points, and a fourth end point, and the second end point and the fourth (four) point are electrically coupled to the H test, the drive (four) way includes: A Φ 2々日 U. n Λ.Α- _ chip output; Γ - first switch, with - first control end, a fifth end one: six end, 'where the first _ control end Electrically lightly connected to the first chip output end of the integrated circuit crystal, the fifth end point is electrically coupled to a second reference voltage, and the sixth end point is electrically coupled to the first magnetic field The first end of the coil; and the second switch of the mountain, having a second control end, a seventh end point, and a second end point, wherein the second control end is electrically coupled to the integrated circuit chip The second chip output end is electrically coupled to the second end The integrated circuit chip has a first 曰山山,, a lyrics output terminal, and a f-th voltage, the eighth end is electrically coupled to the third end of the second magnetic coil; ^ Eight. The first switch and the second open relationship are respectively turned on at different times according to a first current and a second current flowing through the wafer rounding end and the second wafer output end respectively, thereby driving the first The magnetic ί S and the second current coil '丨 of the first current or the second current of the babe are -^ value, and the first magnetic coil and the second magnetic coil are divided into different times according to the The first switch and the second switch are each driven by a certain voltage generated by the second switch. 25 200847614 T Continued to find the first open relationship of the first item of the 槌 槌 为 - 第 第 第 第 第 第 第 = = = = = = = = 第二 第二 第二 第二 第二 第二 第二 第二 第二 第二 第二 第二 第二 第二 第二 第二 第二 第二 第二 第二 第二 第二The open-faced transistor and the second PNP-type bipolar and two-s P-type bipolar-connected circuit wafers are respectively turned on according to the integrated body for the first current and the second current:: Zone 2: and ======================================================================================== The seventh point and the eighth end point are respectively the driving circuit of the base of the δ χ body, the emitter end, and the set 2 of the clear type bipolar junction electro-crystal-gate patent (4), wherein the The:: ΡΝ-type bipolar junction transistor, the second open-junction transistor and the first-NPNH- νρν-type bipolar circuit 4 are respectively in the saturation region, The first current and the second current are amplified, and the fifth end point and the sixth end point of the first control I are respectively the first-type bipolar connection=electric crystal The base terminal, the emitter terminal and the collector terminal, the second control terminal, the seven-end terminal and the eighth terminal are respectively a base terminal, an emitter terminal and a collector terminal of the second die-type bipolar junction transistor . The driving circuit of the first aspect of the invention, further comprising: a first resistor electrically coupled to the first chip output end of the integrated circuit chip and the first control end of the first switch And the driving circuit of the second crystal, such as the application of the second aspect of the invention, further comprising a first valley, electrically coupled to the sixth end of the first switch a second capacitor electrically coupled to the eighth end of the second switch The driving circuit of the fifth aspect of the invention includes: the driving circuit of the fifth item, wherein the third resistor of the second month is electrically coupled to the sixth end of the first switch and the capacitor And the fourth resistor is electrically coupled between the eighth end of the second switch and the second capacitor. 7. The driving circuit of claim 1, further comprising: a third NPN type bipolar junction transistor having a third control end, a ninth end point, and a tenth end point, The third control terminal is electrically coupled to the eighth end of the second switch and the third end of the second magnetic coil, the ninth end is configured to output a voltage detection signal, The tenth end point is electrically coupled to the first reference voltage, and the third control end, the ninth end point, and the tenth end point are respectively base ends of the third NPN type bipolar junction transistor And a fifth resistor electrically coupled between the second control terminal of the third NPN-type bipolar junction transistor and the eighth terminal of the second switch. 27 200847614 8·If you want to cover the driving circuit described in item 7, the electric system is the motor speed frequency detection signal. 2. The driving circuit as described in claim 7 of the patent scope, further comprising: a resistor, the electrical surface being connected to the first and the first capacitor - m _ of the six-terminal end with C and ^ = The resistance is based on the first of the second switch and the capacitor. • The drive circuit as described in claim 1 of the patent scope further includes: a flute:: four PNP-type bipolar junction transistor 'has a fourth control terminal, · connects # 1 point and - tenth & quot An end point, wherein the first ton end uses the first-phase pulse width modulation signal, and the eleventh end point is electrically coupled to the human 彳 voltage 'the twelfth end point is electrically connected The first switch = the control terminal, and the tenth time, the tenth end point, and the first & point are respectively a base emitter extreme and a set terminal of the fourth PNP type bipolar junction transistor . 11 · The driving circuit as described in the scope of application for the patent scope includes: a rape-five-type PNP-type bipolar junction electric day and day body, having - fifth control end 3, 23 end point and one a fourteenth end point, wherein the fifth control end uses: a first pulse width modulation signal, the thirteenth end point is electrically coupled to a second reference voltage of the fourth threshold The first control terminal of the first 幵m and the first chip transmission 28 200847614 of the integrated circuit chip; and: a sixth ΡΝΡ type bipolar junction transistor having a sixth control Receiving - second pulse width modulation == two reference voltages, the sixteenth endpoint = the second control terminal and the second chip of the integrated circuit chip are Γ (four) five (four) end, (four) thirteen The end point of the end point is divided into extremes... the base end of the 双-type bipolar junction transistor, the emitter end and the set are =1 to six control difficulties, the fifteenth end point and (four) sixteen end points are extreme ', The base terminal, the emitter end and the set of the 双-type bipolar junction transistor, such as the driving circuit described in the patent application scope , further comprising: a “seventh-type bipolar junction transistor having a seventh control terminal, a seventeenth terminal, and an eighteenth terminal, wherein the seventh control terminal is electrically connected to the light The mth second control end, the sixteenth end of the sixth clear bipolar neodymium body, and the second buck wheel of the integrated circuit chip, the end of the seventeenth end The point system is electrically pure to the second reference voltage; a #1 person ΝΡΝ type bipolar junction transistor having a _ first control end, a nineteen end point, and a twentieth end point, wherein the first person controls The end system is connected to the tenth end of the seventh switch, and the nineteenth end point is connected to the t-pressing debt signal, and the twentieth end point is electrically connected to the first a reference voltage; an eighth resistor electrically coupled to the seventh pNp-type bipolar junction transistor 29 200847614, the seventh control terminal and the second wafer wheel of the integrated circuit chip are between the bats; Nine resistors, electrically connected to the seventh PNP type bipolar junction crystal, the eighteenth end point and the eighth type bipolar junction transistor ^ Between the ends; ^ wherein the seventh control end, the seventeenth end point, and the eighteenth end:: the base end of the seventh PNP type bipolar junction transistor, the emitter end, and the first person control The terminal end, the nineteenth end point, and the twentieth end point of the dipole-type bipolar junction transistor base end, the collector terminal and the shot "13", as described in claim 12, the driving circuit, The electric C Detective 遽 is the _ motor speed frequency speculation signal. I4 · The driving circuit described in claim 1 of the patent scope, the integrated circuit chip in the basin further contains: ', β a magnetic sexy The measuring component is used to measure the change of the magnetic field generated when the DC motor rotates, and rotates a sensing signal; and the control circuit is electrically connected to the magnetic sensing component and receives the sensing "to correspond to the output" At least one control signal; and a driving circuit electrically coupled to the control circuit and receiving the control signal to rotate the corresponding at least one driving signal. I5. The driving circuit of claim 1, wherein the integrated circuit chip further comprises: 30 200847614 - the ninth switch 'has a ninth control terminal, - a twentieth and a twenty-second An endpoint, wherein the twentieth-end is the first crystal output; the tenth switch has a tenth control end, a twenty-third end point, and a twenty-fourth end point, wherein the a twenty-third end point is the second chip output; a certain current source, providing a certain current, and having a twenty-fifth end point to: a twenty-sixth end point, wherein the twenty-fifth end point is electrically coupled to the second end of the ninth switch The twelve-terminal end point and the twenty-fourth end point of the tenth switch are electrically coupled to the first reference voltage. The driving circuit of claim 15, wherein the ninth open relationship is a ninth NPN type bipolar junction transistor, and the ninth control terminal is configured to receive a first control voltage a signal, the first control voltage signal causes the ninth NPN-type bipolar junction transistor to operate in an active region or a section: a region: the tenth open relationship is a tenth deleted bipolar junction transistor, and The tenth control terminal is configured to receive a second control voltage signal, wherein the fourth control voltage (4) causes the tenth NPN type bipolar junction transistor to operate in the active region or the cutoff region, and the ninth control terminal, the The twenty-first end point and the eleventh end point are respectively a base extreme two set extreme and an emitter extreme of the ninth NPN type bipolar junction transistor, and the tenth control end and the thirteenth end point And the first fourteen endpoints of the province are the base extreme, the collector extreme and the emitter extreme of the tenth NpN-type bipolar junction transistor, respectively. 17. The driving circuit of claim 15, wherein the 31 200847614 疋 current source comprises: an eleventh NPN type bipolar junction transistor, the eleventh NPN type bipolar junction transistor Having an eleventh control terminal for receiving a bias voltage such that the eleventh NPN-type bipolar junction transistor operates in the active region and provides a current “and the eleventh control terminal and the twenty-fifth terminal The point and the twenty-sixth end point are respectively a base terminal, a collector terminal and an emitter terminal of the eleventh NPN type bipolar junction transistor. The driving circuit of claim 1 , wherein the integrated circuit chip further comprises: an end, a twenty-seventh end point, and a twenty-eighth end point, wherein the twelfth control end For receiving a third control voltage signal, the twenty-eighth terminal-twelfth NPN type bipolar junction transistor has a twelfth control reference voltage and the ninth control system of the ninth switch Electrically coupled to the first terminal; and a twelfth NPN-type bipolar junction transistor having a thirteenth control-fourth control voltage signal, the thirtieth end point is an electrical reference voltage and the first a tenth control end, a twenty-nine end point, and a thirtieth end of the ten switch, wherein the thirteenth end is configured to be coupled to the first end; 32 200847614 Set extreme and extremes 19. According to the driver circuit described in claim 18, the zhongzhong=12 Qing type bipolar junction transistor and the thirteenth NPN type 雔^ junction transistor The set extremes are connected to the J test voltage through the resistor (10).罘二翏Ο 2〇. The driving circuit described in claim 18, further includes: a terminal, a ^: surface type bipolar junction transistor, having - fourteenth control one twenty one eleven The end point and a thirty-two end point J-terminal end are electrically connected to a third reference voltage, and the thirty-sixth== the second reference voltage 'the thirty-second end point is electrically connected The set extreme of the ^-type bipolar junction transistor and the collector extreme of the thirteenth n-double-turned transistor, and the fourteenth control terminal, the -k point, and the thirty-second endpoint are respectively The base of the fourteen-type tapered pole junction transistor, the extreme set and the extreme. Further, the driving circuit described in the first paragraph of the patent model (4), wherein: the person:: the chip is a four-pin single-in-line package, and the feet: two:: a chip output, the first The output end of the second chip, the third chip output end for the electrical surface=the second reference voltage, and the fourth chip output end for electrically connecting to the first reference voltage. The driving circuit described in claim 1 is applied to drive the electric motor, wherein the circuit is used to drive the brushless fan motor. 33