CN116242094B - Variable frequency control board of refrigerator and control method for switching receiving and transmitting signals - Google Patents

Abstract

The application provides a refrigerator variable frequency control board and a control method for switching receiving and transmitting signals, wherein the refrigerator variable frequency control board comprises a variable frequency board communication circuit and a main control board communication circuit, wherein a first signal receiving and transmitting end of the variable frequency board communication circuit is connected with two identical signal control chips in parallel and is used for switching a first receiving signal pin and a first transmitting signal pin at the first signal receiving and transmitting end; the second signal receiving and transmitting end of the main control board communication circuit is connected with the first signal receiving and transmitting end of the variable frequency board communication circuit through three communication wires. Under the condition that the communication line is reversely connected, the refrigerator variable frequency control board can control the switching between the receiving signal pin and the sending signal pin through the signal control chip so as to ensure the normal communication between the variable frequency board communication circuit and the main control board communication circuit; meanwhile, the frequency conversion board communication circuit is connected with the main control board communication circuit through three communication lines, so that the cost can be reduced, and the wiring error rate can be reduced.

Description

Variable frequency control board of refrigerator and control method for switching receiving and transmitting signals

Technical Field

The application relates to the technical field of refrigerator variable frequency control boards, in particular to a refrigerator variable frequency control board and a control method for switching receiving and transmitting signals.

Background

At present, the communication signal between refrigerator main control board and the frequency conversion board keeps apart each other, connects each other through 4 communication lines between main control board and the frequency conversion board, and the cost is higher.

The 4 communication lines of connecting main control board and frequency conversion board, in case have arbitrary one to connect wrong will lead to the communication unusual, signal between main control board and the frequency conversion board will not normally transmit. The connecting wire between main control board and the frequency conversion board is very inconvenient once the connecting wire is assembled to the complete machine, that is to say, once communication is unusual, the wire harness needs to be changed and consumes very big energy and time, can influence production efficiency.

Disclosure of Invention

The embodiment of the application mainly aims to provide a refrigerator variable frequency control board and a control method for switching receiving and transmitting signals, and aims to ensure normal communication and improve production efficiency by connecting two identical signal control chips in parallel at a first signal receiving and transmitting end of a variable frequency board communication circuit and controlling switching between a receiving signal pin and a transmitting signal pin through the signal control chip under the condition that a connecting wire is reversely connected.

In order to achieve the above objective, a first aspect of an embodiment of the present application provides a variable frequency control board of a refrigerator, including a variable frequency board communication circuit and a main control board communication circuit;

The first signal receiving and transmitting end of the frequency conversion board communication circuit is connected with two identical signal control chips in parallel, and the signal control chips are used for switching a first receiving signal pin and a first transmitting signal pin at the first signal receiving and transmitting end;

The second signal receiving and transmitting end of the main control board communication circuit is connected with the first signal receiving and transmitting end of the variable frequency board communication circuit through three communication lines.

In some embodiments, the first signal transceiver includes a first receive signal pin, a first transmit signal pin, and a first ground pin;

the second signal receiving and transmitting end comprises a second receiving signal pin, a second transmitting signal pin and a second ground wire pin;

the connection mode between the first signal receiving and transmitting end and the second signal receiving and transmitting end comprises:

The first receiving signal pin is connected with the second sending signal pin, the first sending signal pin is connected with the second receiving signal pin, and the first ground wire pin is connected with the second ground wire pin;

or the first receiving signal pin is connected with the second receiving signal pin, the first transmitting signal pin is connected with the second transmitting signal pin, and the first ground wire pin is connected with the second ground wire pin.

In some embodiments, the two identical signal control chips are a first signal control chip and a second signal control chip, respectively;

the first end of the first signal control chip and the first end of the second signal control chip are connected in parallel with the first signal receiving and transmitting end;

the second end of the first signal control chip is connected with the first signal transmitting end of the frequency conversion board communication circuit, and the second end of the second signal control chip is connected with the first signal receiving end of the frequency conversion board communication circuit.

In some embodiments, a first end of the first signal control chip is provided with a first pin, a second pin and a first ground pin, and a second end of the first signal control chip is provided with a third pin, a fourth pin and a first power pin;

A fifth pin, a sixth pin and a second grounding pin are arranged at the first end of the second signal control chip, and a seventh pin, an eighth pin and a second power supply pin are arranged at the second end of the second signal control chip;

The first pin is connected with the sixth pin and is connected with the first transmitting signal pin of the first signal receiving and transmitting end;

the second pin is connected with the fifth pin and is connected with the first receiving signal pin of the first signal receiving and transmitting end;

The first grounding pin and the second grounding pin are connected and then grounded together;

The third pin is connected with the seventh pin and is connected with a control signal together;

the fourth pin is connected to the first signal transmitting end;

the eighth pin is connected to the first signal receiving end;

the first power supply pin and the second power supply pin are both connected with a positive power supply;

When the connection mode between the first signal receiving and transmitting end and the second signal receiving and transmitting end is that the first receiving signal pin is connected with the second transmitting signal pin, the first transmitting signal pin is connected with the second receiving signal pin, the first ground wire pin is connected with the second ground wire pin, the first pin of the first signal control chip is communicated with the fourth pin, and the fifth pin of the second signal control chip is communicated with the eighth pin;

When the connection mode between the first signal receiving and transmitting end and the second signal receiving and transmitting end is that the first receiving signal pin is connected with the second receiving signal pin, the first transmitting signal pin is connected with the second transmitting signal pin and the first ground wire pin is connected with the second ground wire pin, the second pin of the first signal control chip is communicated with the fourth pin, and the sixth pin of the second signal control chip is communicated with the eighth pin.

In some embodiments, a first signal receiving end of the frequency conversion board communication circuit is connected with a first resistance-capacitance filter circuit, and the first resistance-capacitance filter circuit comprises a first capacitor and a first resistor;

The first end of the first resistor is connected with a fourth pin of the second signal control chip, and the second end of the first resistor is connected with the first signal receiving end of the frequency conversion board communication circuit;

The first end of the first capacitor is connected with the second end of the first resistor, and the second end of the first capacitor is grounded.

In some embodiments, the frequency conversion board communication circuit further includes a first triode switch circuit and a first pull-up resistor;

the first end of the first pull-up resistor is connected with the first end of the first resistor, and the second end of the first pull-up resistor is connected with an anode power supply;

The first triode switch circuit is arranged between the first signal transmitting end and the first signal control chip and comprises a second resistor, a first triode, a third resistor, a fourth resistor, a fifth resistor and a second capacitor;

the first end of the second resistor is connected with the first signal transmitting end, and the second end of the second resistor is connected with the first end of the first triode;

The second end of the first triode is connected with a positive electrode power supply, and the third end of the first triode is connected with the first end of the fourth resistor;

the first end of the third resistor is connected with the second end of the second resistor, and the second end of the third resistor is connected with the second end of the first triode;

the second end of the fourth resistor is connected with a fourth pin of the first signal control chip;

the first end of the fifth resistor and the first end of the second capacitor are connected with the second end of the fourth resistor, and the second end of the fifth resistor and the second end of the second capacitor are connected and then grounded together.

In some embodiments, the main control board communication circuit includes a second triode switch circuit, a first optocoupler, a second optocoupler, and a second pull-up resistor;

The second triode switch circuit comprises a sixth resistor, a seventh resistor, a second triode and an eighth resistor;

the first end of the sixth resistor is connected with the second signal transmitting end of the main control board communication circuit, and the second end of the sixth resistor is connected with the first end of the second triode;

the second end of the second triode is connected with the first end of the eighth resistor, and the third end of the second triode is connected with a positive electrode power supply;

The first end of the seventh resistor is connected with the first end of the second triode, and the second end of the seventh resistor is connected with the third end of the second triode;

the second end of the eighth resistor is connected with the first end of the first optocoupler;

the second end of the first optical coupler is connected to the second signal sending pin of the second signal receiving and sending end, and the third end and the fourth end of the first optical coupler are grounded;

The first end of the second optical coupler is connected to the second receiving signal pin of the second signal receiving and transmitting end, the second end of the second optical coupler is connected to the second signal receiving end, and the third end and the fourth end of the second optical coupler are grounded;

the first end of the second pull-up resistor is connected with the second end of the second optocoupler, and the second end of the second pull-up resistor is connected with a positive power supply.

In some embodiments, the second signal receiving end of the main control board communication circuit is connected with a second resistance-capacitance filter circuit, and the second resistance-capacitance filter circuit includes a third capacitor and a ninth resistor;

the first end of the ninth resistor is connected with the second signal receiving end, and the second end of the ninth resistor is connected with the second end of the second optical coupler;

the first end of the third capacitor is connected with the first end of the ninth resistor, and the second end of the third capacitor is grounded.

A second aspect of an embodiment of the present application provides a control method for switching between receiving and transmitting signals, which is executed based on the variable frequency control board of the refrigerator according to the first aspect, and the control method includes:

Determining the current level state of a first signal after the refrigerator is electrified, wherein the first signal is a control signal of a variable frequency control board of the refrigerator, and the level state comprises a high level and a low level;

If the current level state of the first signal is high level, judging whether the communication between the communication circuit of the frequency conversion board and the communication circuit of the main control board is normal or not;

If the communication between the frequency conversion board communication circuit and the main control board communication circuit is abnormal, the level state of the first signal is controlled to be adjusted to be low level, so that a signal control chip in the frequency conversion board communication circuit switches between a received signal pin and a transmitted signal pin according to the first signal, and the communication between the frequency conversion board communication circuit and the main control board communication circuit is recovered to be normal.

In some embodiments, when the communication between the frequency conversion board communication circuit and the main control board communication circuit is normal, the method includes:

and memorizing a first state so as to enable the refrigerator to keep the first state when the refrigerator is electrified next time, wherein the first state is a level state of the first signal in a normal communication state between the variable frequency board communication circuit and the main control board communication circuit.

The application provides a refrigerator variable frequency control board and a control method for switching receiving and transmitting signals, wherein the refrigerator variable frequency control board comprises a variable frequency board communication circuit and a main control board communication circuit, wherein a first signal receiving and transmitting end of the variable frequency board communication circuit is connected with two identical signal control chips in parallel and is used for switching a first receiving signal pin and a first transmitting signal pin at the first signal receiving and transmitting end; the second signal receiving and transmitting end of the main control board communication circuit is connected with the first signal receiving and transmitting end of the variable frequency board communication circuit through three communication wires. Under the condition that the communication line is reversely connected, the refrigerator variable frequency control board can control the switching between the receiving signal pin and the sending signal pin through the signal control chip so as to ensure the normal communication between the variable frequency board communication circuit and the main control board communication circuit; meanwhile, the frequency conversion board communication circuit is connected with the main control board communication circuit through three communication lines, so that the cost can be reduced, and the wiring error rate can be reduced.

Drawings

FIG. 1 is a schematic diagram of connection between a conventional main control board communication circuit and a variable frequency communication circuit according to an embodiment of the present application;

fig. 2 is a circuit configuration diagram of a variable frequency control board of a refrigerator according to an embodiment of the present application;

Fig. 3 is a diagram of a communication circuit of a frequency conversion board according to an embodiment of the present application;

Fig. 4 is a diagram of a communication circuit of a main control board according to an embodiment of the present application;

fig. 5 is a flowchart of steps of a method for controlling switching between transmit and receive signals according to an embodiment of the present application;

fig. 6 is a flowchart of a method for controlling switching of a transmit-receive signal according to an embodiment of the present application.

Detailed Description

The present application will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present application more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.

It should be noted that the terms "first," "second," and the like in the description and the claims, and in the foregoing figures, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of the application only and is not intended to be limiting of the application.

At present, as shown in fig. 1, fig. 1 is a schematic connection diagram of a conventional main control board communication circuit and a variable frequency communication circuit according to an embodiment of the present application. The left part of fig. 1 is a main control board communication circuit, and the right part of fig. 1 is a frequency conversion board communication circuit. The main control board communication circuit and the frequency conversion board communication circuit are connected through 4 communication lines, and are respectively 5V, GND, TXD, RXD signals shown in fig. 1. If any signal wire is connected in error, the communication circuit can not work and report abnormal communication. For refrigerator products, once the connecting wire between the main control board and the frequency conversion board is assembled to the whole refrigerator, the wire harness is inconvenient to replace, and once communication is abnormal, great effort and time are required to be consumed for production.

Based on this, the application provides a refrigerator variable frequency control board, which can automatically adjust the receiving and transmitting signal pins, and referring to fig. 2, fig. 2 is a circuit structure diagram of the refrigerator variable frequency control board provided by the embodiment of the application. The refrigerator variable frequency control board comprises a variable frequency board communication circuit and a main control board communication circuit, wherein:

The first signal receiving and transmitting end of the variable frequency board communication circuit is connected with two identical signal control chips in parallel, and the signal control chips are used for switching a first receiving signal pin and a first transmitting signal pin at the first signal receiving and transmitting end;

The second signal receiving and transmitting end of the main control board communication circuit is connected with the first signal receiving and transmitting end of the variable frequency board communication circuit through three communication wires.

In the embodiment of the application, the first signal receiving and transmitting end of the communication circuit of the variable frequency board is connected with two identical signal control chips in parallel, so that the switching between the signal receiving pin and the signal transmitting pin at the first signal receiving and transmitting end can be independently controlled by the signal control chips under the condition that the connection of communication wires is reversed, and the communication is ensured to be normal; meanwhile, the communication wires are reduced to 3 from four, the connecting wires of the whole machine are simplified, the wiring harness cost can be reduced, the profit margin of the whole machine is increased, meanwhile, one wiring harness is reduced, the production efficiency of a wiring harness manufacturer is also improved, and the wiring error rate can be reduced.

In some embodiments, the first signal transceiver includes a first receive signal pin, a first transmit signal pin, and a first ground pin;

the second signal receiving and transmitting end comprises a second receiving signal pin, a second transmitting signal pin and a second ground wire pin;

The connection mode between the first signal receiving and transmitting end and the second signal receiving and transmitting end comprises:

the first receiving signal pin is connected with the second transmitting signal pin, the first transmitting signal pin is connected with the second receiving signal pin, and the first ground wire pin is connected with the second ground wire pin;

Or the first receiving signal pin is connected with the second receiving signal pin, the first transmitting signal pin is connected with the second transmitting signal pin, and the first ground wire pin is connected with the second ground wire pin.

Specifically, referring to fig. 3 to fig. 4, fig. 3 is a schematic diagram of a communication circuit of a frequency conversion board according to an embodiment of the present application. Fig. 4 is a schematic diagram of a communication circuit of a main control board according to an embodiment of the present application. As shown in fig. 3, CN2 in fig. 3 represents a first signal transceiver, where CN2 includes 1, 2, and 3 pins, i.e., a first transmit signal pin corresponds to 1 pin TX, a first receive signal pin corresponds to 2 pins RX, and a first ground pin corresponds to 3 pins GND. As shown in fig. 4, CN1 in fig. 4 represents a second signal transceiver, and similarly, CN1 also includes 1, 2, and 3 pins in total. The second receiving signal pin corresponds to 1 pin RX, the second transmitting signal pin corresponds to 2 pin TX, and the second ground pin corresponds to 3 pin GND. The connection manner between CN2 in fig. 3 and CN1 in fig. 4 includes:

(1) The 1-pin TX of CN2 is connected with the 1-pin RX of CN1, the 2-pin RX of CN2 is connected with the 2-pin TX of CN1, and the 3-pin GND of CN2 is connected with the 3-pin GND of CN 1.

(2) The 1-pin TX of CN2 is connected with the 2-pin TX of CN1, the 2-pin RX of CN2 is connected with the 1-pin RX of CN1, and the 3-pin GND of CN2 is connected with the 3-pin GND of CN 1.

The connection method (1) is a correct connection method, that is, the correct connection method is: the signal transmission pin (TX) of the frequency conversion board communication circuit end needs to be connected with the signal receiving pin (RX) of the main control board communication circuit end, the signal receiving pin (RX) of the frequency conversion board communication circuit end needs to be connected with the signal transmitting pin (TX) of the main control board communication circuit end, and under the connection mode, the signal control chip does not need to switch the signal receiving pin and the signal transmitting pin at the first signal receiving and transmitting end. The connection mode (2) is to connect the transmitting signal pin (TX) of the communication circuit end of the frequency conversion board with the transmitting signal pin (TX) of the communication circuit end of the main control board, connect the receiving signal pin (RX) of the communication circuit end of the frequency conversion board with the receiving signal pin (RX) of the communication circuit end of the main control board, namely 2 communication lines are reversely connected, and at this time, the signal control chip is required to switch the receiving signal pin and the transmitting signal pin at the first signal receiving and transmitting end, so that the communication between the communication circuit of the frequency conversion board and the communication circuit of the main control board can be ensured to be normal. That is, when the connection lines of the transmission signal and the reception signal are connected reversely, the connection relationship can be corrected by the control signal control chip. Therefore, production personnel do not need to check faults, the wire harness is replaced, the production efficiency can be improved, and the yield of products in the off-line process can be improved.

Referring to fig. 3, an IC1 shown in fig. 3 is a first signal control chip, an IC2 is a second signal control chip, and CN2 is a first signal receiving and transmitting end. As shown in fig. 3, the first end of the first signal control chip IC1 and the first end of the second signal control chip IC2 are connected in parallel to one end of the first signal receiving/transmitting end CN 2. The second end of the first signal control chip IC1 is connected to a first signal transmitting end PWM-TX of the frequency conversion board communication circuit. The second end of the second signal control chip IC2 is connected to the first signal receiving end PWM-RX of the frequency conversion board communication circuit.

As shown in fig. 3, the first signal control chip IC1 is provided with a first pin B1, a first ground pin GND and a second pin B0, and the second end of the first signal control chip IC1 is provided with a third pin S, a first power supply pin VCC and a fourth pin a; the second signal control chip IC2 has the same structure as the first signal control chip IC 1.

As shown in fig. 3, a first end of the second signal control chip IC2 is provided with a fifth pin B1, a second ground pin GND and a sixth pin B0, and a second end of the second signal control chip IC2 is provided with a seventh pin S, a second power pin VCC and an eighth pin a.

The first pin B1 is connected with the sixth pin B0 and is connected with the 1 pin TX of the first signal receiving and transmitting end CN 2;

the second pin B0 is connected with the fifth pin B1 and is connected with the 2 pin RX of the first signal receiving and transmitting end CN 2;

the first grounding pin GND is connected with the second grounding pin GND and then is grounded;

The third pin S is connected with the seventh pin S and is connected with the SW signal together;

the fourth pin A is connected to the first signal transmitting end PWM-TX;

The eighth pin A is connected with a first signal receiving end PWM-RX;

the first power supply pin VCC and the second power supply pin VCC are both connected with +5VB;

When the connection mode between the communication circuit of the frequency conversion board and the communication circuit of the main control board is the aforementioned connection mode (1), that is, when the connection mode between the first signal receiving and transmitting end CN2 and the second signal receiving and transmitting end CN1 is that the first receiving signal pin RX is connected with the second transmitting signal pin TX, the first transmitting signal pin TX is connected with the second receiving signal pin RX, and the first ground wire pin GND is connected with the second ground wire pin GND, the first pin B1 of the first signal control chip IC1 is communicated with the fourth pin a, and the fifth pin B1 of the second signal control chip IC2 is communicated with the eighth pin a;

When the connection mode between the communication circuit of the frequency conversion board and the communication circuit of the main control board is the aforementioned connection mode (2), that is, when the connection mode between the first signal receiving and transmitting end CN2 and the second signal receiving and transmitting end CN1 is that the first receiving signal pin RX is connected with the second receiving signal pin RX, the first transmitting signal pin TX is connected with the second transmitting signal pin TX, and the first ground wire pin GND is connected with the second ground wire pin GND, the second pin B0 of the first signal control chip IC1 is communicated with the fourth pin a, and the sixth pin B0 of the second signal control chip IC2 is communicated with the eighth pin a.

As shown in fig. 3, a first signal receiving end PWM-RX of the frequency conversion board communication circuit is connected with a first rc filter circuit. The first resistance-capacitance filter circuit comprises a first capacitor C650 and a first resistor R147;

The first end of the first resistor R147 is connected with the fourth pin A of the second signal control chip IC2, and the second end of the first resistor R147 is connected with the first signal receiving end PWM-RX of the frequency conversion board communication circuit;

A first end of the first capacitor C650 is connected to a second end of the first resistor R147, and a second end of the first capacitor C650 is grounded.

As shown in fig. 3, the frequency conversion board communication circuit further includes a first triode switch circuit and a first pull-up resistor R612;

A first end of the first pull-up resistor R612 is connected with a first end of the first resistor R147, and a second end of the first pull-up resistor R612 is connected with the positive power supply +5VB;

The first triode switch circuit is arranged between the first signal transmitting end PWM-TX and the first signal control chip IC1 and comprises a second resistor R38, a first triode P602, a third resistor R661, a fourth resistor R662, a fifth resistor R663 and a second capacitor C649;

a first end of the second resistor R38 is connected to the first signal transmitting end PWM-TX, and a second end of the second resistor R38 is connected to the first end of the first triode P602;

A second end of the first triode P602 is connected with a positive electrode power supply +5VB, and a third end of the first triode P602 is connected with a first end of a fourth resistor R662;

the first end of the third resistor R661 is connected with the second end of the second resistor R38, and the second end of the third resistor R661 is connected with the second end of the first triode P602;

The second end of the fourth resistor R662 is connected with a fourth pin A of the first signal control chip IC 1;

The first end of the fifth resistor R663 and the first end of the second capacitor C649 are both connected with the second end of the fourth resistor R662, and the second end of the fifth resistor R663 and the second end of the second capacitor C649 are connected with the ground at the frequency conversion plate.

In addition, as shown in fig. 3, the third pin S of the first signal control chip IC1 and the seventh pin S of the second signal control chip IC2 are connected and then connected with an SW signal, when the SW signal is at a high level, the first signal control chip IC1 and the second signal control chip IC2 are communicated with each other with B1 and a, and when the SW signal is at a low level, the first signal control chip IC1 and the second signal control chip IC2 are communicated with each other with B0 and a. That is, the signal control chip may be adjusted to allow B1 to communicate with a or B0 to communicate with a by adjusting the level state of the SW signal.

For example, as shown in fig. 3, in the embodiment of the present application, the first signal control chip IC1 and the second signal control chip IC2 may each be a chip of model UTAS and 4157. The model of the signal control chip is not particularly limited in the embodiment of the application, so long as the chip with the same or similar function as the UTAS4157 chip can be realized.

As shown in fig. 4, the main control board communication circuit includes a second triode switch circuit, a first optocoupler IC603, a second optocoupler IC664 and a second pull-up resistor R135;

the second triode switch circuit comprises a sixth resistor R617, a seventh resistor R140, a second triode P601 and an eighth resistor R158;

The first end of the sixth resistor R617 is connected with the second signal transmitting end M-TX of the main control board communication circuit, and the second end of the sixth resistor R617 is connected with the first end of the second triode P601;

The second end of the second triode P601 is connected with the first end of the eighth resistor R158, and the third end of the second triode P601 is connected with the positive electrode power supply +5V;

The first end of the seventh resistor R140 is connected with the first end of the second triode P601, and the second end of the seventh resistor R140 is connected with the third end of the second triode P601;

the second end of the eighth resistor R158 is connected to the first end of the first optocoupler IC 603;

The second end of the first optocoupler IC603 is connected to a second transmitting signal pin TX of a second signal receiving and transmitting end CN1, the third end of the first optocoupler IC603 is connected with the ground at the main control board, and the fourth end of the first optocoupler IC603 is connected with the ground at the variable frequency board;

The first end of the second optocoupler IC664 is connected to a second receiving signal pin RX of the second signal receiving and transmitting end CN1, the second end of the second optocoupler IC664 is connected to a second signal receiving end M-RX, the third end of the second optocoupler IC664 is connected to the ground at the main control board, and the fourth end of the second optocoupler IC664 is connected to the ground at the frequency conversion board;

the first end of the second pull-up resistor R135 is connected to the second end of the second optocoupler IC664, and the second end of the second pull-up resistor R135 is connected to the positive power supply +5v.

It should be noted that, the ground at the main control board is isolated from the ground at the frequency conversion board, so that the ground wire or the zero wire needs to be paid attention to specifically connect the ground at the main control board or the ground at the frequency conversion board.

As shown in fig. 4, a second signal receiving end of the main control board communication circuit is connected with a second resistance-capacitance filter circuit, and the second resistance-capacitance filter circuit comprises a third capacitor C8 and a ninth resistor R113;

The first end of the ninth resistor R113 is connected with the second signal receiving end M-RX of the main control board communication circuit, and the second end of the ninth resistor R113 is connected with the second end of the second optocoupler IC 664;

The first end of the third capacitor C8 is connected with the first end of the ninth resistor R113, and the second end of the third capacitor C8 is connected with the ground at the main control board.

In addition, as shown in fig. 4, the main control board communication circuit further includes a resistor R137 and a diode D660 connected to the third end of the first optocoupler IC603, where the other end of the resistor R137 and the other end of the diode D660 are connected to the first end of the first optocoupler IC603, so as to facilitate the switch control of the first optocoupler IC 603.

In the embodiment of the present application, if the connection relationship between the second signal receiving and transmitting end CN1 of the main control board communication circuit and the first signal receiving and transmitting end CN2 of the frequency conversion board communication circuit is correct, that is, the 1 pin TX of CN2 is connected with the 1 pin RX of CN1, the 2 pin RX of CN2 is connected with the 2 pin TX of CN1, the 3 pin GND of CN2 is connected with the 3 pin GND of CN1, then the SW signal is at high level, and the first signal control chip IC1 is communicated with the B1 and the a in the second signal control chip IC 2.

At this time, the loop that the main control board communication circuit sends to the frequency conversion board communication circuit and receives is as follows:

The M-TX at the communication circuit side of the main control board is a transmitting signal, and after passing through the second triode P601 and the first optocoupler IC603, the signal reaches the 2 pin TX of the CN1 and then the 2 pin RX at the communication circuit side CN2 of the frequency conversion board, and because the SW at the moment is in a high level, the B1 is communicated with the A, the signal can reach the A pin of the IC2 through the B1 of the IC2, and then reaches the PWM-RX position of the pin of the singlechip at the communication circuit side of the frequency conversion board.

Specifically, if the M-TX signal sent from the main control board communication circuit side is at a high level, the second triode P601 is not turned on, and the first optocoupler IC603 is also not turned on, so that the PWM-RX signal reaching the inverter board communication circuit side is pulled up to 5V by the first pull-up resistor R612, so that the PWM-RX signal is also at a high level.

Similarly, if the master control board communication circuit side sends the M-TX signal to be at low level, the second triode P601 is turned on, and the first optocoupler IC603 is also turned on, so that the PWM-RX signal reaching the frequency conversion board communication circuit side is pulled down to the ground GND due to the conduction of the first optocoupler IC603, so that the PWM-RX signal is also at low level.

The loop that the communication circuit of the frequency conversion board sends to the communication circuit of the main control board and receives is as follows:

the PWM-TX at the communication circuit side of the frequency conversion board is a transmitting signal, and reaches the A of the IC1 through the first triode P602, because SW is at a high level at this time, B1 is communicated with A, so that the signal reaches the 1 pin TX of CN2 after reaching the B1 of the IC1 through the A of the IC1, then reaches the 1 pin RX of CN1 at the communication circuit side of the main control board, then passes through the second optocoupler IC664, and then reaches the pin M-RX of the singlechip at the communication circuit side of the main control board.

Specifically, if the PWM-TX signal sent from the communication circuit side of the frequency conversion board is at a high level, the first triode P602 is not turned on, and the second optocoupler IC664 is also not turned on, so that the M-RX signal reaching the communication circuit side of the main control board is pulled up to 5V by the second pull-up resistor R135, so that the M-RX signal is also at a high level.

Similarly, if the PWM-TX signal sent from the communication circuit side of the inverter board is at a low level, the first triode P602 is turned on, and the second optocoupler IC664 is also turned on, so that the M-RX signal reaching the communication circuit side of the main control board is pulled down to the ground GND due to the optocoupler conduction, so that the M-RX signal is also at a low level.

It can be understood that in the embodiment of the present application, when the connection relationship between the main control board communication circuit and the frequency conversion board communication circuit is correct, the SW signal is at a high level, and when the SW signal is at a high level, the first signal control chip IC1 and the second signal control chip IC2 are in communication with each other with B1 and a. At this time, the main control board communication circuit sends to the loop that the frequency conversion board communication circuit receives, send the signal to pass through CN 1's 2 pin TX and transmit to CN 2's 2 pin RX; the communication circuit of the frequency conversion board sends the signal to the loop received by the communication circuit of the main control board, and the sending signal is transmitted to the 1 pin RX of CN1 through the 1 pin TX of CN 2.

In the embodiment of the present application, if the connection relationship between the second signal receiving and transmitting end CN1 of the main control board communication circuit and the first signal receiving and transmitting end CN2 of the frequency conversion board communication circuit is incorrect, that is, the 1 pin TX of CN2 is connected with the 2 pin TX of CN1, the 2 pin RX of CN2 is connected with the 1 pin RX of CN1, the 3 pin GND of CN2 is connected with the 3 pin GND of CN1, then the SW signal is at low level, and the B0 and a in the first signal control chip IC1 and the second signal control chip IC2 are communicated.

At this time, the loop that the main control board communication circuit sends to the frequency conversion board communication circuit and receives is as follows:

the M-TX at the communication circuit side of the main control board is a transmitting signal, and after passing through the second triode P601 and the first optocoupler IC603, the signal reaches the 2 pin TX of CN1 and then reaches the 1 pin TX of CN2, and because SW is at a low level at this time, B0 is communicated with A, the signal reaches the A of IC2 through the B0 of IC2, and then reaches the pin PWM-RX of the singlechip at the communication circuit side of the frequency conversion board.

Specifically, if the M-TX signal sent by the main control board communication circuit is at a high level, the second triode P601 is not turned on, and the first optocoupler IC603 is also not turned on, so that the PWM-RX signal reaching the inverter board communication circuit side is pulled up to 5V by the first pull-up resistor R612, so that the PWM-RX signal is also at a high level.

Similarly, if the M-TX signal sent by the main control board communication circuit is at a low level, the second triode P601 is turned on, and the first optocoupler IC603 is also turned on, so that the PWM-RX signal reaching the inverter board communication circuit side is pulled down to the ground GND due to the conduction of the first optocoupler IC603, so that the PWM-RX signal is also at a low level.

The loop that the communication circuit of the frequency conversion board sends to the communication circuit of the main control board and receives is as follows:

the PWM-TX on the communication circuit side of the frequency conversion board is a transmission signal, and reaches the a of the IC1 through the first triode P602, because SW is at a low level at this time, B0 is communicated with a, so that the signal reaches the 2 pin RX of CN2 after reaching the B0 of IC1 through the a of IC1, then reaches the 1 pin RX of CN1, then passes through the second optocoupler IC664, and then reaches the pin M-RX of the singlechip on the communication circuit side of the main control board.

Specifically, if the PWM-TX signal sent from the communication circuit side of the frequency conversion board is at a high level, the first triode P602 is not turned on, and the second optocoupler IC664 is also not turned on, so that the M-RX signal reaching the communication circuit side of the main control board is pulled up to 5V by the second pull-up resistor R135, so that the M-RX signal is also at a high level.

Similarly, if the PWM-TX signal sent from the communication circuit side of the inverter board is at a low level, the first triode P602 is turned on, and the second optocoupler IC664 is also turned on, so that the M-RX signal reaching the communication circuit side of the main control board is pulled down to the ground GND due to the optocoupler conduction, so that the M-RX signal is also at a low level.

It can be understood that in the embodiment of the present application, when the connection relationship between the main control board communication circuit and the frequency conversion board communication circuit is incorrect, the SW signal is at a low level, and when the SW signal is at a low level, the first signal control chip IC1 and the second signal control chip IC2 are in communication with each other with B0 and a. At this time, the main control board communication circuit sends to the loop that the frequency conversion board communication circuit receives, send the signal to transmit to the 1 pin TX of CN2 through 2 pin TX of CN 1; the communication circuit of the frequency conversion board sends a sending signal to a loop received by the communication circuit of the main control board, and the sending signal is transmitted to the 1 pin RX of CN1 through the 2 pin RX of CN 2.

It should be noted that, in the embodiment of the present application, when the connection relationship between the main control board communication circuit and the variable frequency board communication circuit is incorrect, the main control board communication circuit sends the signal to the loop received by the variable frequency board communication circuit, and the SW signal is set to be low level, so that the B0 and the a in the second signal control chip IC2 are turned on, so that the 1 pin TX and the 2 pin RX at the CN2 can be switched, that is, the signal sent by the main control board communication circuit is still transferred from the 2 pin TX of CN1 to the 1 pin TX of CN2 on the circuit path, but the 1 pin of CN2 has actually become the receiving signal pin RX through the processing of the second signal control chip IC 2. Thus, the signal can be smoothly transmitted. Similarly, the frequency conversion board communication circuit sends to the loop received by the main control board communication circuit, by setting the SW signal to be low level, so that B0 and a in the first signal control chip IC1 are conducted, so that the 1 pin TX and 2 pin RX at CN2 can be switched as well, that is, the signal sent by the frequency conversion board communication circuit is still transferred from 2 pin RX of CN2 to 1 pin RX of CN1 on the line path, but through the processing of the first signal control chip IC1, the 2 pin of CN2 has actually become the sending signal pin TX. Thus, the signal can be smoothly transmitted. That is, the signal control chips IC1 and IC2 can realize switching between the reception signal pin and the transmission signal pin at CN2 by conducting switching to the circuit line. That is, the 1 pin of CN2 may be controlled to be the transmit signal pin TX and the 2 pin to be the receive signal pin RX; the 1 pin of CN2 may also be controlled to be the receive signal pin RX, and the 2 pin may be controlled to be the transmit signal pin TX.

Referring to fig. 5, fig. 5 is a step flowchart of a control method for switching between receiving and transmitting signals according to an embodiment of the present application, which is performed by the variable frequency control board of the refrigerator shown in fig. 2, including but not limited to steps S501 to S503.

In step S501, after the refrigerator is powered on, the current level state of the first signal is determined, where the first signal is a control signal of the variable frequency control board of the refrigerator, and the level state includes a high level and a low level.

Step S502, if the current level state of the first signal is high level, judging whether the communication between the communication circuit of the frequency conversion board and the communication circuit of the main control board is normal;

In step S503, if the communication between the variable frequency board communication circuit and the main control board communication circuit is abnormal, the level state of the first signal is controlled to be adjusted to a low level, so that the signal control chip in the variable frequency board communication circuit switches the received signal pin and the transmitted signal pin according to the first signal, so as to restore the communication between the variable frequency board communication circuit and the main control board communication circuit to be normal.

In the embodiment of the application, the first signal, namely the SW signal, is used for controlling the passage between the communication circuit of the frequency conversion board and the communication circuit of the main control board. Generally, in an initial state, after the refrigerator is powered on, the SW signal defaults to a high level, and when the connection between the communication circuit of the frequency conversion board and the communication circuit of the main control board is correct, the communication between the communication circuit of the frequency conversion board and the communication circuit of the main control board can be normal because the SW signal is a high level. When the wiring connection between the variable frequency board communication circuit and the main control board communication circuit is incorrect, the SW signal is high level, so that normal communication between the variable frequency board communication circuit and the main control board communication circuit is not possible. That is, when the SW signal is at a high level and normal communication is not possible between the variable frequency board communication circuit and the main control board communication circuit, it is indicated that the connection between the variable frequency board communication circuit and the main control board communication circuit is incorrect. At this time, the control adjusts the SW signal to a low level, so that the inverter board communication circuit sends the SW signal to the loop received by the main control board communication circuit, and as described above, since the SW signal is adjusted to a low level, B0 and a in the first signal control chip IC1 can be turned on, so that the 1 pin TX and the 2 pin RX at CN2 can be switched, that is, the signal sent by the inverter board communication circuit is processed by the first signal control chip IC1, and in fact, the 2 pin of CN2 has become the sending signal pin TX. Therefore, the signal sent by the frequency conversion board communication circuit can be ensured to be smoothly sent to the main control board communication circuit. In the loop that the main control board communication circuit sent to the frequency conversion board communication circuit received, because the SW signal is adjusted to the low level, B0 and A in the second signal control chip IC2 can be made to be conducted, so that 1 pin TX and 2 pin RX at CN2 can be switched, namely through the processing of the second signal control chip IC2, 1 pin of CN2 has actually become the receiving signal pin RX. Therefore, the signal sent by the main control board communication circuit can be ensured to be smoothly sent to the variable frequency board communication circuit.

In the embodiment of the application, when the communication between the communication circuit of the frequency conversion board and the communication circuit of the main control board is normal, the method comprises the following steps:

and memorizing a first state so as to enable the refrigerator to keep the first state when the refrigerator is electrified next time, wherein the first state is a level state of the first signal in a normal communication state between the variable frequency board communication circuit and the main control board communication circuit.

When the SW is at a high level, the communication between the communication circuit of the frequency conversion board and the communication circuit of the main control board is judged to be normal, and the high level state of the SW signal is memorized at the moment, so that the SW signal is directly controlled to be at a high level when the refrigerator is electrified next time, and the frequency conversion board and the main control board can be directly in a normal communication state when the refrigerator is electrified next time. Similarly, when the SW is at a low level, the communication between the communication circuit of the variable frequency board and the communication circuit of the main control board is judged to be normal, and the low level state of the SW signal is memorized at the moment so as to directly control the SW signal to be at a low level when the refrigerator is electrified next time, thereby ensuring that the communication between the communication circuit of the variable frequency board and the communication circuit of the main control board is in a normal state when the refrigerator is electrified next time.

In the embodiment of the application, when the communication between the communication circuit of the frequency conversion board and the communication circuit of the main control board is still abnormal after the ground level state of the SW signal is regulated, a communication abnormal alarm is sent out so as to remind a worker of carrying out fault investigation and maintenance.

Referring to fig. 6, fig. 6 is a flowchart of a method for controlling switching of a transmit-receive signal according to an embodiment of the present application, including but not limited to steps S601 to S60

Step S601, powering on a refrigerator;

Step S602, the SW signal is controlled to be at a default high level;

Step S603, judging whether the communication between the communication circuit of the frequency conversion board and the communication circuit of the main control board is normal;

Step S604, if the communication between the communication circuit of the frequency conversion board and the communication circuit of the main control board is normal, the current level state of the SW signal is memorized, so that the state is kept after the refrigerator is powered on next time;

step S605, if the communication between the variable frequency board communication circuit and the main control board communication circuit is abnormal, the control SW signal is adjusted to be low level;

step S606, judging whether the communication between the frequency conversion board communication circuit and the main control board communication circuit is normal or not again;

Step S607, if not, sending out abnormal communication alarm;

in step S608, if normal, the current level state of the SW signal is memorized, so that the refrigerator is kept in this state after being powered on next time.

In the embodiment of the application, based on the refrigerator variable frequency control board shown in fig. 2, under the condition that the connecting line between the variable frequency board communication circuit and the main control board communication circuit is reversely connected, the level state of the SW signal can be controlled and adjusted to ensure the communication between the variable frequency board communication circuit and the main control board communication circuit, and the level state of the SW signal under the normal condition of communication can be memorized, so that the variable frequency board communication circuit and the main control board communication circuit can be directly in the normal communication state when the refrigerator is electrified next time.

The terms "first," "second," "third," "fourth," and the like in the description of the application and in the above figures, if any, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the application described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

It should be understood that in the present application, "at least one (item)" means one or more, and "a plurality" means two or more. "and/or" for describing the association relationship of the association object, the representation may have three relationships, for example, "a and/or B" may represent: only a, only B and both a and B are present, wherein a, B may be singular or plural. The character "/" generally indicates that the context-dependent object is an "or" relationship. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). For example, at least one (one) of a, b or c may represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", wherein a, b, c may be single or plural.

The preferred embodiments of the present application have been described above with reference to the accompanying drawings, and are not thereby limiting the scope of the claims of the embodiments of the present application. Any modifications, equivalent substitutions and improvements made by those skilled in the art without departing from the scope and spirit of the embodiments of the present application shall fall within the scope of the claims of the embodiments of the present application.

Claims (7)

1. The refrigerator variable frequency control board is characterized by comprising a variable frequency board communication circuit and a main control board communication circuit;

The first signal receiving and transmitting end of the frequency conversion board communication circuit is connected with two identical signal control chips in parallel, and the signal control chips are used for switching a first receiving signal pin and a first transmitting signal pin at the first signal receiving and transmitting end;

The second signal receiving and transmitting end of the main control board communication circuit is connected with the first signal receiving and transmitting end of the variable frequency board communication circuit through three communication lines;

The first signal receiving and transmitting end comprises a first receiving signal pin, a first transmitting signal pin and a first ground wire pin;

the second signal receiving and transmitting end comprises a second receiving signal pin, a second transmitting signal pin and a second ground wire pin;

the connection mode between the first signal receiving and transmitting end and the second signal receiving and transmitting end comprises:

The first receiving signal pin is connected with the second sending signal pin, the first sending signal pin is connected with the second receiving signal pin, and the first ground wire pin is connected with the second ground wire pin;

Or the first receiving signal pin is connected with the second receiving signal pin, the first transmitting signal pin is connected with the second transmitting signal pin, and the first ground wire pin is connected with the second ground wire pin;

the two same signal control chips are a first signal control chip and a second signal control chip respectively;

the first end of the first signal control chip and the first end of the second signal control chip are connected in parallel with the first signal receiving and transmitting end;

the second end of the first signal control chip is connected with the first signal transmitting end of the frequency conversion board communication circuit, and the second end of the second signal control chip is connected with the first signal receiving end of the frequency conversion board communication circuit;

The first end of the first signal control chip is provided with a first pin, a second pin and a first grounding pin, and the second end of the first signal control chip is provided with a third pin, a fourth pin and a first power pin;

a fifth pin, a sixth pin and a second grounding pin are arranged at the first end of the second signal control chip, and a seventh pin, an eighth pin and a second power pin are arranged at the second end of the second signal control chip;

The first pin is connected with the sixth pin and is connected with the first transmitting signal pin of the first signal receiving and transmitting end;

the second pin is connected with the fifth pin and is connected with the first receiving signal pin of the first signal receiving and transmitting end;

The first grounding pin and the second grounding pin are connected and then grounded together;

The third pin is connected with the seventh pin and is connected with a control signal together;

the fourth pin is connected to the first signal transmitting end;

the eighth pin is connected to the first signal receiving end;

the first power supply pin and the second power supply pin are both connected with a positive power supply;

When the connection mode between the first signal receiving and transmitting end and the second signal receiving and transmitting end is that the first receiving signal pin is connected with the second transmitting signal pin, the first transmitting signal pin is connected with the second receiving signal pin, the first ground wire pin is connected with the second ground wire pin, the first pin of the first signal control chip is communicated with the fourth pin, and the fifth pin of the second signal control chip is communicated with the eighth pin;

When the connection mode between the first signal receiving and transmitting end and the second signal receiving and transmitting end is that the first receiving signal pin is connected with the second receiving signal pin, the first transmitting signal pin is connected with the second transmitting signal pin and the first ground wire pin is connected with the second ground wire pin, the second pin of the first signal control chip is communicated with the fourth pin, and the sixth pin of the second signal control chip is communicated with the eighth pin.

2. The variable frequency control board of refrigerator according to claim 1, wherein a first signal receiving end of the variable frequency board communication circuit is connected with a first resistance-capacitance filter circuit, and the first resistance-capacitance filter circuit comprises a first capacitor and a first resistor;

The first end of the first resistor is connected with a fourth pin of the second signal control chip, and the second end of the first resistor is connected with the first signal receiving end of the frequency conversion board communication circuit;

The first end of the first capacitor is connected with the second end of the first resistor, and the second end of the first capacitor is grounded.

3. The variable frequency control board of refrigerator according to claim 2, wherein the variable frequency board communication circuit further comprises a first triode switch circuit and a first pull-up resistor;

the first end of the first pull-up resistor is connected with the first end of the first resistor, and the second end of the first pull-up resistor is connected with an anode power supply;

The first triode switch circuit is arranged between the first signal transmitting end and the first signal control chip and comprises a second resistor, a first triode, a third resistor, a fourth resistor, a fifth resistor and a second capacitor;

the first end of the second resistor is connected with the first signal transmitting end, and the second end of the second resistor is connected with the first end of the first triode;

The second end of the first triode is connected with a positive electrode power supply, and the third end of the first triode is connected with the first end of the fourth resistor;

the first end of the third resistor is connected with the second end of the second resistor, and the second end of the third resistor is connected with the second end of the first triode;

the second end of the fourth resistor is connected with a fourth pin of the first signal control chip;

the first end of the fifth resistor and the first end of the second capacitor are connected with the second end of the fourth resistor, and the second end of the fifth resistor and the second end of the second capacitor are connected and then grounded together.

4. The variable frequency control board of refrigerator according to claim 3, wherein the main control board communication circuit comprises a second triode switch circuit, a first optocoupler, a second optocoupler and a second pull-up resistor;

The second triode switch circuit comprises a sixth resistor, a seventh resistor, a second triode and an eighth resistor;

the first end of the sixth resistor is connected with the second signal transmitting end of the main control board communication circuit, and the second end of the sixth resistor is connected with the first end of the second triode;

the second end of the second triode is connected with the first end of the eighth resistor, and the third end of the second triode is connected with a positive electrode power supply;

The first end of the seventh resistor is connected with the first end of the second triode, and the second end of the seventh resistor is connected with the third end of the second triode;

the second end of the eighth resistor is connected with the first end of the first optocoupler;

the second end of the first optical coupler is connected to the second signal sending pin of the second signal receiving and sending end, and the third end and the fourth end of the first optical coupler are grounded;

the first end of the second optical coupler is connected to the second receiving signal pin of the second signal receiving and transmitting end, the second end of the second optical coupler is connected to the second signal receiving end, and the third end and the fourth end of the second optical coupler are grounded;

the first end of the second pull-up resistor is connected with the second end of the second optocoupler, and the second end of the second pull-up resistor is connected with a positive power supply.

5. The variable frequency control board of refrigerator according to claim 4, wherein the second signal receiving end of the main control board communication circuit is connected with a second resistance-capacitance filter circuit, and the second resistance-capacitance filter circuit comprises a third capacitor and a ninth resistor;

the first end of the ninth resistor is connected with the second signal receiving end, and the second end of the ninth resistor is connected with the second end of the second optical coupler;

the first end of the third capacitor is connected with the first end of the ninth resistor, and the second end of the third capacitor is grounded.

6. A control method for switching between receiving and transmitting signals, which is executed based on the variable frequency control board of the refrigerator according to any one of claims 1 to 5, characterized in that the control method comprises:

Determining the current level state of a first signal after the refrigerator is electrified, wherein the first signal is a control signal of a variable frequency control board of the refrigerator, and the level state comprises a high level and a low level;

If the current level state of the first signal is high level, judging whether the communication between the communication circuit of the frequency conversion board and the communication circuit of the main control board is normal or not;

If the communication between the frequency conversion board communication circuit and the main control board communication circuit is abnormal, the level state of the first signal is controlled to be adjusted to be low level, so that a signal control chip in the frequency conversion board communication circuit switches between a received signal pin and a transmitted signal pin according to the first signal, and the communication between the frequency conversion board communication circuit and the main control board communication circuit is recovered to be normal.

7. The method of claim 6, wherein when communication between the inverter board communication circuit and the main board communication circuit is normal, the method comprises:

and memorizing a first state so as to enable the refrigerator to keep the first state when the refrigerator is electrified next time, wherein the first state is a level state of the first signal in a normal communication state between the variable frequency board communication circuit and the main control board communication circuit.