Power tube driving circuit and circuit driving method

Abstract

The embodiment of the invention discloses a power tube driving circuit and a circuit driving method. According to one specific embodiment, the power tube driving circuit comprises a driving power supply circuit, an overvoltage and overcurrent protection circuit, a control circuit and an optocoupler circuit, the optocoupler circuit comprises an optocoupler isolation circuit, a driving amplification circuit and a power tube, and the driving power supply circuit is connected with a power line of the overvoltage and overcurrent protection circuit; the overvoltage and overcurrent protection circuit is connected with the optical coupler isolation circuit and the driving amplification circuit through power lines. The control circuit is connected with a signal line of the optocoupler isolation circuit; the optocoupler isolation circuit is connected with a signal line of the driving amplification circuit; the driving amplification circuit is connected with a power tube signal line. According to the embodiment, the safety of the driving circuit is improved.

Description

Technical Field

[0001] The embodiments of the present disclosure relate to the technical field of driver circuits, and in particular to a power tube driving circuit and a circuit driving method. Background Art

[0002] The power device of the air conditioner compressor driver usually adopts an intelligent power module (IPM) or a compressor driver based on discrete power devices. At present, when using a compressor driver based on discrete power devices, the commonly used method is to drive the air conditioner compressor driver through a driver chip.

[0003] However, it is found in practice that when the above method is used to drive the air conditioner compressor driver, the following technical problems often occur:

[0004] The value attribute (cost) of the driver chip is relatively low, and it does not have functions such as overcurrent, strong and weak current isolation, driver short-circuit protection and reset, resulting in low safety of the driver circuit when overcurrent or overvoltage occurs again.

[0005] The above information disclosed in this Background section is only for enhancement of understanding of the background of the inventive concept and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. Summary of the invention

[0006] The content of this disclosure is used to introduce concepts in a brief form, which will be described in detail in the detailed implementation section below. The content of this disclosure is not intended to identify the key features or essential features of the technical solution claimed for protection, nor is it intended to limit the scope of the technical solution claimed for protection.

[0007] Some embodiments of the present disclosure propose a power tube driving circuit and a circuit driving method to solve one or more of the technical problems mentioned in the above background technology section.

[0008] In a first aspect, some embodiments of the present disclosure provide a power tube driving circuit, which includes: a driving power supply circuit, an overvoltage and overcurrent protection circuit, a control circuit and an optocoupler circuit, wherein the optocoupler circuit includes: an optocoupler isolation circuit, a driving amplifier circuit and a power tube, wherein the driving power supply circuit is connected to the overvoltage and overcurrent protection circuit power line to provide a power supply voltage for the power tube driving circuit; the overvoltage and overcurrent protection circuit is respectively connected to the optocoupler isolation circuit and the driving amplifier circuit power line to detect the current and voltage of the driving power supply circuit to avoid circuit failure caused by overvoltage and overcurrent; the control circuit is connected to the optocoupler isolation circuit signal line to control and detect signals; the optocoupler isolation circuit is connected to the driving amplifier circuit signal line to isolate strong and weak current signals to protect the control circuit from failure caused by strong current; the driving amplifier circuit is connected to the power tube signal line to amplify the driving signal and detect whether the power tube has an overcurrent condition.

[0009] Optionally, the power tube is an insulated gate bipolar transistor or a metal oxide semiconductor field effect transistor in the above-mentioned air-conditioning compressor driver.

[0010] Optionally, the overcurrent and overvoltage protection circuit includes: a first resistor, a second resistor, a third resistor, a fourth resistor, a first triode, a second triode, a third triode, a first voltage-stabilizing diode and a first diode; one end of the first resistor is connected to the first power supply, and the other end is respectively connected to pin 1 of the first triode, pin 2 of the second triode, pin 2 of the third triode and one end of the second resistor; the other end of the second resistor is respectively connected to pin 1 of the second triode and one end of the third resistor; the other end of the third resistor is connected to one end of the first voltage-stabilizing diode; one end of the fourth resistor is connected to the first signal ground, and the other end is respectively connected to pin 3 of the first diode, pin 3 of the second triode and pin 1 of the third triode; the other end of the first voltage-stabilizing diode is respectively connected to pin 3 of the third triode and one end of the first diode; the other end of the first diode is connected to the second power supply.

[0011] Optionally, the optocoupler circuit includes: a first optocoupler, a second optocoupler, a third optocoupler, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a first capacitor, a second capacitor, a third capacitor, a second diode, a third diode, a fourth diode, a fourth transistor, a fifth transistor, a driving chip, a second voltage stabilizing diode, an indicator light and a power tube.

[0012] Optionally, one end of the fifth resistor is connected to the microcontroller pin corresponding to the driving power tube signal, and the other end is connected to pin 1 of the above-mentioned first optocoupler; pin 2 of the above-mentioned first optocoupler is connected to the second signal ground, pin 3 is respectively connected to one end of the above-mentioned sixth resistor and the IN+ pin of the above-mentioned driving chip, and pin 4 is connected to the above-mentioned second power supply; the other end of the above-mentioned sixth resistor is connected to the first signal ground; pin 3 of the above-mentioned second optocoupler is connected to the microcontroller pin corresponding to the driving circuit alarm signal, pin 4 is connected to the second signal ground, pin 1 is connected to pin 2 of the fifth transistor, and pin 2 is connected to the cathode of the indicator light; one end of the above-mentioned twelfth resistor is connected The pin of the microcontroller corresponding to the state reset signal of the driving circuit is connected, and the other end is connected to pin 1 of the third optocoupler; pin 2 of the third optocoupler is connected to the second signal ground, pin 3 is connected to the first signal ground, and pin 4 is respectively connected to one end of the tenth resistor and one end of the first capacitor; pin 2 of the fourth transistor is respectively connected to the second power supply and one end of the seventh resistor, pin 1 is respectively connected to the other end of the seventh resistor and one end of the eighth resistor, and pin 3 is respectively connected to one end of the ninth resistor, the other end of the tenth resistor and the IN- pin of the driving chip.

[0013] Optionally, the other end of the eighth resistor is connected to the anode of the indicator light; pin 1 of the fifth transistor is respectively connected to the other end of the ninth resistor, one end of the eleventh resistor, the other end of the first capacitor, one end of the second capacitor and the anode of the second voltage-stabilizing diode, and pin 3 is connected to the first signal ground; the other end of the eleventh resistor is connected to the first signal ground; the other end of the second capacitor is connected to the first signal ground; the second power pin of the driving chip is respectively connected to the second power supply and one end of the third capacitor, the signal ground pin is connected to the first signal ground, and the output pin is respectively connected to the cathode of the second diode, one end of the thirteenth resistor and the g pin of the power tube; the anode of the second diode is respectively connected to the other end of the thirteenth resistor, the cathode of the second voltage-stabilizing diode and the anode of the third diode; the cathode of the third diode is connected to the anode of the fourth diode; the cathode of the fourth diode is connected to the c pin of the power tube; the e pin of the power tube is connected to the first signal ground; the other end of the third capacitor is connected to the first signal ground.

[0014] In a second aspect, some embodiments of the present disclosure provide a circuit driving method, the method comprising: in response to detecting an overcurrent, detecting a first voltage corresponding to a first resistor included in the overvoltage and overcurrent protection circuit; in response to the first voltage increasing to a preset voltage value, the overvoltage and overcurrent protection circuit controls the state of the first transistor to enter a saturation state, and adjusts the first transistor to a conducting state; the overvoltage and overcurrent protection circuit adjusts the voltage of pin 1 of the third transistor to a voltage corresponding to the first power supply, and adjusts the state of the third transistor to a cut-off state, wherein the output voltage corresponding to the third transistor is 0; in response to detecting that the overcurrent stops, the overvoltage and overcurrent protection circuit automatically adjusts to a normal working state.

[0015] The above-mentioned embodiments of the present disclosure have the following beneficial effects: through the power tube driving circuit of some embodiments of the present disclosure, the safety of the driving circuit is improved. Specifically, the reason for the low safety of the driving circuit is that the value attribute (cost) of the driving chip is low, and it does not have the functions of overcurrent, strong and weak current isolation, driving short circuit protection and reset, resulting in low safety of the driving circuit when overcurrent or overvoltage occurs again. Based on this, some embodiments of the power tube driving circuit disclosed in the present invention include: a driving power supply circuit, an overvoltage and overcurrent protection circuit, a control circuit and an optocoupler circuit, and the optocoupler circuit includes: an optocoupler isolation circuit, a driving amplifier circuit and a power tube, wherein the driving power supply circuit is connected to the overvoltage and overcurrent protection circuit power line to provide a power supply voltage for the power tube driving circuit; the overvoltage and overcurrent protection circuit is respectively connected to the optocoupler isolation circuit and the driving amplifier circuit power line to detect the current and voltage of the driving power supply circuit to avoid circuit failure caused by overvoltage and overcurrent; the control circuit is connected to the optocoupler isolation circuit signal line to control and detect signals; the optocoupler isolation circuit is connected to the driving amplifier circuit signal line to isolate strong and weak current signals to protect the control circuit from failure caused by strong current; the driving amplifier circuit is connected to the power tube signal line to amplify the driving signal and detect whether the power tube has an overcurrent condition. Also, by setting the overvoltage and overcurrent protection circuit, the overvoltage and overcurrent in the drive circuit can be monitored to avoid the situation where the circuit cannot be used due to overvoltage or overcurrent, and protect the circuit safety. In addition, after the overvoltage and overcurrent disappear, the circuit is reset in time to avoid the normal use of the circuit. In addition, the strong current signal and the weak current signal are isolated by the optical coupling isolation circuit to avoid the failure of the control circuit due to strong current. The safety of the drive circuit is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and other features, advantages and aspects of the embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. Throughout the accompanying drawings, the same or similar reference numerals represent the same or similar elements. It should be understood that the drawings are schematic and that components and elements are not necessarily drawn to scale.

[0017] Figure 1 is a schematic diagram of the structure of some embodiments of the power tube driving circuit according to the present disclosure;

[0018] Figure 2 is an overvoltage and overcurrent protection circuit diagram of some embodiments of the power tube driving circuit disclosed in the present invention;

[0019] Figure 3 is an optocoupler circuit diagram of some embodiments of the power tube driving circuit according to the present disclosure;

[0020] Figure 4 is a flow chart of some embodiments of the circuit driving method according to the present disclosure. DETAILED DESCRIPTION

[0021] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided to provide a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are only for exemplary purposes and are not intended to limit the scope of protection of the present disclosure.

[0022] It should also be noted that, for ease of description, only the parts related to the invention are shown in the drawings. In the absence of conflict, the embodiments and features in the embodiments of the present disclosure can be combined with each other.

[0023] It should be noted that the concepts such as "first" and "second" mentioned in the present disclosure are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0024] It should be noted that the modifications of "one" and "plurality" mentioned in the present disclosure are illustrative rather than restrictive, and those skilled in the art should understand that unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0025] The names of the messages or information exchanged between multiple devices in the embodiments of the present disclosure are only used for illustrative purposes and are not used to limit the scope of these messages or information.

[0026] The present disclosure will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0027] Figure 1 It is a schematic diagram of the structure of some embodiments of the power tube driving circuit according to the present disclosure. Figure 1 It includes a driving power supply circuit 1, an overvoltage and overcurrent protection circuit 2, a control circuit 3 and an optocoupler circuit. The optocoupler circuit includes an optocoupler isolation circuit 4, a driving amplifier circuit 5 and a power tube 6.

[0028] Figure 2 It is an overvoltage and overcurrent protection circuit diagram of some embodiments of the power tube driving circuit according to the present disclosure. Figure 2 It includes a first power supply VDD1, a second power supply VDD, a first signal ground GND, a first resistor R11, a second resistor R12, a third resistor R13, a fourth resistor R14, a first transistor Q11, a second transistor Q12, a third transistor Q13, a first voltage regulator diode ZD11 and a first diode D11.

[0029] Figure 3 1 is an optocoupler circuit diagram of some embodiments of the power tube driving circuit according to the present disclosure. Figure 3 It includes a first power supply VDD1, a second power supply VDD, a first signal ground GND, a second signal ground GND_L, a first optocoupler U21, a second optocoupler U22, a third optocoupler U23, a fifth resistor R21, a sixth resistor R22, a seventh resistor R23, an eighth resistor R24, a ninth resistor R25, a tenth resistor R26, an eleventh resistor R27, a twelfth resistor R28, a thirteenth resistor R29, a first capacitor C21, a second capacitor C22, a third capacitor C23, a second diode D21, a third diode D22, a fourth diode D23, a fourth transistor Q21, a fifth transistor Q22, a driving chip U24, a second voltage stabilizing diode ZD21, an indicator light LED21 and a power tube Q23.

[0030] In some embodiments, the driving power supply circuit 1 is connected to the power supply line of the overvoltage and overcurrent protection circuit 2 to provide power supply voltage for the power tube driving circuit. The power supply line between the driving power supply circuit 1 and the overvoltage and overcurrent protection circuit 2 can be a VCC (Volt Current Condenser) 1 power line. The overvoltage and overcurrent protection circuit 2 is respectively connected to the power supply lines of the optocoupler isolation circuit 4 and the driving amplifier circuit 5 to detect the current and voltage of the driving power supply circuit 1 to avoid circuit failure caused by overvoltage and overcurrent. The power line between the overvoltage and overcurrent protection circuit 2 and the optocoupler isolation circuit 4 and the driving amplifier circuit 5 is a VCC2 power line. The control circuit 3 is connected to the signal line of the optocoupler isolation circuit 4 to control and detect signals. The signal lines between the control circuit 3 and the optocoupler isolation circuit 4 include: PWM1 signal line, RST1 signal line and STA1 signal line. The optocoupler isolation circuit 4 is connected to the signal line of the driving amplifier circuit 5 to isolate strong and weak current signals and protect the control circuit 3 from failure due to strong current. Among them, the signal lines between the above-mentioned optocoupler isolation circuit 4 and the above-mentioned drive amplifier circuit 5 are PWM2 signal line, RST2 signal line and STA2 signal line. The above-mentioned drive amplifier circuit 5 is connected to the above-mentioned power tube 6 signal line, and is used to amplify the drive signal and detect whether the above-mentioned power tube 6 has an overcurrent condition. Among them, the signal lines between the above-mentioned drive amplifier circuit 5 and the above-mentioned power tube 6 are DESAT (de-saturation) signal line and PWM3 signal line. Here, the above-mentioned PWM1 signal line, PWM2 signal line and PWM3 signal line are signal lines for driving power tube signals, the above-mentioned RST1 signal line and RST2 signal line are signal lines for driving circuit state reset signals, and the above-mentioned STA1 signal line and the above-mentioned STA2 signal line are signal lines for driving circuit alarm signals.

[0031] Optionally, the power tube 6 is an insulated gate bipolar transistor or a metal oxide semiconductor field effect transistor in the air-conditioning compressor driver.

[0032] Optionally, one end of the first resistor R11 is connected to the first power supply VDD1, and the other end is respectively connected to pin 1 of the first transistor Q11, pin 2 of the second transistor Q12, pin 2 of the third transistor Q13, and one end of the second resistor R12. The first power supply VDD1 may be the power supply provided by the drive power supply circuit 1. The other end of the second resistor R12 is respectively connected to pin 1 of the second transistor Q12 and one end of the third resistor R13. The other end of the third resistor R13 is connected to one end of the first voltage zener diode ZD11. One end of the fourth resistor R14 is connected to the first signal ground GND, and the other end is respectively connected to pin 3 of the first diode D11, pin 3 of the second transistor Q12, and pin 1 of the third transistor Q13. Among them, the first signal ground GND may be a strong electric signal ground. The other end of the first voltage zener diode ZD11 is respectively connected to pin 3 of the third transistor Q13 and one end of the first diode D11. The other end of the first diode D11 is connected to a second power source VDD. The second power source VDD may be a power source converted from the first power source VDD1 by a transistor and a diode, and the second power source VDD is used to supply power to the driving chip U24.

[0033] Optionally, one end of the fifth resistor R11 is connected to the microcontroller pin corresponding to the driving power tube signal, and the other end is connected to pin 1 of the first optocoupler U21. Pin 2 of the first optocoupler U21 is connected to the second signal ground GND_L, pin 3 is respectively connected to one end of the sixth resistor R22 and the IN+ pin of the driving chip U24, and pin 4 is connected to the second power supply VDD. The other end of the sixth resistor R22 is connected to the first signal ground GND. Pin 3 of the second optocoupler U22 is connected to the microcontroller pin corresponding to the driving circuit alarm signal, pin 4 is connected to the second signal ground GND_L, pin 1 is connected to pin 2 of the fifth transistor Q22, and pin 2 is connected to the cathode of the indicator LED21. Among them, the second signal ground GND_L can be a weak current signal ground. One end of the twelfth resistor R28 is connected to the microcontroller pin corresponding to the driving circuit state reset signal, and the other end is connected to pin 1 of the third optocoupler U23. Pin 2 of the third optical coupler U23 is connected to the second signal ground GND_L, pin 3 is connected to the first signal ground GND, and pin 4 is respectively connected to one end of the tenth resistor R26 and one end of the first capacitor C21. Pin 2 of the fourth transistor Q21 is respectively connected to the second power supply VDD and one end of the seventh resistor R23, pin 1 is respectively connected to the other end of the seventh resistor R23 and one end of the eighth resistor R24, and pin 3 is respectively connected to one end of the ninth resistor R25, the other end of the tenth resistor R26, and the IN-pin of the driving chip U24.

[0034] Optionally, the other end of the eighth resistor R24 ​​is connected to the anode of the indicator light LED21 .

[0035] Pin 1 of the fifth transistor Q22 is respectively connected to the other end of the ninth resistor R25, one end of the eleventh resistor R27, the other end of the first capacitor C21, one end of the second capacitor C22 and the anode of the second voltage stabilizing diode ZD21, and pin 3 is connected to the first signal ground GND; the other end of the eleventh resistor R27 is connected to the first signal ground GND; the other end of the second capacitor C22 is connected to the first signal ground GND; the second power supply pin of the driving chip U24 is respectively connected to the second power supply VDD and one end of the third capacitor C23, the signal ground pin is connected to the first signal ground GND, and the output pin They are respectively connected to the cathode of the above-mentioned second diode D21, one end of the above-mentioned thirteenth resistor R29 and the g pin of the above-mentioned power tube Q23; the anode of the above-mentioned second diode D21 is respectively connected to the other end of the above-mentioned thirteenth resistor R29, the cathode of the above-mentioned second voltage-stabilizing diode ZD21 and the anode of the above-mentioned third diode D22; the cathode of the above-mentioned third diode D22 is connected to the anode of the above-mentioned fourth diode D23; the cathode of the above-mentioned fourth diode D23 is connected to the c pin of the above-mentioned power tube Q23; the e pin of the above-mentioned power tube Q23 is connected to the first signal ground GND; the other end of the above-mentioned third capacitor C23 is connected to the first signal ground GND.

[0036] The above-mentioned embodiments of the present disclosure have the following beneficial effects: through the power tube driving circuit of some embodiments of the present disclosure, the safety of the driving circuit is improved. Specifically, the reason for the low safety of the driving circuit is that the value attribute (cost) of the driving chip is low, and it does not have the functions of overcurrent, strong and weak current isolation, driving short circuit protection and reset, resulting in low safety of the driving circuit when overcurrent or overvoltage occurs again. Based on this, some embodiments of the power tube driving circuit disclosed in the present invention include: a driving power supply circuit, an overvoltage and overcurrent protection circuit, a control circuit and an optocoupler circuit, and the optocoupler circuit includes: an optocoupler isolation circuit, a driving amplifier circuit and a power tube, wherein the driving power supply circuit is connected to the overvoltage and overcurrent protection circuit power line to provide a power supply voltage for the power tube driving circuit; the overvoltage and overcurrent protection circuit is respectively connected to the optocoupler isolation circuit and the driving amplifier circuit power line to detect the current and voltage of the driving power supply circuit to avoid circuit failure caused by overvoltage and overcurrent; the control circuit is connected to the optocoupler isolation circuit signal line to control and detect signals; the optocoupler isolation circuit is connected to the driving amplifier circuit signal line to isolate strong and weak current signals to protect the control circuit from failure caused by strong current; the driving amplifier circuit is connected to the power tube signal line to amplify the driving signal and detect whether the power tube has an overcurrent condition. Also, by setting the overvoltage and overcurrent protection circuit, the overvoltage and overcurrent in the drive circuit can be monitored to avoid the situation where the circuit cannot be used due to overvoltage or overcurrent, and protect the circuit safety. In addition, after the overvoltage and overcurrent disappear, the circuit is reset in time to avoid the normal use of the circuit. In addition, the strong current signal and the weak current signal are isolated by the optical coupling isolation circuit to avoid the failure of the control circuit due to strong current. The safety of the drive circuit is improved.

[0037] Further references Figure 4 , shows a process 400 of some embodiments of the circuit driving method according to the present disclosure. The circuit driving method is applied to Figure 1 The power tube driving circuit shown includes the following steps:

[0038] Step 401: In response to detecting an overcurrent, a control circuit detects a first voltage corresponding to a first resistor included in an overvoltage and overcurrent protection circuit.

[0039] In some embodiments, in response to detecting an overcurrent, the overvoltage and overcurrent protection circuit may detect a first voltage corresponding to the first resistor included therein, wherein the first voltage may be a voltage borne by the first resistor.

[0040] Step 402: In response to the first voltage increasing to a preset voltage value, the overvoltage and overcurrent protection circuit adjusts the state of the first transistor to a conducting state.

[0041] In some embodiments, in response to the first voltage increasing to a preset voltage value, the overvoltage and overcurrent protection circuit adjusts the first transistor to a conducting state. Before adjusting the state of the first transistor, the first transistor is in a saturated state. The preset voltage value may be a preset maximum threshold value of a voltage that the first resistor can withstand. For example, the preset voltage value may be 0.7V.

[0042] Step 403, the overvoltage and overcurrent protection circuit adjusts the voltage of pin 1 of the third transistor to the voltage corresponding to the first power supply, and adjusts the state of the third transistor to the cut-off state, wherein the output voltage corresponding to the third transistor is 0.

[0043] In some embodiments, the overvoltage and overcurrent protection circuit adjusts the voltage of pin 1 of the third transistor to the voltage corresponding to the first power supply, and adjusts the state of the third transistor to the cut-off state. The initial voltage of pin 1 of the third transistor may be 0V. At this time, the state of the third transistor is adjusted from the saturation state to the cut-off state, and the output voltage of the third transistor is 0V. Here, the overvoltage and overcurrent protection circuit enters the overcurrent protection state.

[0044] Step 404: in response to detecting that the overcurrent stops, the overvoltage and overcurrent protection circuit automatically adjusts to a normal working state.

[0045] In some embodiments, in response to detecting that the overcurrent stops, the overvoltage and overcurrent protection circuit can automatically adjust to a normal working state, wherein the normal working state can be a circuit state when no overcurrent or overvoltage occurs.

[0046] Optionally, after step 404, the following steps are further included:

[0047] In the first step, in response to detecting an overvoltage, and the overvoltage is greater than a preset voltage threshold, the overvoltage and overcurrent protection circuit controls the overvoltage to pass through the second resistor, the third resistor and the first Zener diode to form a loop, and the first Zener diode is turned on.

[0048] In some embodiments, in response to detecting an overvoltage, and the overvoltage is greater than a preset voltage threshold, the overvoltage passes through the second resistor, the third resistor, and the first voltage zener diode to form a loop, and the first voltage zener diode is turned on. The preset voltage threshold may be a pre-set voltage threshold.

[0049] In the second step, the overvoltage and overcurrent protection circuit adjusts the state of the second transistor to a saturation state, and adjusts the state of the third transistor to a cut-off state, wherein the output voltage of the third transistor is 0.

[0050] In some embodiments, the overvoltage and overcurrent protection circuit adjusts the state of the second triode to a saturation state, and adjusts the state of the third triode to a cut-off state, wherein the output voltage of the third triode is 0. The state of the second triode enters a saturation state from a cut-off state, and the state of the third triode enters a cut-off state from a saturation state.

[0051] In the third step, in response to detecting that the overvoltage stops, the overvoltage and overcurrent protection circuit automatically adjusts to a normal working state.

[0052] In some embodiments, in response to detecting that the overvoltage stops, the overvoltage and overcurrent protection circuit automatically adjusts to a normal working state.

[0053] Optionally, after step 404, the following steps are further included:

[0054] In the first step, in response to the state of the above-mentioned optocoupler circuit being a normal working state and the above-mentioned driving power tube signal being a high-level signal, the above-mentioned optocoupler circuit adjusts the diode included in the first optocoupler to a conducting state.

[0055] In some embodiments, in response to the state of the optocoupler circuit being in a normal working state and the driving power tube signal being a high level signal, the optocoupler circuit adjusts the diode included in the first optocoupler to a conducting state. The driving power tube signal is a signal in the PWM1 signal line.

[0056] In the second step, the optocoupler circuit controls the pin 3 of the first optocoupler to output a high level, and adjusts the states of the fourth transistor and the fifth transistor to a cut-off state.

[0057] In some embodiments, the optocoupler circuit controls the pin 3 of the first optocoupler to output a high level, and adjusts the states of the fourth transistor and the fifth transistor to a cut-off state.

[0058] In the third step, the above-mentioned optocoupler circuit controls the IN+ pin of the above-mentioned driver chip to correspond to a high level, the IN- pin to correspond to a low level, and the output pin outputs a high level.

[0059] In some embodiments, the optocoupler circuit controls the IN+ pin of the driver chip to correspond to a high level, the IN- pin to correspond to a low level, and the output pin to output a high level.

[0060] In the fourth step, the optocoupler circuit controls the power tube to be turned on, wherein the voltage difference between the c pin and the e pin included in the power tube is within a preset voltage difference range.

[0061] In some embodiments, the optical coupling circuit controls the power tube to be turned on, wherein the voltage difference between the c pin and the e pin included in the power tube is within a preset voltage difference range. The preset voltage difference range may be a preset voltage difference range between the voltages corresponding to the c pin and the e pin. For example, the preset voltage difference range may be (0V, 0.1V).

[0062] In the fifth step, the optical coupling circuit controls the thirteenth resistor, the third diode and the fourth diode to form a loop, and adjusts the state of the second voltage regulator diode to a cut-off state.

[0063] In some embodiments, the optocoupler circuit controls the thirteenth resistor, the third diode and the fourth diode to form a loop, and adjusts the state of the second voltage regulator diode to a cut-off state.

[0064] In the process of adopting technical solutions to solve the technical problems raised by the background technology, the following technical problems often occur: when using a dedicated multi-protection function and high-reliability power tube driver chip, when the gate source of the power tube breaks down and shorts, it will cause the driving voltage to drop, affecting the normal operation of other circuits and the normal operation of the core control circuit. In the face of the above technical problems, combined with the current technical status, it can be decided to adopt the following solutions:

[0065] Optionally, after the fifth step, the following steps are further included:

[0066] In the sixth step, in response to overcurrent being detected in the optocoupler circuit and the drive power tube signal being a high level signal, the optocoupler circuit controls the drive chip to output a high level.

[0067] In some embodiments, in response to overcurrent being detected in the optocoupler circuit and the driving power tube signal being a high level signal, the optocoupler circuit controls the driving chip to output a high level.

[0068] In the seventh step, in response to the overcurrent in the power tube, the optocoupler circuit adjusts the state of the power tube from a saturation state to an amplification state.

[0069] In some embodiments, in response to an overcurrent in the power tube, the optocoupler circuit adjusts the state of the power tube from a saturation state to an amplification state.

[0070] In the eighth step, in response to the voltage difference being greater than a preset voltage difference threshold, the optocoupler circuit controls the second voltage regulator diode to be turned on, and controls the first capacitor and the second capacitor to start charging.

[0071] In some embodiments, in response to the voltage difference being greater than a preset voltage difference threshold, the optocoupler circuit controls the second voltage zener diode to conduct, and controls the first capacitor and the second capacitor to start charging. The preset voltage difference threshold may be a threshold of a voltage that the second voltage zener diode can withstand.

[0072] In the ninth step, the optocoupler circuit controls the fifth transistor to be adjusted from the cut-off state to the saturation state, and adjusts the indicator light to a normally-on state, wherein the state of the second optocoupler is the on state.

[0073] In some embodiments, the optocoupler circuit controls the fifth transistor to be adjusted from a cut-off state to a saturation state, and adjusts the indicator light to a constantly on state, wherein the second optocoupler is in a conducting state.

[0074] In the tenth step, the optocoupler circuit controls the microcontroller pin corresponding to the alarm signal of the driving circuit to be connected to the signal ground, and the state of the fourth transistor is adjusted from the cut-off state to the saturation state.

[0075] In some embodiments, the optocoupler circuit controls the microcontroller pin corresponding to the alarm signal of the driving circuit to be connected to the signal ground, and the state of the fourth transistor is adjusted from the cut-off state to the saturation state.

[0076] In the eleventh step, the optocoupler circuit adjusts the low level corresponding to the IN-pin of the driver chip to a high level, adjusts the high level corresponding to the output pin to a low level, and controls the fourth transistor and the fifth transistor to form an interlock, wherein the power tube is in the off state.

[0077] In some embodiments, the optocoupler circuit adjusts the low level corresponding to the IN-pin of the driver chip to a high level, adjusts the high level corresponding to the output pin to a low level, and controls the fourth transistor and the fifth transistor to form an interlock, wherein the power tube is in the off state.

[0078] In the twelfth step, in response to receiving the circuit recovery signal sent by the target terminal, the optocoupler circuit sets the driving circuit state recovery signal to high.

[0079] In some embodiments, in response to receiving a circuit recovery signal sent by a target terminal, the optocoupler circuit sets the driving circuit state recovery signal high. The circuit recovery signal may be a signal used to indicate that the circuit is recovering normally. The target terminal may be a terminal connected to the driving circuit by wire or wirelessly.

[0080] In the thirteenth step, the optical coupler circuit discharges the charges in the first capacitor and the second capacitor through the third optical coupler.

[0081] In some embodiments, the optocoupler circuit discharges the charges in the first capacitor and the second capacitor through the third optocoupler.

[0082] In the fourteenth step, the optocoupler circuit pulls down the voltage of pin 1 of the fifth transistor, and adjusts the fourth transistor and the fifth transistor to a cut-off state.

[0083] In some embodiments, the optocoupler circuit pulls down the voltage of pin 1 of the fifth transistor, and adjusts the fourth transistor and the fifth transistor to a cut-off state.

[0084] The relevant contents in the above-mentioned steps 6 to 14 are an inventive point of the present disclosure, which solves the technical problem 2 mentioned in the background technology: "When using a dedicated multi-protection function and high-reliability power tube driver chip, when the gate source of the power tube breaks down and shorts, it will cause the driving voltage to drop, affecting the normal operation of other circuits and the normal operation of the core control circuit." The factors that cause the driving circuit to fail to work properly and the core control circuit to fail to work properly are often as follows: When using a dedicated multi-protection function and high-reliability power tube driver chip, when the gate source of the power tube breaks down and shorts, it will cause the driving voltage to drop, affecting the normal operation of other circuits and the normal operation of the core control circuit. If the above-mentioned factors are solved, the effect of avoiding the driving circuit from failing to work properly and the core control circuit from failing to work properly can be achieved. In order to achieve this effect, first, in response to the detection of overcurrent in the above-mentioned optocoupler circuit, and the above-mentioned driving power tube signal is a high-level signal, the above-mentioned driver chip outputs a high level; in response to the overcurrent in the above-mentioned power tube, the state of the above-mentioned power tube is adjusted from a saturated state to an amplified state; in response to the above-mentioned voltage difference being greater than the preset voltage difference threshold, the above-mentioned second voltage regulator diode is turned on, and the above-mentioned first capacitor and the above-mentioned second capacitor begin to charge. Thus, the excess charge in the circuit can be stored in the capacitor. Second, the fifth transistor is adjusted from the cut-off state to the saturation state, the second optical coupler is turned on, and the indicator light is adjusted to the normally on state; the microcontroller pin corresponding to the drive circuit alarm signal is connected to the signal ground, and the state of the fourth transistor is adjusted from the cut-off state to the saturation state. Thus, an alarm can be given for overcurrent conditions. Third, the low level corresponding to the IN-pin of the drive chip is adjusted to a high level, the high level corresponding to the output pin is adjusted to a low level, the power tube is turned off, and the fourth transistor and the fifth transistor are interlocked. Thus, the drive circuit can be protected to avoid the breakdown of the gate source of the power tube due to overcurrent, thereby avoiding affecting the normal operation of other circuits. Fourth, in response to receiving the circuit recovery signal sent by the target terminal, the drive circuit state recovery signal is set high; the charge in the first capacitor and the second capacitor is discharged through the third optical coupler; the voltage of the 1-pin of the fifth transistor is pulled down, and the fourth transistor and the fifth transistor are adjusted to the cut-off state. Thus, the driving circuit can be reset, thereby preventing the driving circuit from failing to work properly and preventing the core control circuit from failing to work properly.

[0085] The above-mentioned various embodiments of the present disclosure have the following beneficial effects: through the circuit driving method of some embodiments of the present disclosure, the safety of the driving circuit is improved. Specifically, the reason for the low safety of the driving circuit is that the value attribute (cost) of the driving chip is low, and it does not have the functions of overcurrent, strong and weak electrical isolation, driving short circuit protection and reset, resulting in low safety of the driving circuit when overcurrent or overvoltage occurs again. Based on this, the circuit driving method of some embodiments of the present disclosure, first, in response to the detection of overcurrent, detects the first voltage corresponding to the first resistor included in the overvoltage and overcurrent protection circuit. Thus, the voltage borne by the first resistor can be detected. Secondly, in response to the increase of the first voltage to a preset voltage value, the state of the first transistor enters a saturation state, and the first transistor is adjusted to a conducting state. Thus, when the voltage borne by the first resistor reaches the preset voltage value, the first transistor is enabled. Then, the voltage of the 1st pin of the third transistor is changed to the voltage corresponding to the first power supply, and the state of the third transistor is adjusted to a cut-off state, and the corresponding output voltage is adjusted to 0. Thus, the third triode can be disconnected, and the output voltage of the third triode can be adjusted to 0, thereby avoiding the problem of circuit damage caused by excessive current. Finally, in response to detecting that the overcurrent stops, the overvoltage and overcurrent protection circuit is adjusted to a normal working state. Thus, the circuit can be reset after the current returns to normal. Also, because the circuit is protected by the overvoltage and overcurrent protection circuit, damage to the circuit caused by overvoltage and overcurrent is avoided, and the safety of the drive circuit is improved.

[0086] The above descriptions are only some preferred embodiments of the present disclosure and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the embodiments of the present disclosure is not limited to the technical solutions formed by a specific combination of the above-mentioned technical features, but should also cover other technical solutions formed by any combination of the above-mentioned technical features or their equivalent features without departing from the above-mentioned inventive concept. For example, the above-mentioned features are replaced with the technical features with similar functions disclosed in the embodiments of the present disclosure (but not limited to) and the technical solutions formed.

Claims

1. A power tube drive circuit, suitable for an air conditioner compressor driver, the power tube drive circuit comprising: A driving power supply circuit, an overvoltage and overcurrent protection circuit, a control circuit and an optocoupler circuit, wherein the optocoupler circuit includes an optocoupler isolation circuit, a driving amplifier circuit and a power tube, wherein: The driving power supply circuit is connected to the power line of the overvoltage and overcurrent protection circuit, and is used to provide a power supply voltage for the power tube driving circuit; The overvoltage and overcurrent protection circuit is connected to the optical coupling isolation circuit and the power line of the driving amplifier circuit respectively, and is used to detect the current and voltage of the driving power supply circuit to avoid circuit failure caused by overvoltage and overcurrent; The control circuit is connected to the signal line of the optocoupler isolation circuit and is used to control and detect signals; The optical coupling isolation circuit is connected to the signal line of the driving amplifier circuit, and is used to isolate strong current and weak current signals, so as to protect the control circuit from failure caused by strong current; The driving amplifier circuit is connected to the power tube signal line and is used to amplify the driving signal and detect whether the power tube has an overcurrent condition.

2. The power tube driving circuit according to claim 1, wherein: The power tube is an insulated gate bipolar transistor or a metal oxide semiconductor field effect transistor in the air conditioner compressor driver.

3. The power tube driving circuit according to claim 1, wherein: The overcurrent and overvoltage protection circuit comprises: a first resistor, a second resistor, a third resistor, a fourth resistor, a first triode, a second triode, a third triode, a first voltage stabilizing diode and a first diode; One end of the first resistor is connected to the first power supply, and the other end is respectively connected to pin 1 of the first transistor, pin 2 of the second transistor, pin 2 of the third transistor and one end of the second resistor; The other end of the second resistor is connected to pin 1 of the second transistor and one end of the third resistor respectively; The other end of the third resistor is connected to one end of the first voltage stabilizing diode; One end of the fourth resistor is connected to the first signal ground, and the other end is respectively connected to pin 3 of the first diode, pin 3 of the second transistor, and pin 1 of the third transistor; The other end of the first voltage stabilizing diode is connected to the 3rd pin of the third transistor and one end of the first diode respectively; The other end of the first diode is connected to the second power supply.

4. The power tube driving circuit according to claim 3, wherein: The optocoupler circuit includes: a first optocoupler, a second optocoupler, a third optocoupler, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a first capacitor, a fourth transistor, a fifth transistor, a driving chip and an indicator light. One end of the fifth resistor is connected to the microcontroller pin corresponding to the driving power tube signal, and the other end is connected to pin 1 of the first optical coupler; Pin 2 of the first optical coupler is connected to the second signal ground, pin 3 is respectively connected to one end of the sixth resistor and the IN+ pin of the driver chip, and pin 4 is connected to the second power supply; The other end of the sixth resistor is connected to the first signal ground; Pin 3 of the second optical coupler is connected to the microcontroller pin corresponding to the alarm signal of the driving circuit, pin 4 is connected to the second signal ground, pin 1 is connected to pin 2 of the fifth transistor, and pin 2 is connected to the cathode of the indicator light; One end of the twelfth resistor is connected to the microcontroller pin corresponding to the driving circuit state reset signal, and the other end is connected to pin 1 of the third optical coupler; Pin 2 of the third optical coupler is connected to the second signal ground, pin 3 is connected to the first signal ground, and pin 4 is respectively connected to one end of the tenth resistor and one end of the first capacitor; Pin 2 of the fourth transistor is respectively connected to the second power supply and one end of the seventh resistor, pin 1 is respectively connected to the other end of the seventh resistor and one end of the eighth resistor, and pin 3 is respectively connected to one end of the ninth resistor, the other end of the tenth resistor and the IN-pin of the driving chip.

5. The power tube driving circuit according to claim 4, wherein: The optical coupling circuit further includes: a twelfth resistor, a thirteenth resistor, a second capacitor, a third capacitor, a second diode, a third diode, a fourth diode, a second voltage regulator diode and a power tube. The other end of the eighth resistor is connected to the anode of the indicator light; Pin 1 of the fifth transistor is respectively connected to the other end of the ninth resistor, one end of the eleventh resistor, the other end of the first capacitor, one end of the second capacitor and the anode of the second voltage stabilizing diode, and pin 3 is connected to the first signal ground; The other end of the eleventh resistor is connected to the first signal ground; The other end of the second capacitor is connected to the first signal ground; The second power pin of the driving chip is respectively connected to the second power supply and one end of the third capacitor, the signal ground pin is connected to the first signal ground, and the output pin is respectively connected to the cathode of the second diode, one end of the thirteenth resistor and the g pin of the power tube; The anode of the second diode is respectively connected to the other end of the thirteenth resistor, the cathode of the second voltage stabilizing diode and the anode of the third diode; The cathode of the third diode is connected to the anode of the fourth diode; The cathode of the fourth diode is connected to the C pin of the power tube; The e pin of the power tube is connected to the first signal ground; The other end of the third capacitor is connected to the first signal ground.

6. A circuit driving method, applied to the power tube driving circuit according to any one of claims 1 to 5, the power tube driving circuit comprising: A driving power supply circuit, an overvoltage and overcurrent protection circuit, a control circuit and an optocoupler circuit, wherein the optocoupler circuit includes an optocoupler isolation circuit, a driving amplifier circuit and a power tube, and the method includes: In response to detecting an overcurrent, the control circuit detects a first voltage corresponding to a first resistor included in the overvoltage and overcurrent protection circuit; In response to the first voltage increasing to a preset voltage value, the overvoltage and overcurrent protection circuit adjusts the state of the first transistor to a conducting state, wherein before adjusting the state of the first transistor, the first transistor is in a saturated state; The overvoltage and overcurrent protection circuit adjusts the voltage of pin 1 of the third transistor to the voltage corresponding to the first power supply, and adjusts the state of the third transistor to the cut-off state, wherein the output voltage corresponding to the third transistor is 0; In response to detecting that the overcurrent stops, the overvoltage and overcurrent protection circuit automatically adjusts to a normal working state.

7. The circuit driving method according to claim 6, wherein: The method further comprises: In response to detecting an overvoltage, and the overvoltage is greater than a preset voltage threshold, the overvoltage and overcurrent protection circuit passes the overvoltage through the second resistor, the third resistor and the first voltage zener diode to form a loop, and the first voltage zener diode is turned on; The control circuit controls the overvoltage and overcurrent protection circuit to adjust the state of the second transistor to a saturation state, and adjusts the state of the third transistor to a cut-off state, wherein the output voltage of the third transistor is 0; In response to detecting that the overvoltage stops, the overvoltage and overcurrent protection circuit automatically adjusts to a normal working state.

8. The circuit driving method according to claim 6, wherein: The method further comprises: In response to the state of the optocoupler circuit being a normal working state and the driving power tube signal being a high level signal, the optocoupler circuit adjusts the diode included in the first optocoupler to a conducting state; The optocoupler circuit controls the pin 3 of the first optocoupler to output a high level, and adjusts the states of the fourth transistor and the fifth transistor to a cut-off state; The optocoupler circuit controls the IN+ pin of the driver chip to correspond to a high level, the IN- pin to correspond to a low level, and the output pin to output a high level; The optocoupler circuit controls the power tube to be turned on, wherein the voltage difference between the c pin and the e pin included in the power tube is within a preset voltage difference range; The optocoupler circuit controls the thirteenth resistor, the third diode and the fourth diode to form a loop, and adjusts the state of the second voltage regulator diode to a cut-off state.

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