Proportional solenoid valve drive circuit and system

Abstract

This application discloses a proportional solenoid valve drive circuit and system, relating to the field of drive circuit technology. The system includes: a sampling module detecting the drive current of the proportional solenoid valve and outputting a first sampling voltage; a comparison module comparing the first sampling voltage with a first preset voltage and outputting an adjustment signal; a trigger module outputting a trigger signal based on the output voltage of a trigger power supply and the adjustment signal; a power drive module outputting a drive signal based on the trigger signal; and a power module adjusting the drive current output from the drive power supply to the proportional solenoid valve based on the drive signal, so that the proportional solenoid valve operates in constant current mode. This application solves the technical problem of existing proportional solenoid valve drive methods requiring different control programs to control different types of proportional solenoid valves, resulting in low applicability, and improves the applicability of proportional solenoid valve drive circuits.

Description

Technical Field

[0001] This application relates to the field of drive circuit technology, and in particular to a proportional solenoid valve drive circuit and system. Background Technology

[0002] In related technologies, a constant current drive proportional solenoid valve is achieved by using an MCU (Microcontroller Unit) to output a PWM (Pulse Width Modulation) signal based on the feedback voltage to control the switching state of a MOS (Metal-Oxide-Semiconductor Field-Effect Transistor).

[0003] However, in the existing proportional solenoid valve driving method, constant current driving is implemented through the software layer of the MCU. Different control programs need to be written when controlling different types of proportional solenoid valves, which has low applicability. Summary of the Invention

[0004] The main objective of this application is to provide a proportional solenoid valve drive circuit and system, which aims to solve the technical problem that existing proportional solenoid valve drive methods require different control programs to control different types of proportional solenoid valves, resulting in low applicability.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] In a first aspect, this application provides a proportional solenoid valve drive circuit, the proportional solenoid valve drive circuit comprising:

[0007] The sampling module, connected to the proportional solenoid valve, is used to detect the drive current of the proportional solenoid valve and output the first sampling voltage.

[0008] The comparison module, connected to the sampling module, is used to compare the magnitude of the first sampled voltage with the first preset voltage and output an adjustment signal.

[0009] The trigger module is connected to the trigger power supply and the comparator module respectively, and is used to output a trigger signal according to the output voltage of the trigger power supply and the adjustment signal;

[0010] The power drive module, connected to the trigger module, is used to output a drive signal according to the trigger signal;

[0011] The power module is connected to the drive power supply, the power drive module, and the proportional solenoid valve respectively. It is used to adjust the drive current output from the drive power supply to the proportional solenoid valve according to the drive signal, so that the proportional solenoid valve operates in constant current mode.

[0012] Optionally, the triggering module includes:

[0013] The trigger, connected to the trigger power supply and the comparator module respectively, is used to output the first trigger signal according to the adjustment signal and the output voltage;

[0014] An inverter, connected to the trigger power supply and the comparator module, is used to invert the regulation signal and the output voltage to output a second trigger signal.

[0015] The power drive module is connected to a trigger and an inverter respectively, and is used to output a drive signal according to the first trigger signal and the second trigger signal.

[0016] Optionally, the proportional solenoid valve drive circuit also includes;

[0017] The operational amplifier module, connected to the sampling module, is used to amplify the first sampled voltage to obtain the amplified sampled voltage;

[0018] The comparison module, connected to the operational amplifier module, is used to compare the amplified sampled voltage with the first preset voltage and output an adjustment signal.

[0019] Optionally, the power module includes a first power device and a second power device;

[0020] The control terminal of the first power device is connected to the power drive module, the input terminal of the first power device is connected to the drive power supply, the output terminal of the first power device is connected to the proportional solenoid valve and the input terminal of the second power device respectively, the control terminal of the second power device is connected to the power drive module, and the output terminal of the second power device is grounded.

[0021] Optionally, the proportional solenoid valve drive circuit further includes:

[0022] The short-circuit protection module, connected to the trigger module, is used to pull down the trigger signal and control the power drive module to stop outputting drive signals when a short-circuit fault occurs in the proportional solenoid valve.

[0023] Optionally, the short-circuit protection module includes:

[0024] The sampling unit, connected to the drive power supply, is used to collect the output current of the drive power supply and output a second sampling voltage;

[0025] The comparison unit, connected to the sampling unit, is used to output a self-locking control signal when the second sampled voltage is greater than the second preset voltage;

[0026] The self-locking unit, connected to the comparison unit and the trigger module, is used to self-lock according to the self-locking control signal, pull down the trigger signal, and control the power drive module to stop outputting drive signals.

[0027] Optionally, the short-circuit protection module also includes:

[0028] The control unit is used to output a reset control signal;

[0029] The reset unit, connected to the control unit and the self-locking unit, is used to control the self-locking unit to unlock according to the reset control signal.

[0030] Optionally, the self-locking unit includes a first switching device, a second switching device, a first diode, and a second diode;

[0031] The control terminal of the first switching device is connected to the comparison unit, one end of the first resistor, one end of the first capacitor, the output terminal of the second switching device, and the reset unit. The output terminal of the first switching device, the other end of the first resistor, and the other end of the first capacitor are all grounded. The input terminal of the first switching device is connected to the control terminal of the second switching device, one end of the third resistor, the cathode of the first diode, the cathode of the second diode, and the control unit. The anodes of the first diode and the second diode are both connected to the trigger module. The other end of the third resistor is connected to the input terminal of the second switching device and the power supply.

[0032] Optionally, the reset unit includes a third switching device;

[0033] The control terminal of the third switching device is connected to one end of the fourth resistor and the control unit, respectively. The input terminal of the third switching device is connected to the control terminal of the first switching device. The output terminal of the third switching device and the other end of the fourth resistor are both grounded.

[0034] Secondly, this application also provides a proportional solenoid valve driving system, which includes:

[0035] Proportional solenoid valve;

[0036] Power supplies, including trigger power supplies and drive power supplies;

[0037] As shown in the above proportional solenoid valve drive circuit;

[0038] The proportional solenoid valve drive circuit is connected to the proportional solenoid valve, the trigger power supply, and the drive power supply, respectively.

[0039] The above-mentioned one or more technical solutions provided in this application may have the following advantages or at least achieve the following technical effects:

[0040] This application provides a proportional solenoid valve drive circuit and system. A sampling module collects the drive current of the proportional solenoid valve and outputs a first sampling voltage. A comparison module compares the first sampling voltage with a first preset voltage and outputs an adjustment signal. A trigger module outputs a trigger signal based on the adjustment signal and a trigger power supply. A power drive module outputs a drive signal based on the trigger signal, driving the power module to adjust the drive current output from the drive power supply to the proportional solenoid valve. Thus, the trigger signal is adjusted according to changes in the drive current, thereby adjusting the drive signal output by the power drive module. This allows the power module to adjust the drive current output from the drive power supply to the proportional solenoid valve based on the drive signal. The drive current detection stage, change judgment stage, adjustment trigger stage, and adjustment stage are all implemented through hardware circuitry, eliminating the need for complex control programs. When applied to drive different proportional solenoid valves, only the magnitude of the first preset voltage needs to be adjusted, improving the applicability of the proportional solenoid valve drive circuit. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of the proportional solenoid valve drive circuit in Embodiment 1 of this application;

[0043] Figure 2 This is a circuit schematic diagram of one embodiment of the proportional solenoid valve drive circuit of this application;

[0044] Figure 3 This is a schematic diagram of the proportional solenoid valve drive circuit in Embodiment 2 of this application.

[0045] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0047] It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0048] In this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an apparatus or method that includes a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an apparatus or method. Without further limitation, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the apparatus or method that includes that element.

[0049] Furthermore, in this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. If the embodiments of this application involve descriptions of "first," "second," etc., such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0050] In this application, the suffixes such as "module," "component," or "unit" used to denote elements are used only for illustrative purposes and have no specific meaning in themselves. Therefore, "module," "component," or "unit" can be used interchangeably. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. Furthermore, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0051] Given the technical problem that existing proportional solenoid valve driving methods require different control programs to control different types of proportional solenoid valves, resulting in low applicability, this application provides a motor-driven proportional solenoid valve driving circuit and system, the overall concept of which is as follows:

[0052] The proportional solenoid valve drive circuit includes: a sampling module connected to the proportional solenoid valve for detecting the drive current of the proportional solenoid valve and outputting a first sampling voltage; a comparison module connected to the sampling module for comparing the first sampling voltage with a first preset voltage and outputting an adjustment signal; a trigger module connected to both the trigger power supply and the comparison module for outputting a trigger signal based on the output voltage of the trigger power supply and the adjustment signal; a power drive module connected to the trigger module for outputting a drive signal based on the trigger signal; and a power module connected to the drive power supply, the power drive module, and the proportional solenoid valve for adjusting the drive current output from the drive power supply to the proportional solenoid valve based on the drive signal, so that the proportional solenoid valve operates in constant current mode.

[0053] This application provides a motor proportional solenoid valve drive circuit and system. A sampling module collects the drive current of the proportional solenoid valve and outputs a first sampling voltage. A comparison module compares the first sampling voltage with a first preset voltage and outputs an adjustment signal. A trigger module outputs a trigger signal based on the adjustment signal and a trigger power supply. A power drive module outputs a drive signal based on the trigger signal, driving the power module to adjust the drive current output from the drive power supply to the proportional solenoid valve. Thus, the trigger signal is adjusted according to changes in the drive current, thereby adjusting the drive signal output by the power drive module. This allows the power module to adjust the drive current output from the drive power supply to the proportional solenoid valve according to the drive signal. The drive current detection stage, change judgment stage, adjustment trigger stage, and adjustment stage are all implemented through hardware circuitry, eliminating the need for complex control programming. When applied to drive different proportional solenoid valves, only the magnitude of the first preset voltage needs to be adjusted, improving the applicability of the proportional solenoid valve drive circuit.

[0054] The proportional solenoid valve drive circuit and system used in the technical implementation of this application will be described in detail below with reference to the accompanying drawings and specific embodiments:

[0055] Example 1

[0056] Reference Figures 1 to 2 , Figure 1 This is a schematic diagram of the proportional solenoid valve drive circuit according to Embodiment 1 of this application. Figure 2 This is a circuit schematic diagram of one embodiment of the proportional solenoid valve drive circuit of this application. This application provides a proportional solenoid valve drive circuit, which may include:

[0057] The sampling module, connected to the proportional solenoid valve, is used to detect the drive current of the proportional solenoid valve and output the first sampling voltage.

[0058] The comparison module, connected to the sampling module, is used to compare the magnitude of the first sampled voltage with the first preset voltage and output an adjustment signal.

[0059] The trigger module is connected to the trigger power supply and the comparator module respectively, and is used to output a trigger signal according to the output voltage of the trigger power supply and the adjustment signal;

[0060] The power drive module, connected to the trigger module, is used to output a drive signal according to the trigger signal;

[0061] The power module is connected to the drive power supply, the power drive module, and the proportional solenoid valve respectively. It is used to adjust the drive current output from the drive power supply to the proportional solenoid valve according to the drive signal, so that the proportional solenoid valve operates in constant current mode.

[0062] In this embodiment, when the proportional solenoid valve drive circuit is powered on, the trigger module outputs a trigger signal based on the output voltage of the trigger power supply; the power drive module outputs a drive signal based on the trigger signal; and the power module, based on the drive signal, controls the drive power supply to output a drive current to the proportional solenoid valve, thereby driving the proportional solenoid valve to operate. The trigger power supply is configured according to the actual trigger module and / or power drive module used, and the drive power supply is configured according to the actual proportional solenoid valve used.

[0063] It is understandable that the trigger power supply and drive power supply can be the power module set in the proportional solenoid valve drive circuit, or the power supply provided by other devices outside the proportional solenoid valve drive circuit. The specific settings can be configured according to the actual usage requirements.

[0064] When the proportional solenoid valve starts working, the drive current will fluctuate according to the actual usage. The sampling module can collect the drive current in real time and output a first sampling voltage. The comparison module compares the first sampling voltage with a first preset voltage in real time and outputs an adjustment signal to achieve real-time monitoring of the drive current. After receiving the adjustment signal, the trigger module obtains a trigger signal based on the adjustment signal and the output voltage of the trigger power supply. The trigger power drive module outputs a drive signal, thereby adjusting the trigger signal according to the adjustment signal to regulate the drive signal. The drive power module controls the drive current output by the drive power supply to the proportional solenoid valve according to the adjusted drive signal, realizing real-time feedback of the drive current and controlling the drive current to make the proportional solenoid valve work in constant current mode. The first preset voltage can be set according to actual usage requirements. The first preset voltage can be provided by a preset voltage source or by a DAC (Digital to Analog Converter). The DAC can be a standalone digital to analog converter or a DAC module from other devices.

[0065] In this embodiment, as Figure 2As shown, the sampling module may include a sampling resistor R1. One end of the sampling resistor R1 is connected to the power module, and the other end is connected to the coil L of the proportional solenoid valve. The sampling resistor R1 can acquire the drive current output from the power module to the proportional solenoid valve in real time, and thus, the first sampling voltage can be obtained based on the voltage drop across the sampling resistor R1.

[0066] As one implementation, the proportional solenoid valve drive circuit may further include;

[0067] The operational amplifier module, connected to the sampling module, is used to amplify the first sampled voltage to obtain the amplified sampled voltage;

[0068] The comparison module, connected to the operational amplifier module, is used to compare the amplified sampled voltage with the first preset voltage and output an adjustment signal.

[0069] In this embodiment, after acquiring the first sampling voltage across the sampling resistor R1, to avoid the first sampling voltage being too small and affecting control accuracy, an operational amplifier module can be set to amplify the first sampling voltage according to a first preset operational amplifier factor. By comparing the amplified sampling voltage with the first preset voltage, it can be determined whether the drive current needs to be adjusted. The first preset operational amplifier factor can be set according to actual usage requirements.

[0070] It is understandable that when the operational amplifier module is set, the first preset voltage to be compared with the amplified sampling voltage can be obtained by amplifying the first preset voltage to be compared with the first sampling voltage by a first preset operational amplifier factor.

[0071] Specifically, such as Figure 2 As shown, the operational amplifier module may include operational amplifier U3. The power supply terminal of operational amplifier U3 is connected to the power supply, and the ground terminal of operational amplifier U3 is grounded to 0V. The negative input terminal of operational amplifier U3 is connected to one end of resistor R15 and one end of resistor R16, respectively. The other end of resistor R15 is grounded to 0V, and the other end of resistor R16 is connected to the other end of resistor R1. The positive input terminal of operational amplifier U3 is connected to one end of resistor R13 and one end of resistor R14, respectively. The other end of resistor R13 is connected to one end of resistor R1, and the other end of resistor R14 is connected to the power supply. The output terminal of operational amplifier U3 is connected to the comparator module, thereby acquiring the voltage across sampling resistor R1 to obtain a first sampling voltage. The first sampling voltage is then amplified by operational amplifier U3 to obtain an amplified sampling voltage, which is then output to the comparator module.

[0072] The power supply can be an independent power module set in the proportional solenoid valve drive circuit, or it can be a power supply provided by other devices outside the proportional solenoid valve drive circuit. The specific settings can be configured according to actual usage requirements.

[0073] Specifically, such as Figure 2 As shown, the comparison module may include a high-speed comparator U4. The power supply terminal of the high-speed comparator U4 is connected to the power supply, which powers the high-speed comparator U4. The positive input terminal of the high-speed comparator U4 is connected to the power supply, and the ground terminal of the high-speed comparator U4 is grounded to 0V. The power supply outputs a first preset voltage. The negative input terminal of the high-speed comparator U4 is connected to the output terminal of the operational amplifier U3 to compare the amplified sampling voltage output by the operational amplifier U3 with the magnitude of the first preset voltage and output an adjustment signal.

[0074] It is understandable that the trigger power supply, drive power supply, and power supply can be provided by a single power module, or they can be provided by different power modules. When the trigger power supply, drive power supply, and power supply are provided by a single power module, that power module can output power of different voltage levels.

[0075] like Figure 2 As shown, in one example, the power supply can output a voltage of +24V, a voltage of +2.5V, and a voltage of +5V.

[0076] Specifically, such as Figure 2 As shown, the power drive module may include a half-bridge driver U8. Pin 1 of the half-bridge driver U8 is connected to the power supply and one end of resistor R3, respectively. The other end of resistor R3 is connected to the positive terminal of diode D5. The negative terminal of diode D5 is connected to pin 8 of the half-bridge driver U8. Pin 4 of the half-bridge driver U8 is grounded. The power supply provides power to the half-bridge driver U8. Pins 2 and 3 of the half-bridge driver U8 are both connected to the trigger module and are triggered to work according to the trigger signal output by the trigger module. Pins 5, 6, and 7 of the half-bridge driver U8 are all connected to the power module and output drive signals to the power module.

[0077] In this embodiment, the triggering module may include:

[0078] The trigger, connected to the trigger power supply and the comparator module respectively, is used to output the first trigger signal according to the adjustment signal and the output voltage;

[0079] An inverter, connected to the trigger power supply and the comparator module, is used to invert the regulation signal and the output voltage to output a second trigger signal.

[0080] The power drive module is connected to a trigger and an inverter respectively, and is used to output a drive signal according to the first trigger signal and the second trigger signal.

[0081] In this embodiment, since the half-bridge driver U8 requires two trigger signals, the trigger module can output the first trigger signal and the second trigger signal through a flip-flop and an inverter, respectively, to trigger the half-bridge driver U8.

[0082] Specifically, such as Figure 2 As shown, the input of flip-flop U5 is connected to the output of high-speed comparator U4 and one end of resistor R17, respectively. The other end of resistor R17 is connected to the power supply. The output of flip-flop U5 is connected to pin 3 of half-bridge driver U8. Flip-flop U5 outputs a first trigger signal to half-bridge driver U8 based on the output voltage of the power supply and the adjustment signal output by high-speed comparator U4. The input of inverter U6 is connected to the output of high-speed comparator U4 and one end of resistor R17, respectively. The output of inverter U6 is connected to pin 2 of half-bridge driver U8. Flip-flop U5 outputs a second trigger signal to half-bridge driver U8 based on the output voltage of the power supply and the adjustment signal output by high-speed comparator U4.

[0083] In this embodiment, as Figure 2 As shown, the power module may include a first power device and a second power device;

[0084] The control terminal of the first power device is connected to the power drive module, the input terminal of the first power device is connected to the drive power supply, the output terminal of the first power device is connected to the proportional solenoid valve and the input terminal of the second power device respectively, the control terminal of the second power device is connected to the power drive module, and the output terminal of the second power device is grounded.

[0085] In this embodiment, a half-bridge driver U8 drives two power devices to control the drive current output from the drive power supply to the proportional solenoid valve. By flexibly controlling the on / off state of the two power devices, the magnitude of the drive current can be adjusted. This eliminates the need for a freewheeling diode, preventing excessive current flowing through the freewheeling diode when driving a high-current proportional solenoid valve, which would generate excessive heat and increase cooling costs. The first and second power devices can be selected according to actual requirements.

[0086] Specifically, such as Figure 2As shown, the first power device includes a field-effect transistor (FET) Q2, and the second power device includes a field-effect transistor (FET) Q1. The gate of FET Q2 is connected to one end of capacitor C1, one end of resistor R6, one end of resistor R4, and the anode of diode D6, respectively. The other ends of capacitor C1 and resistor R6 are both connected to pin 6 of half-bridge driver U8. The cathode of diode D6 is connected to one end of resistor R5. The other ends of resistor R4 and resistor R5 are both connected to pin 7 of half-bridge driver U8, receiving the drive signal output by half-bridge driver U8. The drain of FET Q2 is connected to the drive power supply, receiving the output current of the drive power supply. The source of FET Q2 is connected to... Pin 6 of the half-bridge driver U8, the drain of the field-effect transistor Q1, and one end of the sampling resistor R1 are connected to send the output current to the field-effect transistor Q1, and the drive current is output to the proportional solenoid valve through the sampling resistor R1. The gate of the field-effect transistor Q1 is connected to one end of the capacitor C2, one end of the resistor R7, the anode of the diode D7, and one end of the resistor R9. The other ends of the capacitor C2 and the other ends of the resistor R7 are grounded to 0V. The cathode of the diode D7 is connected to one end of the resistor R9. The other ends of the resistor R9 and the other ends of the resistor R8 are connected to pin 5 of the half-bridge driver U8 to receive the drive signal output by the half-bridge driver U8. The source of the field-effect transistor Q1 is grounded to 0V. Thus, different drive signals can control the first and second power devices to adjust the output current of the drive power supply, outputting a constant drive current to the proportional solenoid valve.

[0087] This embodiment provides a proportional solenoid valve drive circuit. Through a sampling resistor, operational amplifier, and high-speed comparator, it samples and compares the drive current of the proportional solenoid valve, outputting an adjustment signal. A trigger signal is output based on the adjustment signal via a trigger and an inverter. A half-bridge driver then drives power devices based on the trigger signal to control the drive current of the proportional solenoid valve. The detection, change judgment, adjustment trigger, and adjustment stages of the drive current are all implemented through hardware circuitry, eliminating the need for complex control programming. When driving different proportional solenoid valves, only the magnitude of the first preset voltage needs to be adjusted, improving the applicability of the proportional solenoid valve drive circuit. Furthermore, by controlling two power devices, the drive current can be flexibly adjusted without the need for a freewheeling diode. When driving a high-current proportional solenoid valve, there is no need for a corresponding heat dissipation structure for the freewheeling diode, reducing heat dissipation costs and further lowering the drive cost of the proportional solenoid valve.

[0088] Example 2

[0089] Furthermore, refer to Figure 2 and Figure 3 , Figure 3This is a schematic diagram of the proportional solenoid valve drive circuit according to Embodiment 2 of this application. This application provides a second embodiment of a proportional solenoid valve drive circuit. Based on Embodiment 1 above, the proportional solenoid valve drive circuit may further include:

[0090] The short-circuit protection module, connected to the trigger module, is used to pull down the trigger signal and control the power drive module to stop outputting drive signals when a short-circuit fault occurs in the proportional solenoid valve.

[0091] In this embodiment, a short circuit fault will occur when the proportional solenoid valve is reverse-connected, leading to a safety issue. By using a short-circuit protection module, when a short circuit fault occurs in the proportional solenoid valve, the trigger signal is pulled low, controlling the power drive module to stop outputting drive signals, thus preventing the proportional solenoid valve from being reverse-connected and causing a safety accident.

[0092] In this embodiment, the short-circuit protection module may include:

[0093] The sampling unit, connected to the drive power supply, is used to collect the output current of the drive power supply and output a second sampling voltage;

[0094] The comparison unit, connected to the sampling unit, is used to output a self-locking control signal when the second sampled voltage is greater than the second preset voltage;

[0095] The self-locking unit, connected to the comparison unit and the trigger module, is used to self-lock according to the self-locking control signal, pull down the trigger signal, and control the power drive module to stop outputting drive signals.

[0096] In this embodiment, as Figure 2 As shown, when the proportional solenoid valve drive circuit is powered on, the MOSFET Q2 is turned on. If the proportional solenoid valve experiences a short circuit fault, the current flowing through the MOSFET Q2 will be too large, causing damage to the MOSFET and resulting in a safety issue. Therefore, the output current from the drive power supply to the MOSFET can be collected to determine if the output current is too large, thus identifying whether the proportional solenoid valve has a short circuit fault and implementing short circuit protection.

[0097] In practice, a sampling unit can be used to collect the output current of the drive power supply and output a second sampled voltage. A comparison unit can then compare the second sampled voltage with a second preset voltage to trigger a self-locking unit for short-circuit protection. The second preset voltage is set according to the actual usage conditions.

[0098] Specifically, such as Figure 2 As shown, the sampling unit may include a sampling resistor R2. One end of the sampling resistor R2 is connected to the driving power supply, and the other end of the sampling resistor R2 is connected to the drain of the field-effect transistor Q2. The sampling resistor R2 can acquire the output current from the driving power supply to the field-effect transistor Q2 in real time, and thus, based on the voltage drop across the sampling resistor R2, the second sampling voltage can be obtained.

[0099] After acquiring the second sampling voltage across the sampling resistor R2, to avoid the second sampling voltage being too small and affecting control accuracy, an operational amplifier unit can be set to amplify the second sampling voltage according to a preset second operational amplifier factor. By comparing the amplified second sampling voltage with the second preset voltage, it can be determined whether the proportional solenoid valve has a short circuit fault. The second preset operational amplifier factor can be set according to actual usage requirements.

[0100] It is understandable that, after setting the operational amplifier unit, the second preset voltage that is compared with the amplified second sampling voltage can be obtained by amplifying the second preset voltage by the second preset operational amplifier factor.

[0101] Specifically, such as Figure 2 As shown, the operational amplifier unit may include operational amplifier U1. The power supply terminal of operational amplifier U1 is connected to the power supply, and the ground terminal of operational amplifier U1 is grounded to 0V. The negative input terminal of operational amplifier U1 is connected to one end of resistor R27 and one end of resistor R26, respectively. The other end of resistor R16 is connected to the other end of resistor R2. The positive input terminal of operational amplifier U1 is connected to one end of resistor R11 and one end of resistor R10, respectively. The other end of resistor R11 is connected to one end of resistor R1, and the other end of resistor R10 is grounded to 0V. The output terminal of operational amplifier U1 is connected to the other end of resistor R27 and the comparator unit, thereby acquiring the voltage across sampling resistor R2 to obtain a second sampling voltage. The second sampling voltage is then amplified by operational amplifier U1 to obtain an amplified second sampling voltage, which is then output to the comparator unit.

[0102] Specifically, such as Figure 2 As shown, the comparison unit may include comparator U2. The power supply terminal of comparator U2 is connected to a power supply, which powers the comparator U2. The positive input terminal of comparator U2 is also connected to the power supply, and its ground terminal is grounded to 0V. The power supply outputs a second preset voltage. The negative input terminal of comparator U2 is connected to the output terminal of operational amplifier U1 to compare the amplified second sample voltage output by operational amplifier U1 with the second preset voltage. The output terminal of comparator U2 is connected to one end of resistor R12 and a self-locking unit, while the other end of resistor R12 is connected to the power supply. Therefore, based on the comparison result of the amplified second sample voltage and the second preset voltage, and the output voltage of the power supply, comparator U2 outputs a self-locking control signal to control the self-locking unit to self-lock, pull down the trigger signal, and control the power drive module to stop outputting drive signals.

[0103] Specifically, the self-locking unit may include a first switching device, a second switching device, a first diode, and a second diode;

[0104] The control terminal of the first switching device is connected to the comparison unit, one end of the first resistor, one end of the first capacitor, the output terminal of the second switching device, and the reset unit. The output terminal of the first switching device, the other end of the first resistor, and the other end of the first capacitor are all grounded. The input terminal of the first switching device is connected to the control terminal of the second switching device, one end of the third resistor, the cathode of the first diode, the cathode of the second diode, and the control unit. The anodes of the first diode and the second diode are both connected to the trigger module. The other end of the third resistor is connected to the input terminal of the second switching device and the power supply.

[0105] In this embodiment, the first and second switching devices can be selected according to actual usage requirements. Preferably, as follows: Figure 2 As shown, the first switching device includes transistor Q4, the second switching device includes transistor Q3, the first diode includes diode D3, and the second diode includes diode D4. The base of transistor Q4 is connected to one end of resistor R20, one end of capacitor C3, the collector of transistor Q3, and one end of resistor R21. The other end of resistor R21 is connected to the cathode of diode D2. The anode of diode D2 is connected to the output of comparator U2. The other end of resistor R20, the other end of capacitor C3, and the emitter of transistor Q4 are all grounded. The collector of transistor Q4 is connected to the cathode of diode D3, the cathode of diode D4, one end of resistor R19, and the base of transistor Q3. The anode of diode D3 is connected to the output of inverter U6. The anode of diode D4 is connected to the output of trigger U5. The other end of resistor R19 is connected to one end of resistor R18 and the emitter of transistor Q3.

[0106] In practice, when the current in resistor R2 is too large, the self-locking control signal output by comparator U2 is sent to the base of transistor Q4, controlling transistor Q4 to conduct. This pulls down the cathodes of diodes D3 and D4, thereby pulling down the trigger signals output by trigger U5 and inverter U6. This controls the power drive module to stop outputting drive signals. Furthermore, the conduction of transistor Q4 pulls down the base of transistor Q3, causing transistor Q3 to conduct. This achieves self-locking between transistors Q4 and Q3, enabling troubleshooting and resolving short-circuit faults in the proportional solenoid valve.

[0107] In this embodiment, the short-circuit protection module may further include:

[0108] The control unit is used to output a reset control signal;

[0109] The reset unit, connected to the control unit and the self-locking unit, is used to control the self-locking unit to unlock according to the reset control signal.

[0110] In this embodiment, as Figure 2As shown, the control unit may include a microcontroller U7 and a resistor R24. Pin 1 of the microcontroller U7 is connected to one end of resistor R24, the cathode of Zener diode D1, and one end of resistor R25, respectively. The other end of resistor R24 ​​and the anode of Zener diode D1 are both grounded to 0V. The other end of resistor R25 is connected to the cathodes of diodes D3 and D4. The microcontroller U7 can determine whether the self-locking unit is in a self-locking state by detecting whether the voltage at one end of resistor R24 ​​is high or low. The microcontroller U7 can detect whether the voltage at one end of resistor R24 ​​is high or low upon receiving a short-circuit fault clearance signal, or it can detect the voltage at one end of resistor R24 ​​at preset time intervals. When a low voltage is detected at one end of resistor R24, the microcontroller U7 determines that the self-locking unit is in a self-locking state and outputs a reset control signal. The short-circuit fault clearance signal can be output by the detection circuit or manually provided by the user, depending on the specific application. The preset time interval can also be set according to the actual usage.

[0111] Specifically, the reset unit may include a third switching device;

[0112] The control terminal of the third switching device is connected to one end of the fourth resistor and the control unit, respectively. The input terminal of the third switching device is connected to the control terminal of the first switching device. The output terminal of the third switching device and the other end of the fourth resistor are both grounded.

[0113] In this embodiment, the third switching device can be selected according to actual usage requirements. Preferably, such as... Figure 2 As shown, the third switching device may include transistor Q6, and the fourth resistor may include resistor R22. The base of transistor Q6 is connected to one end of resistor R23, and the other end of resistor R23 is connected to pin 2 of microcontroller U7 and one end of resistor R22, respectively. The collector of transistor Q6 is connected to the base of transistor Q4, and the emitter of transistor Q6 and the other end of resistor R22 are both grounded.

[0114] In the specific implementation, when the microcontroller detects that the voltage at one end of resistor R24 ​​is low, it determines that the self-locking unit is in a self-locking state, outputs a reset control signal, controls transistor Q6 to conduct, pulls down the base voltage of transistor Q4, controls transistor Q4 to cut off, thereby controlling transistor Q3 to cut off, so that transistors Q4 and Q3 are unlocked.

[0115] This embodiment provides a proportional solenoid valve drive circuit. Through a sampling resistor, operational amplifier, and high-speed comparator, the output current from the drive power supply to the power device is sampled and compared. When the output current from the drive power supply to the power device is too large, a short-circuit fault is detected in the proportional solenoid valve. A self-locking control signal is output to control the two transistors to self-lock, pulling down the trigger signal of the half-bridge driver, causing the half-bridge driver to stop working. This prevents the drive power supply from continuously outputting excessive current and damaging the power device, achieving short-circuit protection against reverse connection of the proportional solenoid valve, thus improving the safety of the proportional solenoid valve drive circuit. Furthermore, when the two transistors are in the self-locking state, short-circuit fault detection and troubleshooting of the proportional solenoid valve can be performed without de-energizing the entire proportional solenoid valve drive circuit. After the short-circuit fault is cleared, the self-locking state is automatically released by controlling the on / off state of the third switching device by detecting the self-locking state of the two transistors, improving the user experience.

[0116] Example 3

[0117] Based on the same inventive concept, this application also provides a proportional solenoid valve driving system, which may include:

[0118] Proportional solenoid valve;

[0119] Power supplies, including trigger power supplies and drive power supplies;

[0120] As shown in the above proportional solenoid valve drive circuit;

[0121] The proportional solenoid valve drive circuit is connected to the proportional solenoid valve, the trigger power supply, and the drive power supply, respectively.

[0122] It should be noted that the specific structure of the proportional solenoid valve drive circuit refers to Embodiment 1 or 2 above. Since this embodiment adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be described in detail here.

[0123] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A proportional solenoid valve drive circuit, characterized in that, The proportional solenoid valve drive circuit includes: A sampling module, connected to a proportional solenoid valve, is used to detect the drive current of the proportional solenoid valve and output a first sampling voltage. The comparison module, connected to the sampling module, is used to compare the magnitude of the first sampled voltage with the first preset voltage and output an adjustment signal; The trigger module is connected to the trigger power supply and the comparison module respectively, and is used to output a trigger signal according to the output voltage of the trigger power supply and the adjustment signal; A power drive module, connected to the trigger module, is used to output a drive signal according to the trigger signal; A power module is connected to the drive power supply, the power drive module, and the proportional solenoid valve, respectively, and is used to adjust the drive current output by the drive power supply to the proportional solenoid valve according to the drive signal, so that the proportional solenoid valve operates in constant current mode.

2. The proportional solenoid valve drive circuit as described in claim 1, characterized in that, The triggering module includes: A trigger, connected to the trigger power supply and the comparison module respectively, is used to output a first trigger signal according to the adjustment signal and the output voltage; An inverter, connected to the trigger power supply and the comparison module, is used to invert the adjustment signal and the output voltage to output a second trigger signal. The power drive module is connected to the trigger and the inverter respectively, and is used to output the drive signal according to the first trigger signal and the second trigger signal.

3. The proportional solenoid valve drive circuit as described in claim 1, characterized in that, The proportional solenoid valve drive circuit also includes; An operational amplifier module, connected to the sampling module, is used to amplify the first sampling voltage to obtain an amplified sampling voltage; The comparison module is connected to the operational amplifier module and is used to compare the amplified sampled voltage with the first preset voltage and output the adjustment signal.

4. The proportional solenoid valve drive circuit as described in claim 1, characterized in that, The power module includes a first power device and a second power device; The control terminal of the first power device is connected to the power drive module, the input terminal of the first power device is connected to the drive power supply, the output terminal of the first power device is connected to the proportional solenoid valve and the input terminal of the second power device, the control terminal of the second power device is connected to the power drive module, and the output terminal of the second power device is grounded.

5. The proportional solenoid valve drive circuit as described in claim 1, characterized in that, The proportional solenoid valve drive circuit also includes: A short-circuit protection module, connected to the trigger module, is used to pull down the trigger signal and control the power drive module to stop outputting the drive signal when a short-circuit fault occurs in the proportional solenoid valve.

6. The proportional solenoid valve drive circuit as described in claim 5, characterized in that, The short-circuit protection module includes: A sampling unit, connected to the driving power supply, is used to collect the output current of the driving power supply and output a second sampling voltage. A comparison unit, connected to the sampling unit, is used to output a self-locking control signal when the second sampling voltage is greater than the second preset voltage; The self-locking unit is connected to the comparison unit and the triggering module, and is used to self-lock according to the self-locking control signal, pull down the triggering signal, and control the power drive module to stop outputting the drive signal.

7. The proportional solenoid valve drive circuit as described in claim 6, characterized in that, The short-circuit protection module also includes: The control unit is used to output a reset control signal; A reset unit, connected to the control unit and the self-locking unit, is used to control the self-locking unit to unlock according to the reset control signal.

8. The proportional solenoid valve drive circuit as described in claim 7, characterized in that, The self-locking unit includes a first switching device, a second switching device, a first diode, and a second diode; The control terminal of the first switching device is connected to the comparison unit, one end of the first resistor, one end of the first capacitor, the output terminal of the second switching device, and the reset unit. The output terminal of the first switching device, the other end of the first resistor, and the other end of the first capacitor are all grounded. The input terminal of the first switching device is connected to the control terminal of the second switching device, one end of the third resistor, the cathode of the first diode, the cathode of the second diode, and the control unit. The anodes of the first diode and the second diode are both connected to the trigger module. The other end of the third resistor is connected to the input terminal of the second switching device and the power supply.

9. The proportional solenoid valve drive circuit as described in claim 8, characterized in that, The reset unit includes a third switching device; The control terminal of the third switching device is connected to one end of the fourth resistor and the control unit, the input terminal of the third switching device is connected to the control terminal of the first switching device, and the output terminal of the third switching device and the other end of the fourth resistor are both grounded.

10. A proportional solenoid valve drive system, characterized in that, The proportional solenoid valve drive system includes: Proportional solenoid valve; Power supplies, including trigger power supplies and drive power supplies; The proportional solenoid valve drive circuit as described in any one of claims 1 to 9; The proportional solenoid valve drive circuit is connected to the proportional solenoid valve, the trigger power supply, and the drive power supply, respectively.

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