Electromagnetic valve driving circuit and gas appliance

Abstract

The electromagnetic valve driving circuit comprises a micro-control unit, an isolation unit, a rectification filtering unit and a switch unit, the micro-control unit is used for sending out alternating pulse signals, the input end of the isolation unit is connected with the output end of the micro-control unit, the input end of the rectification filtering unit is connected with the output end of the isolation unit, and the switch unit is connected with the rectification filtering unit. The switch unit is connected in series in a power supply loop of the electromagnetic valve. The control end of the switch unit is connected with the output end of the rectification filtering unit. When the micro-control unit fails to work due to abnormal conditions such as crash and damage, the output port of the micro-control unit cannot be overturned, the output signal is a direct current signal, the direct current signal cannot pass through the isolation unit, the control end of the switch unit has no voltage, and the switch unit is switched off, so that the power supply loop of the electromagnetic valve is switched off, and the electromagnetic valve is closed. The problem of fluid leakage caused by the fact that the micro-control unit crashes due to interference or is suddenly damaged due to other reasons and cannot control the electromagnetic valve to be closed is solved, and the safety is improved.

Description

Technical Field

[0001] The utility model relates to the technology of solenoid valve driving, in particular to a solenoid valve driving circuit and a gas appliance. Background Art

[0002] A solenoid valve is a basic automation component for controlling fluids. A solenoid valve usually includes a valve body, an electromagnetic coil disposed inside the valve body, a closing member, and a spring. The closing member has magnetism, and the spring is fixedly connected to the closing member. When powered on, the electromagnetic coil generates an electromagnetic force to overcome the pressure of the spring, lifting the closing member from the valve seat and opening the valve; when powered off, the electromagnetic force disappears, the spring resumes, and presses the closing member against the valve seat, closing the valve.

[0003] The control of the solenoid valve is usually achieved by a micro-control unit in cooperation with a control switch. Specifically, the control switch is connected in series in the power supply circuit of the electromagnetic coil, and the control end of the control switch is connected to the micro-control unit. The micro-control unit outputs a control signal to control the on / off of the control switch, thereby controlling the energization or de-energization of the electromagnetic coil.

[0004] When the solenoid valve is already open, if the micro-control unit is interfered and freezes, or suddenly fails due to other reasons, causing the micro-control unit to be unable to output a control signal, the solenoid valve cannot be closed when it needs to be closed, resulting in leakage of the controlled fluid and posing a safety hazard. Summary of the Utility Model

[0005] One of the technical problems to be solved by the utility model is to provide a solenoid valve driving circuit that can control the solenoid valve to automatically close when the micro-control unit is interfered and freezes, or suddenly fails due to other reasons and is unable to output a control signal, avoiding leakage of the controlled fluid and improving safety.

[0006] One of the technical problems to be solved by the utility model is to provide a gas appliance that can control the gas valve to automatically close when the micro-control unit is interfered and freezes, or suddenly fails due to other reasons and is unable to control the gas valve, avoiding gas leakage and improving safety.

[0007] The above first technical problem is solved by the following technical solutions:

[0008] A solenoid valve driving circuit, comprising:

[0009] A micro-control unit for emitting an alternating pulse signal;

[0010] An isolation unit, the input end of the isolation unit is connected to the output end of the micro-control unit for receiving the alternating pulse signal emitted by the micro-control unit, and the isolation unit is used to isolate DC signals;

[0011] A rectifying and filtering unit, the input end of the rectifying and filtering unit is connected to the output end of the isolation unit, and the rectifying and filtering unit is used to rectify and filter the alternating pulse signal and output a direct current signal;

[0012] A switching unit, the switching unit is connected in series in the power supply circuit of the solenoid valve, and the control end of the switching unit is connected to the output end of the rectifying and filtering unit.

[0013] The solenoid valve driving circuit provided by the present utility model includes a micro control unit, an isolation unit, a rectifying and filtering unit and a switching unit. The micro control unit is used to emit an alternating pulse signal. The input end of the isolation unit is connected to the output end of the micro control unit. The input end of the rectifying and filtering unit is connected to the output end of the isolation unit. The switching unit is connected in series in the power supply circuit of the solenoid valve, and the control end of the switching unit is connected to the output end of the rectifying and filtering unit. When the micro control unit has abnormal conditions such as crashing or damage and cannot work, at this time, the output port of the micro control unit cannot flip, and the output signal is either always a high-level signal or always a low-level signal, and both are direct current signals. Due to the characteristic of the isolation unit that it blocks direct current and passes alternating current, the direct current signal cannot pass through the isolation unit, the control end of the switching unit has no voltage, the switching unit is turned off, so that the power supply circuit of the solenoid valve is disconnected, the solenoid valve is closed, the fluid is cut off, avoiding the micro control unit from being interfered and crashing, or suddenly damaged for other reasons and unable to control the solenoid valve to close, resulting in the leakage of the controlled fluid, and improving the safety.

[0014] In one embodiment of the present utility model, the isolation unit includes an isolation capacitor, the first electrode of the isolation capacitor is connected to the output end of the micro control unit, and the second electrode of the isolation capacitor is connected to the input end of the rectifying and filtering unit.

[0015] In one embodiment of the present utility model, the rectifying and filtering unit includes a first diode, a second diode and a filtering capacitor. The anode of the first diode is grounded, the cathode of the first diode is respectively connected to the output end of the isolation unit and the anode of the second diode. The cathode of the second diode is respectively connected to the control end of the switching unit and the first electrode of the filtering capacitor, and the second electrode of the filtering capacitor is grounded.

[0016] In one embodiment of the present utility model, the switching unit includes an electronic switching tube. The first end of the electronic switching tube is connected to the first end of the solenoid valve, the second end of the solenoid valve is connected to the power supply of the solenoid valve, the second end of the electronic switching tube is grounded, and the control end of the electronic switching tube is connected to the output end of the rectifying and filtering unit.

[0017] In one embodiment of the present utility model, the solenoid valve driving circuit further includes a signal amplification unit. The input end of the signal amplification unit is connected to the output end of the micro control unit, and the output end of the signal amplification unit is connected to the input end of the isolation unit. The signal amplification unit is used to amplify the alternating pulse signal.

[0018] In one embodiment of the present utility model, the signal amplification unit includes a first resistor, a second resistor, and a triode. The first end of the first resistor is connected to a reference voltage source, the second end of the first resistor is respectively connected to the collector of the triode and the input end of the isolation unit, the emitter of the triode is grounded, the base of the triode is connected to the output end of the micro control unit, the first end of the second resistor is connected to the base of the triode, and the second end of the second resistor is connected to the emitter of the triode.

[0019] In one embodiment of the present utility model, the solenoid valve driving circuit further includes a third diode. The anode of the third diode is connected to the first end of the solenoid valve, the first end of the solenoid valve is connected to the switch unit, the second end of the solenoid valve is connected to the power supply of the solenoid valve, and the cathode of the third diode is connected to the second end of the solenoid valve.

[0020] In one embodiment of the present utility model, the solenoid valve includes an open-valve electromagnetic coil, a close-valve electromagnetic coil, an open-valve switch, and a close-valve switch. The open-valve electromagnetic coil and the open-valve switch are connected in series to form an open-valve branch, the close-valve electromagnetic coil and the close-valve switch form a close-valve branch, the open-valve branch and the close-valve branch are connected in parallel in the power supply circuit of the solenoid valve, and the control ends of the open-valve switch and the close-valve switch are both connected to the micro control unit;

[0021] The solenoid valve driving circuit further includes a solenoid valve detection unit. The input end of the solenoid valve detection unit is connected to the close-valve branch, and the output end of the solenoid valve detection unit is connected to the micro control unit. The solenoid valve detection unit is used to detect whether the close-valve branch is open-circuited and feed the detection result back to the micro control unit.

[0022] In one embodiment of the present utility model, the solenoid valve detection unit includes a third resistor, a fourth resistor, and a fifth resistor. The first end of the third resistor is connected to the close-valve branch, the second end of the third resistor is respectively connected to the first end of the fourth resistor and the first end of the fifth resistor, the second end of the fourth resistor is grounded, and the second end of the fifth resistor is connected to the micro control unit.

[0023] The above second technical problem is solved by the following technical solutions:

[0024] A gas appliance includes a gas valve and the solenoid valve drive circuit of the present utility model. The solenoid valve drive circuit includes:

[0025] A micro-control unit for sending out alternating pulse signals;

[0026] An isolation unit, the input end of which is connected to the output end of the micro-control unit for receiving the alternating pulse signals sent out by the micro-control unit, and the isolation unit is used for isolating DC signals;

[0027] A rectification and filtering unit, the input end of which is connected to the output end of the isolation unit, and the rectification and filtering unit is used for rectifying the alternating pulse signals and outputting DC signals;

[0028] A switching unit, which is connected in series in the power supply circuit of the gas valve, and the control end of the switching unit is connected to the output end of the rectification and filtering unit.

[0029] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present utility model, nor is it used to limit the scope of the present utility model. Other features of the present utility model will become easily understood through the following description. Description of the Drawings

[0030] The present utility model will be further described in detail below with reference to the drawings and embodiments.

[0031] Figure 1 It is a schematic structural diagram of a solenoid valve drive circuit provided by an embodiment of the present utility model;

[0032] Figure 2 It is a circuit diagram of a solenoid valve drive circuit provided by an embodiment of the present utility model;

[0033] Figure 3 It is a circuit diagram of another solenoid valve drive circuit provided by an embodiment of the present utility model;

[0034] Figure 4 It is a circuit diagram of another solenoid valve drive circuit provided by an embodiment of the present utility model;

[0035] Figure 5 It is a flowchart of a solenoid valve drive method provided by an embodiment of the present utility model;

[0036] Figure 6 It is a flowchart of another solenoid valve drive method provided by an embodiment of the present utility model. Description of the Drawings:

[0038] 110. Microcontroller unit; 120. Isolation unit; 130. Rectifier and filter unit; 140. Switch unit; 150. Signal amplification unit; 160. Solenoid valve detection unit; 200. Solenoid valve. Detailed implementation manners

[0039] To make the technical problems solved by the present utility model, the technical solutions adopted, and the achieved technical effects clearer, the technical solutions of the embodiments of the present utility model will be further described in detail below with reference to the drawings. Obviously, the described embodiments are only part of the embodiments of the present utility model, rather than all embodiments. Based on the embodiments in the present utility model, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present utility model.

[0040] In the description of the present utility model, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal connection of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0041] In the present utility model, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "above and to the right", and "above and to the left" of the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "below and to the right", and "below and to the left" of the second feature includes the first feature being directly below and obliquely below the second feature, or simply indicating that the horizontal height of the first feature is lower than that of the second feature. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0042] Embodiment 1

[0043] Figure 1 Shown in the figure is a structural schematic diagram of a solenoid valve drive circuit provided by an embodiment of the present utility model. As Figure 1 shown, the solenoid valve drive circuit includes:

[0044] Microcontroller unit 110 is configured to emit an alternating pulse signal. A microcontroller unit (MCU), also known as a single-chip microcomputer or a microcontroller, is a device that appropriately reduces the frequency and specifications of a central processing unit (CPU), and integrates peripherals such as memory, timer, USB, A / D converter, UART, PLC, and DMA on a single chip to form a computer at the chip level, enabling different combinations of control for different application scenarios.

[0045] Isolation unit 120, the input end of isolation unit 120 is connected to the output end of microcontroller unit 110, and is configured to receive the alternating pulse signal emitted by microcontroller unit 110. Isolation unit 110 is configured to isolate DC signals and allow the alternating pulse signal to pass through. Exemplarily, isolation unit 120 can be an isolation device such as a capacitor, a transformer, etc. for isolating DC signals. The embodiments of the present invention do not make limitations here, as long as it can isolate DC signals.

[0046] Rectification and filtering unit 130, the input end of rectification and filtering unit 130 is connected to the output end of isolation unit 120. Rectification and filtering unit 130 is configured to rectify and filter the alternating pulse signal passing through isolation unit 120 and output a DC signal. Exemplarily, rectification and filtering unit 130 can include a rectification circuit and a filtering circuit. The rectification circuit can include a half-wave rectification circuit, a full-wave rectification circuit, a bridge rectification circuit, etc. The filtering circuit can include a capacitor filtering circuit, an inductor filtering circuit, an RC filtering circuit, an LC filtering circuit, etc. The embodiments of the present invention do not make limitations here, as long as it can achieve the rectification and filtering function.

[0047] Switch unit 140 is connected in series in the power supply circuit of solenoid valve 200, and the control end of switch unit 140 is connected to the output end of rectification and filtering unit 130. Exemplarily, as Figure 1 shown, the first end of solenoid valve 200 is connected to the first end of switch unit 140, the second end of solenoid valve 200 is connected to a power supply, the second end of switch unit 140 is grounded, and the control end of switch unit 140 is connected to the output end of rectification and filtering unit 130. This solenoid valve 200 can be arranged in a fluid pipeline to control fluids, such as water, gas, etc. The embodiments of the present invention do not make limitations here. Switch unit 140 includes at least one electrically controlled switch, and the electrically controlled switch is connected in series in the power supply circuit of solenoid valve 200, and the control end of the electrically controlled switch is connected to the output end of rectification and filtering unit 130. In some other embodiments of the present invention, switch unit may also include multiple electrically controlled switches and other components, such as resistors. The embodiments of the present invention do not make limitations here, as long as it can control the on / off of the power supply circuit of solenoid valve 200.

[0048] Exemplarily, when the microcontroller unit 110 receives an open valve command, in response to the open valve command, it controls the output port to flip once every preset time duration, and outputs an alternating pulse signal to the isolation unit 120. Due to the characteristic of the isolation unit 120 of blocking direct current and passing alternating current, the alternating pulse signal can pass through the isolation unit 120 and be transmitted to the rectification and filtering unit 130. The rectification and filtering unit 130 rectifies and filters the alternating pulse signal to obtain a direct current signal, and outputs it to the control end of the switching unit 140 to drive the switching unit 140 to conduct, so that the power supply circuit of the solenoid valve 200 is connected, and the solenoid valve 200 opens to allow the fluid to pass through.

[0049] When the microcontroller unit 110 receives a close valve command, in response to the close valve command, it outputs a direct current signal (such as a direct current level signal) to the isolation unit 120. Due to the characteristic of the isolation unit 120 of blocking direct current and passing alternating current, the direct current signal cannot pass through the isolation unit 120, the control end of the switching unit 140 has no voltage, the switching unit 140 is turned off, so that the power supply circuit of the solenoid valve 200 is disconnected, and the solenoid valve 200 closes to cut off the fluid.

[0050] When the microcontroller unit 110 malfunctions and cannot work, such as crashing or being damaged, at this time, the output port of the microcontroller unit 110 cannot flip, and the output signal is either always a high-level signal or always a low-level signal, both of which are direct current signals. Due to the characteristic of the isolation unit 120 of blocking direct current and passing alternating current, the direct current signal cannot pass through the isolation unit 120, the control end of the switching unit 140 has no voltage, the switching unit 140 is turned off, so that the power supply circuit of the solenoid valve 200 is disconnected, and the solenoid valve 200 closes to cut off the fluid, avoiding the problem that the microcontroller unit 110 is interfered and crashes, or suddenly damaged for other reasons and cannot control the solenoid valve to close, resulting in the leakage of the controlled fluid, thus improving the safety.

[0051] The solenoid valve drive circuit provided by the embodiment of the present utility model includes a micro-control unit, an isolation unit, a rectification and filtering unit, and a switching unit. The micro-control unit is used to emit an alternating pulse signal. The input end of the isolation unit is connected to the output end of the micro-control unit. The input end of the rectification and filtering unit is connected to the output end of the isolation unit. The switching unit is connected in series in the power supply circuit of the solenoid valve, and the control end of the switching unit is connected to the output end of the rectification and filtering unit. When the micro-control unit has abnormal conditions such as crashing or damage and cannot work, at this time, the output port of the micro-control unit cannot flip, and the output signal is either always a high-level signal or always a low-level signal, and both are DC signals. Due to the characteristic of the isolation unit that it blocks DC and allows AC to pass through, the DC signal cannot pass through the isolation unit, the control end of the switching unit has no voltage, the switching unit is turned off, so that the power supply circuit of the solenoid valve is disconnected, the solenoid valve is closed, and the fluid is cut off, avoiding the problem that the micro-control unit is interfered and crashes, or suddenly damaged due to other reasons and cannot control the solenoid valve to close, resulting in the leakage of the controlled fluid, and improving the safety performance.

[0052] Embodiment 2

[0053] Figure 2 The circuit diagram of a solenoid valve drive circuit provided by the embodiment of the present utility model is shown. This embodiment is further refined on the basis of the foregoing Embodiment 1, and details the specific circuit structures of each unit of the solenoid valve drive circuit.

[0054] In some embodiments of the present utility model, as Figure 2 shown, the isolation unit 120 includes an isolation capacitor C1. The first electrode of the isolation capacitor C1 is connected to the output end of the micro-control unit 110, and the second electrode of the isolation capacitor C1 is connected to the input end of the rectification and filtering unit 130.

[0055] In some embodiments of the present utility model, as Figure 2 shown, the rectification and filtering unit 130 includes a first diode D1, a second diode D2, and a filtering capacitor C2. The anode of the first diode D1 is grounded, and the cathode of the first diode D1 is respectively connected to the output end of the isolation unit 120 (the second electrode of the isolation capacitor C1) and the anode of the second diode D2. The cathode of the second diode D2 is respectively connected to the control end of the switching unit 140 and the first electrode of the filtering capacitor C2, and the second electrode of the filtering capacitor C2 is grounded. As Figure 2 shown, the first diode D1 and the second diode D2 form a half-bridge rectification circuit, and the filtering capacitor C2 serves as a capacitor filtering circuit alone.

[0056] In some embodiments of the present utility model, as Figure 2As shown, the switch unit 140 includes an electronic switch tube Q1. Exemplarily, the electronic switch tube Q1 is a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET). In other embodiments of the present invention, the electronic switch tube Q1 can also be a triode, an Insulated Gate Bipolar Transistor, etc., which are not limited in the embodiments of the present invention. The first end of the electronic switch tube Q1 is connected to the first end of the solenoid valve 200. The second end of the solenoid valve 200 is connected to the power supply VDD of the solenoid valve 200. The second end of the electronic switch tube Q1 is grounded. The control end of the electronic switch tube Q1 is connected to the output end of the rectification and filtering unit 130 (the common node of the first electrode of the filter capacitor C2 and the cathode of the second diode D2). Exemplarily, the DC signal output by the rectification and filtering unit 130 is applied to the control end of the electronic switch tube Q1. When the voltage value of the DC signal reaches the threshold voltage of the electronic switch tube Q1, the electronic switch tube Q1 conducts, and the power supply circuit of the solenoid valve 200 is turned on. When the voltage at the control end of the electronic switch tube Q1 is lower than the threshold voltage or there is no voltage, the electronic switch tube Q1 turns off, and the power supply circuit of the solenoid valve 200 is disconnected.

[0057] Embodiment III

[0058] Figure 3 It is a circuit diagram of another solenoid valve drive circuit provided by the embodiment of the present invention. Based on the foregoing Embodiment II, this embodiment further improves the solenoid valve drive circuit.

[0059] In some embodiments of the present invention, as Figure 3 shown, the solenoid valve drive circuit further includes a signal amplification unit 150. The input end of the signal amplification unit 150 is connected to the output end of the micro control unit 110. The output end of the signal amplification unit 150 is connected to the input end of the isolation unit 120. The signal amplification unit 150 is used to amplify the alternating pulse signal. As described above, the voltage at the control end of the switch unit 140 needs to reach the threshold voltage to drive the switch unit 140 to conduct. Generally, the amplitude of the alternating pulse signal output by the micro control unit 110 is relatively low, and the voltage reaching the control end of the drive switch unit 140 is relatively low, making it difficult to directly drive the switch unit 140. If the amplitude of the alternating pulse signal output by the micro control unit 110 is increased, it will cause an increase in the load of the micro control unit 110, resulting in serious heating of the micro control unit 110. Therefore, in the embodiments of the present invention, a signal amplification unit 150 is added between the micro control unit 110 and the isolation unit 120 to amplify the low-amplitude alternating pulse signal output by the micro control unit 110 to obtain a high-amplitude alternating pulse signal, which can reduce the load of the micro control unit 110 and reduce the heat generation of the micro control unit 110.

[0060] In some embodiments of the present utility model, such as Figure 3 shown, the signal amplification unit 150 includes a first resistor R1, a second resistor R2, and a triode Q2. The first end of the first resistor R1 is connected to a reference voltage source VF of 12V. The second end of the first resistor R1 is respectively connected to the collector C of the triode Q2 and the input end of the isolation unit 120 (the first electrode of the isolation capacitor C1). The emitter E of the triode Q2 is grounded. The base B of the triode Q2 is connected to the output end of the micro control unit 110. The first end of the second resistor R2 is connected to the base B of the triode Q2, and the second end of the second resistor R2 is connected to the emitter E of the triode Q2. The second resistor R2 can provide a stable bias current, reduce the influence of temperature change on the performance of the triode Q2, and improve stability.

[0061] Exemplarily, the micro control unit 110 outputs an alternating pulse signal with a period of 1 millisecond and an amplitude of 5V. The alternating pulse signal is applied to the base B of the triode Q2. In the low-level half cycle (voltage value is 0V) of the alternating pulse signal, the triode Q2 is in the cut-off region, and the voltage of the collector B of the triode Q2 is the voltage divided by the first resistor R1, that is, the voltage of the reference voltage source VF, 12V. In the high-level half cycle (voltage value is 5V) of the alternating pulse signal, the triode Q2 is in the saturation region, the triode Q2 conducts, and the voltage of the collector B of the triode Q2 is the voltage divided by the triode Q2, approximately equal to 0V. Thus, the alternating pulse signal is amplified to obtain an alternating pulse signal with a period of 1 millisecond and an amplitude of 12V.

[0062] In some embodiments of the present utility model, such as Figure 3 shown, a resistor R3 is also connected in series between the micro control unit 110 and the input end (the base of the triode Q2) of the signal amplification unit 150. The resistor R3 plays a role in current limiting, avoiding damage to the signal amplification unit 150 (the triode Q2) caused by excessive current, and improving stability.

[0063] In some embodiments of the present utility model, such as Figure 3 shown, a resistor R4 is also connected in series between the output end (the collector C of the triode Q2) of the signal amplification unit 150 and the input end (the first electrode of the isolation capacitor C1) of the isolation unit 120. The resistor R4 plays a role in current limiting, avoiding damage to the isolation unit 120 (the isolation capacitor C1) caused by excessive current, and improving stability.

[0064] In some embodiments of the present utility model, such as Figure 3As shown, a resistor R5 is connected in series between the output terminal of the rectifying and filtering unit 130 (the common node of the first electrode of the filtering capacitor C2 and the cathode of the second diode D2) and the control terminal of the switching unit 140 (the control terminal of the electronic switching tube Q1). The resistor R5 plays a role in current limiting to prevent the switching unit 140 (electronic switching tube Q1) from being damaged due to excessive current, thereby improving stability.

[0065] In some embodiments of the present invention, as Figure 3 shown, a pull-down resistor R6 is connected in parallel to the control terminal of the switching unit 140 (the control terminal of the electronic switching tube Q1). The first end of the pull-down resistor R6 is connected to the control terminal of the switching unit 140 (the control terminal of the electronic switching tube Q1), and the second end of the pull-down resistor R6 is grounded. The pull-down resistor R6 is used to pull down the output voltage of the rectifying and filtering unit 130 to the driving voltage required by the control terminal of the switching unit 140 (the control terminal of the electronic switching tube Q1), preventing the control terminal of the switching unit 140 (the control terminal of the electronic switching tube Q1) from being broken down due to excessive voltage, and improving stability.

[0066] In some embodiments of the present invention, as Figure 3 shown, the solenoid valve drive circuit further includes a third diode D3. The anode of the third diode D3 is connected to the first end of the solenoid valve 200, and the cathode of the third diode D3 is connected to the second end of the solenoid valve 200. After the power supply circuit of the solenoid valve 200 is disconnected, a reverse electromotive force will be generated in the electromagnetic coil inside the solenoid valve 200, and this reverse electromotive force will damage other devices in the circuit (for example, the electronic switching tube Q1). In the embodiments of the present invention, the third diode D3 is connected in parallel across the solenoid valve 200. After the power supply circuit of the solenoid valve 200 is disconnected, the electromagnetic coil inside the solenoid valve 200 and the third diode D3 form a loop to consume the reverse electromotive force, preventing damage to other devices in the circuit and improving stability.

[0067] Embodiment 4

[0068] Figure 4 This is a circuit diagram of another solenoid valve drive circuit provided by the embodiments of the present invention. In this embodiment, on the basis of the foregoing Embodiment 3, the solenoid valve drive circuit is further improved.

[0069] In some embodiments of the present invention, as Figure 4As shown, the solenoid valve 200 includes an open-valve electromagnetic coil L1, a close-valve electromagnetic coil L2, an open-valve switch Q3, and a close-valve switch Q4. The open-valve electromagnetic coil L1 and the open-valve switch Q3 are connected in series to form an open-valve branch circuit, and the close-valve electromagnetic coil L2 and the close-valve switch Q4 form a close-valve branch circuit. The open-valve branch circuit and the close-valve branch circuit are connected in parallel in the power supply circuit of the solenoid valve 200. The control terminals of the open-valve switch Q3 and the close-valve switch Q4 are both connected to the micro control unit 110. Exemplarily, the first end of the open-valve electromagnetic coil L1 is connected to the power supply VDD, the second end of the open-valve electromagnetic coil L1 is connected to the first end of the open-valve switch Q3, the second end of the open-valve switch Q3 is connected to the first end of the switch unit 140 (the first end of the electronic switch tube Q1), the first end of the close-valve electromagnetic coil L2 is connected to the power supply VDD, the second end of the close-valve electromagnetic coil L2 is connected to the first end of the close-valve switch Q4, the second end of the close-valve switch Q4 is connected to the first end of the switch unit 140 (the first end of the electronic switch tube Q1), and the control terminals of the open-valve switch Q3 and the close-valve switch Q4 are both connected to the micro control unit 110 ( Figure 4 not shown in the figure). It should be noted that the control terminals of the open-valve switch Q3 and the close-valve switch Q4 can be matched with corresponding drive circuits to drive the open-valve switch Q3 and the close-valve switch Q4 to act, which will not be elaborated in the embodiments of the present invention.

[0070] The solenoid valve drive circuit further includes a solenoid valve detection unit 160. The input end of the solenoid valve detection unit 160 is connected to the close-valve branch circuit. Exemplarily, the input end of the solenoid valve detection unit 160 is connected to the second end of the close-valve switch Q4, and the output end of the solenoid valve detection unit 160 is connected to the micro control unit 110. The solenoid valve detection unit 160 is used to detect whether the close-valve branch circuit is open and feedback the detection result to the micro control unit 110.

[0071] Exemplarily, when the micro control unit 110 receives an open-valve instruction, in response to the open-valve instruction, it controls the output port to flip once every preset time period and outputs an alternating pulse signal to the isolation unit 120. Due to the characteristic of the isolation unit 120 of blocking direct current and passing alternating current, the alternating pulse signal can pass through the isolation unit 120 and be transmitted to the rectification and filtering unit 130. The rectification and filtering unit 130 rectifies and filters the alternating pulse signal to obtain a direct current signal and outputs it to the control terminal of the switch unit 140 to drive the switch unit 140 to conduct. At the same time, the micro control unit 110 sends a control signal to the open-valve switch Q3 to control the open-valve switch Q3 to conduct (at this time, the close-valve switch Q4 is turned off), the open-valve electromagnetic coil L1 is powered on (at this time, the close-valve electromagnetic coil L2 is not powered on), and the solenoid valve 200 is opened to allow the fluid to pass through.

[0072] When the micro - control unit 110 receives a valve - closing instruction, in response to the valve - closing instruction, it sends a control signal to the valve - closing switch Q4 to control the valve - closing switch Q4 to conduct. The valve - closing electromagnetic coil L2 is energized, the solenoid valve 200 closes, and the fluid is cut off.

[0073] After the micro - control unit 110 sends a control signal to control the conduction of the valve - closing switch Q4, if the solenoid valve detection unit 160 detects that the valve - closing branch is in an open - circuit state, it indicates that there are abnormalities in the valve - closing electromagnetic coil L2 and the connecting wire in the valve - closing branch. For example, the connecting wire is loose, which will cause the solenoid valve 200 to not be able to be normally closed through the valve - closing branch. At this time, the micro - control unit 110 receives the detection result of the solenoid valve detection unit 160 and outputs a DC level signal. Due to the characteristic of the isolation unit 120 to block DC and pass AC, the DC level signal cannot pass through the isolation unit 120, the control terminal of the switch unit 140 has no voltage, the switch unit 140 is turned off, so that the power supply circuit of the solenoid valve 200 is disconnected, the solenoid valve 200 closes, and the fluid is cut off, avoiding the problem that the micro - control unit 110 is interfered and crashes, or suddenly damaged due to other reasons and cannot control the solenoid valve to close, resulting in the leakage of the controlled fluid, and improving the safety.

[0074] When the micro - control unit 110 has abnormal conditions such as crashing or damage and cannot work, at this time, the output port of the micro - control unit 110 cannot flip, and the output signal is either always a high - level signal or always a low - level signal, both of which are DC signals. Due to the characteristic of the isolation unit 120 to block DC and pass AC, the DC signal cannot pass through the isolation unit 120, the control terminal of the switch unit 140 has no voltage, the switch unit 140 is turned off, so that the power supply circuit of the solenoid valve 200 is disconnected, the solenoid valve 200 closes, and the fluid is cut off, avoiding the problem that the micro - control unit 110 is interfered and crashes, or suddenly damaged due to other reasons and cannot control the solenoid valve to close, resulting in the leakage of the controlled fluid, and improving the safety.

[0075] In some embodiments of the present utility model, such as Figure 4As shown, the solenoid valve detection unit 160 includes a third resistor R7, a fourth resistor R8, and a fifth resistor R9. The first end of the third resistor R7 is connected to the valve closing branch. The second end of the third resistor R7 is connected to the first end of the fourth resistor R8 and the first end of the fifth resistor R9 respectively. The second end of the fourth resistor R8 is grounded, and the second end of the fifth resistor R9 is connected to the micro control unit 110. Exemplarily, after the micro control unit 110 sends a control signal to control the conduction of the valve closing switch Q4, under normal circumstances, the valve closing branch is conductive, and the solenoid valve detection unit 160 outputs a high-level signal (the voltage value is equal to the voltage division of the fourth resistor R8); if the valve closing branch is in an open circuit state, the solenoid valve detection unit 160 outputs a low-level signal (the voltage division of the fourth resistor R8 is 0V). Therefore, the micro control unit 110 can determine whether the valve closing branch is in an open circuit based on the level signal output by the solenoid valve detection unit 160.

[0076] Embodiment 5

[0077] Figure 5 The flowchart of a solenoid valve driving method provided by an embodiment of the present invention. This method can be applied to the solenoid valve driving circuit described in the foregoing Embodiment 1, Embodiment 2, or Embodiment 3, as Figure 5 shown, this solenoid valve driving method includes:

[0078] S11. The micro control unit responds to the valve opening instruction and outputs an alternating pulse signal.

[0079] Referring to Figure 1 、 2 、3, when the micro control unit 110 receives the valve opening instruction, in response to the valve opening instruction, it controls the output port to flip once every preset time period and outputs an alternating pulse signal. Due to the characteristic of the isolation unit 120 to block direct current and pass alternating current, the alternating pulse signal can pass through the isolation unit 120 and be transmitted to the rectifying and filtering unit 130. The rectifying and filtering unit 130 rectifies and filters the alternating pulse signal to obtain a direct current signal and outputs it to the control end of the switching unit 140 to drive the switching unit 140 to conduct, so that the power supply circuit of the solenoid valve 200 is connected, the solenoid valve 200 is opened, and the fluid can pass through.

[0080] S12. The micro control unit responds to the valve closing instruction and outputs a direct current level signal.

[0081] When the micro control unit 110 receives the valve closing instruction, in response to the valve closing instruction, it outputs a direct current signal (such as a direct current level signal). Due to the characteristic of the isolation unit 120 to block direct current and pass alternating current, the direct current signal cannot pass through the isolation unit 120, the control end of the switching unit 140 has no voltage, the switching unit 140 is turned off, so that the power supply circuit of the solenoid valve 200 is disconnected, the solenoid valve 200 is closed, and the fluid is cut off.

[0082] When the micro control unit 110 malfunctions, such as crashing or being damaged and cannot work, the output port of the micro control unit 110 cannot flip at this time, and the output signal is either always a high-level signal or always a low-level signal, both of which are DC signals. Due to the characteristic of the isolation unit 120 to block DC and pass AC, the DC signal cannot pass through the isolation unit 120, the control end of the switch unit 140 has no voltage, the switch unit 140 is turned off, so that the power supply circuit of the solenoid valve 200 is disconnected, the solenoid valve 200 is closed, the fluid is cut off, avoiding the micro control unit 110 from being interfered and crashing, or suddenly being damaged for other reasons and unable to control the solenoid valve to close, resulting in the leakage of the controlled fluid, and improving the safety.

[0083] Embodiment Six

[0084] Figure 6 The flowchart of another solenoid valve driving method provided by the embodiment of the present invention, this method can be applied to the solenoid valve driving circuit described in the foregoing Embodiment Four, as Figure 6 shown, this solenoid valve driving method includes:

[0085] S21. The micro control unit responds to the valve opening instruction, outputs an alternating pulse signal, and controls the valve opening switch to conduct.

[0086] Referring to Figure 4 , when the micro control unit 110 receives the valve opening instruction, in response to the valve opening instruction, it controls the output port to flip once every preset time period, and outputs an alternating pulse signal. Due to the characteristic of the isolation unit 120 to block DC and pass AC, the alternating pulse signal can pass through the isolation unit 120 and be transmitted to the rectifying and filtering unit 130. The rectifying and filtering unit 130 rectifies and filters the alternating pulse signal to obtain a DC signal and outputs it to the control end of the switch unit 140 to drive the switch unit 140 to conduct; at the same time, the micro control unit 110 sends a control signal to the valve opening switch Q3 to control the valve opening switch Q3 to conduct (at this time, the valve closing switch Q4 is turned off), the valve opening electromagnetic coil L1 is powered on (at this time, the valve closing electromagnetic coil L2 is not powered on), and the solenoid valve 200 is opened to allow the fluid to pass through.

[0087] S22. The micro control unit responds to the valve closing instruction and controls the valve closing switch to conduct.

[0088] When the micro control unit 110 receives the valve closing instruction, in response to the valve closing instruction, it sends a control signal to the valve closing switch Q4 to control the valve closing switch Q4 to conduct, the valve closing electromagnetic coil L2 is powered on, and the solenoid valve 200 is closed to cut off the fluid.

[0089] S23. When the micro control unit receives the feedback signal from the solenoid valve detection unit indicating that there is a break in the valve closing branch, it outputs a DC level signal.

[0090] After the micro control unit 110 sends a control signal to turn on the valve closing switch Q4, if the solenoid valve detection unit 160 detects that the valve closing branch is in an open circuit state, it indicates that there is an abnormality in the valve closing electromagnetic coil L2 and the connecting wire in the valve closing branch. For example, the connecting wire is loose, which will cause the solenoid valve 200 to not be normally closed through the valve closing branch. The solenoid valve detection unit 160 feeds back the detection result to the micro control unit 110. At this time, the micro control unit 110 receives the detection result of the solenoid valve detection unit 160 and outputs a DC level signal. Due to the characteristic of the isolation unit 120 to block DC and allow AC to pass through, the DC level signal cannot pass through the isolation unit 120, the control terminal of the switch unit 140 has no voltage, and the switch unit 140 is turned off, so that the power supply circuit of the solenoid valve 200 is disconnected, the solenoid valve 200 is closed, the fluid is cut off, avoiding the problem that the micro control unit 110 is interfered and crashes, or suddenly damaged due to other reasons and cannot control the solenoid valve to close, resulting in the leakage of the controlled fluid, and improving the safety.

[0091] When the micro control unit 110 malfunctions and cannot work, such as crashing or being damaged, at this time, the output port of the micro control unit 110 cannot flip, and the output signal is either always a high-level signal or always a low-level signal, both of which are DC signals. Due to the characteristic of the isolation unit 120 to block DC and allow AC to pass through, the DC signal cannot pass through the isolation unit 120, the control terminal of the switch unit 140 has no voltage, and the switch unit 140 is turned off, so that the power supply circuit of the solenoid valve 200 is disconnected, the solenoid valve 200 is closed, the fluid is cut off, avoiding the problem that the micro control unit 110 is interfered and crashes, or suddenly damaged due to other reasons and cannot control the solenoid valve to close, resulting in the leakage of the controlled fluid, and improving the safety.

[0092] Embodiment Seven

[0093] The present utility model further provides a gas appliance, including a gas valve and the solenoid valve drive circuit described in any of the foregoing embodiments. The solenoid valve drive circuit is used to drive the gas valve, and the solenoid valve drive circuit includes:

[0094] A micro control unit for emitting an alternating pulse signal;

[0095] An isolation unit, the input end of which is connected to the output end of the micro control unit for receiving the alternating pulse signal emitted by the micro control unit, and the isolation unit is used to isolate DC signals;

[0096] A rectification and filtering unit, the input end of which is connected to the output end of the isolation unit, and the rectification and filtering unit is used to rectify the alternating pulse signal and output a DC signal;

[0097] A switch unit, which is connected in series in the power supply circuit of the gas valve, and the control end of the switch unit is connected to the output end of the rectification and filtering unit.

[0098] Specifically, the solenoid valve driving circuit has been described in detail in the aforementioned embodiments, and the embodiments of the present utility model will not be described in detail here.

[0099] In the description of this article, it is necessary to understand that the terms "up", "down", "left", "right", and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0100] In the description of this specification, the description with reference to the terms "an embodiment", "example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0101] In addition, it should be understood that although this specification is described according to implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0102] The technical principle of the present invention is described above in combination with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the protection scope of the present invention in any way. Based on the explanations here, technicians in this field can think of other specific implementation methods of the present invention without creative work, and these methods will fall within the protection scope of the present invention.

Claims

1. A solenoid valve drive circuit, characterized in that, Comprising: A micro - control unit (110) for generating an alternating pulse signal; An isolation unit (120) whose input terminal is connected to the output terminal of the micro - control unit (110), for receiving the alternating pulse signal sent by the micro - control unit (110), and the isolation unit (120) is used for isolating DC signals; A rectification and filtering unit (130) whose input terminal is connected to the output terminal of the isolation unit (120), and the rectification and filtering unit (130) is used for rectifying and filtering the alternating pulse signal and outputting a DC signal; A switching unit (140) connected in series in the power supply circuit of the solenoid valve (200), and the control terminal of the switching unit (140) is connected to the output terminal of the rectification and filtering unit (130).

2. The solenoid valve drive circuit according to claim 1, characterized in that, The isolation unit (120) includes an isolation capacitor (C1), the first electrode of the isolation capacitor (C1) is connected to the output terminal of the micro - control unit (110), and the second electrode of the isolation capacitor (C1) is connected to the input terminal of the rectification and filtering unit (130).

3. The solenoid valve drive circuit according to claim 1, characterized in that, The rectification and filtering unit (130) includes a first diode (D1), a second diode (D2) and a filtering capacitor (C2). The anode of the first diode (D1) is grounded, the cathode of the first diode (D1) is respectively connected to the output terminal of the isolation unit (120) and the anode of the second diode (D2). The cathode of the second diode (D2) is respectively connected to the control terminal of the switching unit (140) and the first electrode of the filtering capacitor (C2), and the second electrode of the filtering capacitor (C2) is grounded.

4. The solenoid valve drive circuit according to claim 1, wherein The switching unit (140) includes an electronic switching tube (Q1). The first end of the electronic switching tube (Q1) is connected to the first end of the solenoid valve (200), the second end of the solenoid valve (200) is connected to the power supply of the solenoid valve (200), the second end of the electronic switching tube (Q1) is grounded, and the control terminal of the electronic switching tube (Q1) is connected to the output terminal of the rectification and filtering unit (130).

5. The solenoid valve drive circuit according to any one of claims 1-4, characterized in that It further includes a signal amplification unit (150). The input terminal of the signal amplification unit (150) is connected to the output terminal of the micro - control unit (110), and the output terminal of the signal amplification unit (150) is connected to the input terminal of the isolation unit (120). The signal amplification unit (150) is used for amplifying the alternating pulse signal.

6. The solenoid valve drive circuit according to claim 5, characterized in that The signal amplification unit (150) includes a first resistor (R1), a second resistor (R2), and a triode (Q2). The first end of the first resistor (R1) is connected to a reference voltage source. The second end of the first resistor (R1) is respectively connected to the collector of the triode (Q2) and the input end of the isolation unit (120). The emitter of the triode (Q2) is grounded. The base of the triode (Q2) is connected to the output end of the microcontrol unit (110). The first end of the second resistor (R2) is connected to the base of the triode (Q2), and the second end of the second resistor (R2) is connected to the emitter of the triode (Q2).

7. The solenoid valve drive circuit according to any one of claims 1-4, characterized in that, It further includes a third diode (D3). The anode of the third diode (D3) is connected to the first end of the solenoid valve (200). The first end of the solenoid valve (200) is connected to the switch unit (140). The second end of the solenoid valve (200) is connected to the power supply of the solenoid valve (200). The cathode of the third diode (D3) is connected to the second end of the solenoid valve (200).

8. The solenoid valve drive circuit according to any one of claims 1-4, characterized in that, The solenoid valve (200) includes an open-valve electromagnetic coil (L1), a close-valve electromagnetic coil (L2), an open-valve switch (Q3), and a close-valve switch (Q4). The open-valve electromagnetic coil (L1) and the open-valve switch (Q3) are connected in series to form an open-valve branch. The close-valve electromagnetic coil (L2) and the close-valve switch (Q4) form a close-valve branch. The open-valve branch and the close-valve branch are connected in parallel in the power supply circuit of the solenoid valve (200). The control ends of the open-valve switch (Q3) and the close-valve switch (Q4) are both connected to the microcontrol unit (110). The solenoid valve drive circuit further includes a solenoid valve detection unit (160). The input end of the solenoid valve detection unit (160) is connected to the close-valve branch. The output end of the solenoid valve detection unit (160) is connected to the microcontrol unit (110). The solenoid valve detection unit (160) is used to detect whether the close-valve branch is open and feedback the detection result to the microcontrol unit (110).

9. The solenoid valve drive circuit according to claim 8, wherein, The solenoid valve detection unit (160) includes a third resistor (R7), a fourth resistor (R8), and a fifth resistor (R9). The first end of the third resistor (R7) is connected to the close-valve branch. The second end of the third resistor (R7) is respectively connected to the first end of the fourth resistor (R8) and the first end of the fifth resistor (R9). The second end of the fourth resistor (R8) is grounded. The second end of the fifth resistor (R9) is connected to the microcontrol unit (110).

10. A gas appliance, characterized in that, It includes a gas valve and the solenoid valve drive circuit according to any one of claims 1-9. The solenoid valve drive circuit includes: A microcontrol unit for sending out an alternating pulse signal; An isolation unit. The input end of the isolation unit is connected to the output end of the microcontrol unit for receiving the alternating pulse signal sent out by the microcontrol unit. The isolation unit is used to isolate DC signals; A rectifying and filtering unit, the input end of the rectifying and filtering unit is connected to the output end of the isolation unit, and the rectifying and filtering unit is used to rectify the alternating pulse signal and output a direct current signal; A switching unit, the switching unit is connected in series in the power supply circuit of the gas valve, and the control end of the switching unit is connected to the output end of the rectifying and filtering unit.

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