A control drive circuit

Abstract

The present application relates to a kind of control drive circuit, comprising: timing circuit, switching control circuit, bypass circuit, voltage feedback regulation circuit and power conversion circuit.The present application can ensure electromagnetic coil or valve to open completely while automatically adjusting effective to reduce the heat quantity of coil during maintenance period, thereby reducing power consumption and heat consumption, prolong the service life of electromagnetic coil or valve in aerospace vehicle heat dissipation system Voltage width can be flexibly and conveniently adjusted, without microcontroller or processor, without high-power MOS tube, darlington tube or relay, without chopper control signal or pulse width modulation control signal, output voltage amplitude can be adjusted, voltage width can be set or automatically adjusted, without special heat dissipation design, small size of occupied space.The components used are all domestic commonly used components, and the circuit structure is simple, stable and easy to implement, which is conducive to practical promotion and application.

Description

Technical Field

[0001] This invention relates to the field of drive circuits, and more specifically to a control drive circuit. Background Technology

[0002] Electromagnetic coils and valves are increasingly widely used in aerospace vehicles, and their numbers are also increasing. Therefore, highly reliable and low-power drive circuits are essential to ensure the safe and reliable operation of electromagnetic coils and valves. The operation of electromagnetic coils or valves is mainly determined by the supply voltage or drive current. When the electromagnetic coil is not energized, the valve core is pressed against the valve seat by the spring force, thus closing the valve core. When the electromagnetic coil is energized, the armature, under the action of electromagnetic force, overcomes the spring force and drives the valve core to move, pressing it against the valve body limiting platform, thus opening its flow channel.

[0003] When the electromagnetic coil is initially energized, before the magnetic core or valve core opens, there is a large magnetic circuit gap between the coil and the iron core, resulting in high magnetic resistance. The coil needs to carry a sufficiently large current or voltage to generate a sufficiently large electromagnetic force to ensure that the moving iron core moves into position. However, after the valve opens, only a small current or voltage is needed to maintain the iron core's attraction state. If no circuit control measures are taken at this time, and the original large current or voltage is maintained, it will cause the coil and the power supply chip of the drive circuit to heat up, increase the energy consumption of the control circuit, reduce the valve's sealing and mechanical performance, shorten the valve body's life, and increase the failure rate.

[0004] Therefore, it is necessary to design a control drive circuit or electronic system with high reliability and reduced energy and heat consumption. At the moment when the electromagnetic coil or valve is turned from closed to open, a high voltage or current is provided to open the electromagnetic coil or valve. After it is fully opened, its supply voltage and operating current are reduced. In this way, while ensuring that the electromagnetic coil or valve is open, power consumption can be greatly reduced and the electromagnetic coil can be prevented from overheating, so that the control drive circuit can operate safely, stably and for a long time.

[0005] In existing technologies, one or more power switching devices such as MOSFETs, Darlington transistors, SCRs, and relays are often used as power actuators. Chopper or pulse-width modulation (PWM) signals are used to control these power devices to achieve solenoid valve current control. For example, patent CN1563691A discloses a valve drive circuit with signal processing circuitry. It uses bridge MOSFETs to build high-side and low-side drives, and uses a sampling resistor to measure the drive current and feed it back to the signal processing circuitry, thereby driving the solenoid valve. First, high-side drive MOSFETs typically employ a bootstrap boost method. During circuit switching, the coil freewheeling current generates a high surge voltage, which can easily cause the bootstrap boost circuit to malfunction. Second, to generate the pulse control signals for high-side and low-side drive, the signal processing circuit needs to perform real-time pulse width modulation (PWM) control based on the sampled current. This control method increases circuit complexity and has poor electromagnetic compatibility performance, making it unsuitable for electromagnetically sensitive environments. Finally, some solenoid valves have low solenoid coil inductance. Therefore, circuits using PWM to control high-side and low-side drive solenoid valves may experience large or even discontinuous current pulsations, posing a risk to the valve's safe holding and potentially leading to abnormal valve operation. Similar patents, CN101737551A and CN106122565A, also utilize PWM signals to control power drive circuits and MOSFETs to drive solenoid valves, exhibiting the same drawbacks.

[0006] The prior art patent CN106402458B discloses an energy-saving valve drive circuit with adjustable current. In principle, it controls the valve drive current by sampling current feedback and chopping to control the switching of the MOS transistor. This invention uses a three-terminal voltage regulator U1. The three-terminal voltage regulator is a linear voltage regulator. When the input voltage is high, resulting in a large input-output voltage difference, the three-terminal voltage regulator will overheat severely, and the thermal design of the circuit needs to be carefully considered. If the solenoid valve wants to achieve multiple on / off functions, it can only be done by turning the power supply on and off. There is no control signal or command to realize the on / off function of the solenoid valve.

[0007] The prior art patent with patent number CN106678422A discloses a drive circuit that uses a relay to control the solenoid valve for energy saving and cooling. However, the relay has problems such as being susceptible to interference and the contacts being prone to sticking together after being energized for a long time, resulting in low reliability. Therefore, it is a design that should be used with caution in the aerospace field. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a control drive circuit that can adjust the output voltage amplitude without using pulse width modulation signals, thus having better electromagnetic compatibility performance, ensuring that the electromagnetic coil or valve can be reliably maintained at low power after full operation, reducing heat consumption, improving reliability and extending lifespan.

[0009] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: a control drive circuit, comprising:

[0010] The device includes a power supply terminal and a drive output terminal. The power supply terminal is used to connect to a power signal, and the drive output terminal is used to connect to a drive voltage signal. The drive voltage signal includes a first drive voltage signal and a second drive voltage signal.

[0011] A timing circuit, electrically connected to the drive output terminal, is used to generate a voltage pulse signal with a preset time width under the action of the first drive voltage signal.

[0012] A switching control circuit is electrically connected to the drive output terminal and the timing circuit, and is used to output a control signal related to the preset time width under the action of the first drive voltage signal and the voltage pulse signal;

[0013] A bypass circuit, electrically connected between the switching control circuit and the power supply ground, is used to bypass the control signal within the preset time width and to cancel the bypass outside the preset time width of the control signal.

[0014] A voltage feedback regulation circuit, electrically connected to the drive output terminal and the bypass circuit, is used to sample and divide the first drive voltage signal to output a voltage feedback signal; wherein, the voltage feedback signal includes a first voltage feedback signal and a second voltage feedback signal, and does not participate in voltage division to output the first voltage feedback signal when the bypass circuit is bypassed, and participates in voltage division to output the second voltage feedback signal when the bypass circuit is unblocked;

[0015] A power conversion circuit is electrically connected to the power supply terminal, the drive output terminal, and the voltage feedback regulation circuit. It is used to convert the power supply signal to output the first drive voltage signal under the feedback regulation of the first voltage feedback signal, and to convert the power supply signal to output the second drive voltage signal under the feedback regulation of the second voltage feedback signal; wherein the first drive voltage signal is higher than the second drive voltage signal.

[0016] Based on the above technical solution, the present invention can be further improved as follows.

[0017] Furthermore, the timing circuit includes:

[0018] A first resistor and a first diode, one end of the first resistor is electrically connected to the drive output terminal, the other end of the first resistor is electrically connected to the negative terminal of the first diode, and the positive terminal of the first diode is electrically connected to the power supply ground;

[0019] A second resistor and a first capacitor, one end of the second resistor is electrically connected to the drive output terminal, the other end of the second resistor is electrically connected to one end of the first capacitor, and the other end of the first capacitor is electrically connected to the power supply ground;

[0020] The first comparator has its inverting input terminal electrically connected between the first resistor and the first diode, and its non-inverting input terminal electrically connected between the second resistor and the first capacitor.

[0021] A third resistor and a second capacitor are connected. One end of the third resistor is electrically connected to the drive output terminal, and the other end of the third resistor is electrically connected to one end of the second capacitor. The other end of the second capacitor is electrically connected to the power supply ground. The output terminal of the first comparator is connected between the third resistor and the second capacitor. The voltage pulse signal is output between the third resistor and the second capacitor and is electrically connected to the switching control circuit.

[0022] Furthermore, the switching control circuit includes:

[0023] A fourth resistor and a thermistor, one end of the fourth resistor is electrically connected to the drive output terminal, the other end of the fourth resistor is electrically connected to one end of the thermistor, and the other end of the thermistor is electrically connected to the power supply ground;

[0024] The second comparator has its inverting input electrically connected between the fourth resistor and the thermistor, its non-inverting input electrically connected to the timing circuit to receive the voltage pulse signal, and its output terminal outputting the control signal and being electrically connected to the bypass circuit.

[0025] Furthermore, the bypass circuit includes a fifth resistor, one end of which is electrically connected to the switching control circuit to receive the control signal, and the other end of which is electrically connected to the power ground.

[0026] The voltage feedback regulation circuit includes:

[0027] A sixth resistor and a seventh resistor, one end of the sixth resistor is electrically connected to the drive output terminal, the other end of the sixth resistor is electrically connected to one end of the seventh resistor, the other end of the seventh resistor is electrically connected to one end of the fifth resistor, and the voltage feedback signal is output between the sixth resistor and the seventh resistor and electrically connected to the power conversion circuit;

[0028] The third capacitor has one end electrically connected to the drive output terminal and the other end electrically connected between the sixth resistor and the seventh resistor.

[0029] Furthermore, the power conversion circuit includes:

[0030] The power conversion chip has a power input pin electrically connected to the power supply terminal, a feedback pin electrically connected to the voltage feedback regulation circuit to receive the voltage feedback signal, and an input ground pin and an output ground pin electrically connected to the power supply ground.

[0031] The fourth capacitor is electrically connected between the bootstrap pin and the switch pin of the power conversion chip.

[0032] The fifth capacitor is electrically connected between the power ground and the internal power pin of the power conversion chip;

[0033] An inductor, one end of which is electrically connected to the switching pin of the power conversion chip, and the other end outputs the drive voltage signal and is electrically connected to the drive output terminal;

[0034] The sixth capacitor has one end electrically connected between the inductor and the drive output terminal, and the other end electrically connected to the power supply ground.

[0035] Furthermore, it also includes a reverse voltage suppression circuit, which is electrically connected between the power conversion circuit and the drive output terminal; specifically, the reverse voltage suppression circuit includes a second diode, the negative terminal of which is electrically connected between the inductor and the drive output terminal, and the positive terminal of which is electrically connected to the power ground.

[0036] Furthermore, it also includes a power supply circuit, which is electrically connected between the power supply terminal and the power conversion circuit. Specifically, the power supply circuit includes a third diode, a seventh capacitor, and an eighth capacitor. The negative terminal of the third diode, one end of the seventh capacitor, and one end of the eighth capacitor are all electrically connected between the power supply terminal and the power input pin of the power conversion chip. The positive terminal of the third diode, the other end of the seventh capacitor, and the other end of the eighth capacitor are all electrically connected to the power ground.

[0037] Furthermore, it also includes an isolating switch circuit, which is electrically connected to the power conversion circuit; specifically, the isolating switch circuit includes:

[0038] The switch control signal terminal is used to connect switch control signals;

[0039] The optocoupler has its negative light-emitting electrode electrically connected to the isolation ground, its positive light-emitting electrode electrically connected to the switch control signal terminal to receive the switch control signal, and its light-receiving collector electrically connected to the power supply terminal.

[0040] The eighth resistor has one end electrically connected to the light-receiving and emitting electrode of the optocoupler, and the other end electrically connected to the enable pin of the power conversion chip.

[0041] The ninth resistor has one end electrically connected to the light-receiving and emitting electrode of the optocoupler, and the other end electrically connected to the power supply ground.

[0042] Furthermore, the isolating switch circuit also includes:

[0043] The tenth resistor is electrically connected between the switch control signal terminal and the positive light-emitting electrode of the optocoupler;

[0044] The ninth capacitor is electrically connected between the positive and negative light-emitting terminals of the optocoupler.

[0045] Furthermore, it also includes a unidirectional rectifier circuit, which is electrically connected between the drive output terminal and the timing circuit and the switching control circuit; specifically, the unidirectional rectifier circuit includes:

[0046] The fourth diode has its positive terminal electrically connected to the drive output terminal, and its negative terminal electrically connected to both the timing circuit and the switching control circuit.

[0047] The tenth capacitor has one end electrically connected to the negative terminal of the fourth diode and the other end electrically connected to the power supply ground.

[0048] Alternatively, the unidirectional rectifier circuit includes:

[0049] The fourth diode has its positive terminal electrically connected to the drive output terminal, and its negative terminal electrically connected to both the timing circuit and the switching control circuit.

[0050] The tenth capacitor has one end electrically connected to the negative terminal of the fourth diode and the other end electrically connected to the power supply ground.

[0051] The eleventh capacitor has one end electrically connected to the negative terminal of the fourth diode and the other end electrically connected to the power supply ground.

[0052] The beneficial effects of this invention are as follows: The control drive circuit of this invention can be applied to some devices that require high start-up voltage and low holding voltage, such as some electromagnetic coils or valves in aerospace vehicles. It can automatically adjust and effectively reduce the heat generated by the coil during the holding period while ensuring that the electromagnetic coil or valve is fully open, thereby reducing power consumption and heat dissipation, and extending the service life of the electromagnetic coil or valve in the aerospace vehicle's heat dissipation system. The start-up voltage amplitude is the start-up current, and the holding voltage is the holding current; both voltage widths can be flexibly and conveniently adjusted. Furthermore, this invention does not require a microcontroller or processor, high-power MOSFETs, Darlington transistors, or relays, nor does it require chopper control signals or pulse width modulation control signals. The output voltage amplitude is adjustable, and the voltage width can be set or automatically adjusted. No special heat dissipation design is required, and it occupies a small space. All components used are commonly used domestic components, and the circuit structure is simple, stable, and easy to implement, which is conducive to practical promotion and application. Attached Figure Description

[0053] Figure 1This is a structural block diagram of a control drive circuit according to the present invention;

[0054] Figure 2 This is another structural block diagram of a control drive circuit according to the present invention;

[0055] Figure 3 This is a schematic diagram of a control drive circuit according to the present invention;

[0056] Figure 4 This is a timing diagram of the operation of a control drive circuit according to the present invention. Detailed Implementation

[0057] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0058] like Figure 1 As shown, a control drive circuit includes:

[0059] The power supply terminal J_VIN and the drive output terminal VOUT are connected. The power supply terminal J_VIN is used to connect the power signal VIN_28V. The drive output terminal VOUT is used to connect the drive voltage signal VTJ. The drive voltage signal VTJ includes a first drive voltage signal and a second drive voltage signal.

[0060] Timing circuit 1 is electrically connected to the drive output terminal VOUT and is used to generate a voltage pulse signal with a preset time width under the action of the first drive voltage signal.

[0061] Switching control circuit 2 is electrically connected to the drive output terminal VOUT and the timing circuit 1, and is used to output a control signal FB_SW related to the preset time width under the action of the first drive voltage signal VTJ and the voltage pulse signal.

[0062] Bypass circuit 3 is electrically connected between the switching control circuit 2 and the power ground VIN_GND, and is used to bypass the control signal FB_SW within the preset time width and to cancel the bypass outside the preset time width of the control signal FB_SW.

[0063] The voltage feedback adjustment circuit 4 is electrically connected to the drive output terminal VOUT and the bypass circuit 3. It is used to sample and divide the first drive voltage signal to output a voltage feedback signal FB_SIG. The voltage feedback signal FB_SIG includes a first voltage feedback signal and a second voltage feedback signal. When the bypass circuit 3 is bypassed, it does not participate in the voltage division to output the first voltage feedback signal. When the bypass circuit 3 is unblocked, it participates in the voltage division to output the second voltage feedback signal.

[0064] The power conversion circuit 5 is electrically connected to the power supply terminal J_VIN, the drive output terminal VOUT, and the voltage feedback adjustment circuit 4. It is used to convert the power supply signal VIN_28V to output the first drive voltage signal under the feedback adjustment of the first voltage feedback signal, and to convert the power supply signal VIN_28V to output the second drive voltage signal under the feedback adjustment of the second voltage feedback signal; wherein the first drive voltage signal is higher than the second drive voltage signal.

[0065] This invention discloses a control drive circuit that can be applied to devices requiring high start-up voltage and low holding voltage, such as electromagnetic coils or valves in aerospace vehicles (the electromagnetic coils or valves are electrically connected to the drive output terminal VOUT). It can automatically adjust and effectively reduce the heat generated by the coil during the holding period while ensuring the electromagnetic coil or valve is fully open, thereby reducing power consumption and heat dissipation, and extending the service life of the electromagnetic coils or valves in the aerospace vehicle's heat dissipation system. The start-up voltage amplitude is the start-up current, and the holding voltage is the holding current; both voltage widths can be flexibly and conveniently adjusted.

[0066] In some embodiments, such as Figure 2 As shown, the control drive circuit of the present invention further includes:

[0067] The reverse voltage suppression circuit 6 is electrically connected between the power conversion circuit 5 and the drive output terminal VOUT, and is used to eliminate the back electromotive force.

[0068] Power supply circuit 7, which is electrically connected between the power supply terminal J_VIN and the power conversion circuit 5, is used to perform reverse connection protection, filtering and energy storage on the power signal VIN_28V connected to the power conversion circuit 5.

[0069] The isolating switch circuit 8 is electrically connected to the power conversion circuit 5 and is used to isolate the input switch control signal CTLSIG, and control the switching of the power conversion circuit 5 according to the switch control signal CTLSIG (i.e., control whether the power conversion circuit 5 outputs the drive voltage signal VTJ).

[0070] A unidirectional rectifier circuit 9 is electrically connected between the drive output terminal VOUT and the timing circuit 1 and the switching control circuit 2. It is used to rectify the drive voltage signal VTJ output by the drive output terminal VOUT and provide power to the timing circuit 1 and the switching control circuit 2 in a unidirectional power supply manner.

[0071] In some embodiments, such as Figure 3 As shown, the timing circuit 1 includes:

[0072] A first resistor R1 and a first diode D1 are connected. One end of the first resistor R1 is electrically connected to the drive output terminal VOUT, and the other end of the first resistor R1 is electrically connected to the negative terminal of the first diode D1. The positive terminal of the first diode D1 is electrically connected to the power ground VIN_GND.

[0073] The second resistor R2 and the first capacitor C1 are connected together. One end of the second resistor R2 is electrically connected to the drive output terminal VOUT, and the other end of the second resistor R2 is electrically connected to one end of the first capacitor C1. The other end of the first capacitor C1 is electrically connected to the power ground VIN_GND.

[0074] The first comparator U1A has its inverting input terminal electrically connected between the first resistor R1 and the first diode D1, and its non-inverting input terminal electrically connected between the second resistor R2 and the first capacitor C1.

[0075] A third resistor R3 and a second capacitor C2 are connected together. One end of the third resistor R3 is electrically connected to the drive output terminal VOUT, and the other end of the third resistor R3 is electrically connected to one end of the second capacitor C2. The other end of the second capacitor C2 is electrically connected to the power ground VIN_GND. The third resistor R3 and the second capacitor C2 are electrically connected to the output terminal of the first comparator U1A. The voltage pulse signal is output between the third resistor R3 and the second capacitor C2 and is electrically connected to the switching control circuit 2.

[0076] Timing circuit 1 is used to adjust the duration (preset time width) of the high voltage each time the electromagnetic coil or valve is opened. This high voltage provides a working current sufficient to ensure that the electromagnetic coil or valve is fully opened. This preset time width can be set and adjusted by the third resistor R3 and the second capacitor C2 used for timing. Increasing the resistance of the third resistor R3 and / or the capacitance of the second capacitor C2 will widen the preset time width of the voltage pulse signal, while decreasing the resistance of the third resistor R3 and / or the capacitance of the second capacitor C2 will narrow the preset time width of the voltage pulse signal. When the ambient temperature is 25℃, the preset time width T1≈0.707*R3*C2. The first diode D1 is specifically a Zener diode. The first diode D1 and the first resistor R1 provide a reference voltage, which is input to the inverting input of the first comparator U1A. The non-inverting input of the first comparator U1A is pulled up by the second resistor R2 and connected to the first capacitor C1. After the arrival of the valid switch control signal CTLSIG, since the voltage on the first capacitor C1 cannot change abruptly, the voltage at the non-inverting input of the first comparator U1A is less than the voltage at the inverting input. Therefore, the non-inverting comparison of the first comparator U1A initially outputs a low level to allow the second capacitor C2 to fully discharge. Then, as time progresses, the voltage of the first capacitor C1 gradually increases until the voltage at the non-inverting input of the first comparator U1A exceeds the voltage at the inverting input. Thus, the non-inverting comparison of the first comparator U1A outputs a high level, serving as the enable signal for the subsequent charging of the third resistor R3 and the second capacitor C2. The function of the first comparator U1A is to ensure that the third resistor R3 and the second capacitor C2 start charging from 0 voltage after the power supply stabilizes after the arrival of the valid switch control signal CTLSIG, thus eliminating charging errors. After passing through timing circuit 1, a voltage pulse signal with a preset time width adjustable will be generated and sent to the subsequent switching control circuit 2.

[0077] In some embodiments, such as Figure 3 As shown, the switching control circuit 2 includes:

[0078] A fourth resistor R4 and a thermistor RT are connected. One end of the fourth resistor R4 is electrically connected to the drive output terminal VOUT, and the other end of the fourth resistor R4 is electrically connected to one end of the thermistor RT. The other end of the thermistor RT is electrically connected to the power ground VIN_GND.

[0079] The second comparator U1B has its inverting input terminal electrically connected between the fourth resistor R4 and the thermistor RT, its non-inverting input terminal electrically connected to the timing circuit 1 to receive the voltage pulse signal, and its output terminal outputs the control signal FB_SW and is electrically connected to the bypass circuit 3.

[0080] The switching control circuit 2 implements the switching control of the feedback regulation resistor in the power conversion. In the switching control circuit 2, the thermistor RT is specifically an NTC thermistor. The fourth resistor R4 and the thermistor RT provide a voltage related to the ambient temperature to the inverting input of the second comparator U1B. The second comparator U1B compares the input non-inverting voltage and the inverting voltage and outputs a control signal related to a preset time width to control the bypass circuit 3. Within the preset time width, the bypass circuit 3 is bypassed; outside the preset time width, the bypassing of the bypass circuit 3 is canceled, and the bypass circuit 3 participates in the feedback regulation control. When the ambient temperature rises, the voltage input to the inverting input of the second comparator U1B decreases due to the voltage division effect of the fourth resistor R4 and the thermistor RT. This automatically narrows the preset time width. Conversely, when the ambient temperature decreases, the voltage input to the inverting input of the second comparator U1B increases due to the voltage division effect of the fourth resistor R4 and the thermistor RT. This automatically widens the preset time width. This achieves the automatic adjustment function of shortening the turn-on time and reducing heat consumption when the ambient temperature rises.

[0081] In some embodiments, such as Figure 3 As shown, the bypass circuit 3 includes a fifth resistor R5. One end of the fifth resistor R5 is electrically connected to the switching control circuit 2 to receive the control signal FB_SW, and the other end of the fifth resistor R5 is electrically connected to the power ground VIN_GND.

[0082] The voltage feedback regulation circuit 4 includes:

[0083] The sixth resistor R6 and the seventh resistor R7 are connected together. One end of the sixth resistor R6 is electrically connected to the drive output terminal VOUT, and the other end of the sixth resistor R6 is electrically connected to one end of the seventh resistor R7. The other end of the seventh resistor R7 is electrically connected to one end of the fifth resistor R5. The voltage feedback signal FB_SIG is output between the sixth resistor R6 and the seventh resistor R7 and is electrically connected to the power conversion circuit 5.

[0084] The third capacitor C3 has one end electrically connected to the drive output terminal VOUT, and the other end electrically connected between the sixth resistor R6 and the seventh resistor R7.

[0085] The voltage feedback regulation circuit 4 samples and feeds back the first driving voltage signal to regulate the high and low voltages of the output driving voltage signal in a closed loop. To adjust the dynamic performance of the output and prevent overshoot and oscillation, the voltage feedback regulation circuit 4 includes a third capacitor C3 for feedback regulation to improve dynamic characteristics. When the control signal FB_SW output by the switching control circuit 2 is high, the voltage feedback signal FB_SIG is determined by the voltage division between the sixth resistor R6 and the seventh resistor R7. The fifth resistor R5 is "bypassed" under the action of the switching control circuit 2. When the control signal FB_SW output by the switching control circuit 2 is low, the voltage feedback signal FB_SIG is determined by the voltage division between the sixth resistor R6, the seventh resistor R7, and the fifth resistor R5. The fifth resistor R5 participates in voltage feedback control under the action of the switching control circuit 2. The sixth resistor R6 can be composed of multiple independent resistors connected in series. This is to reduce the value of a single resistor and thus improve the accuracy of the resistor. Connecting multiple resistors in series also allows for more flexible and convenient configuration of resistor values ​​to adapt to different output voltage amplitudes.

[0086] In some embodiments, such as Figure 3 As shown, the power conversion circuit 5 includes:

[0087] The power conversion chip U2 has its power input pin VIN electrically connected to the power supply terminal J_VIN, its feedback pin FB electrically connected to the voltage feedback regulation circuit 4 to receive the voltage feedback signal FB_SIG, and its input ground pin PGND and output ground pin AGND electrically connected to the power ground VIN_GND.

[0088] The fourth capacitor C4 is electrically connected between the bootstrap pin BOOT and the switch pin SW of the power conversion chip U2.

[0089] The fifth capacitor C5 is electrically connected between the power ground VIN_GND and the internal power supply pin VCC of the power conversion chip U2;

[0090] One end of the inductor L is electrically connected to the switch pin SW of the power conversion chip U2, and the other end outputs the drive voltage signal VTJ and is electrically connected to the drive output terminal VOUT.

[0091] The sixth capacitor C6 has one end electrically connected between the inductor L and the drive output terminal VOUT, and the other end electrically connected to the power ground VIN_GND.

[0092] The power conversion circuit 5 converts the power signal VIN_28V into a high voltage (i.e., the first drive voltage signal) required by the electromagnetic coil or valve to provide the turning current and a low voltage (i.e., the second drive voltage signal) to provide the holding current. The fourth capacitor C4 provides the bootstrap voltage for use within the power conversion chip U2, and the fifth capacitor C5 performs internal voltage filtering. The inductor L and the sixth capacitor C6 smooth and filter the voltage output from the power conversion chip U2, reducing output voltage ripple and simultaneously providing energy storage for the load.

[0093] In some embodiments, such as Figure 3 As shown, the reverse voltage suppression circuit 6 includes a second diode D2. The negative terminal of the second diode D2 is electrically connected between the inductor L and the drive output terminal VOUT, and the positive terminal of the second diode D2 is electrically connected to the power ground VIN_GND.

[0094] When the electromagnetic coil is turned off, a very high back electromotive force voltage is generated. The function of the back voltage suppression circuit 6 is to protect the circuit by suppressing and eliminating the back electromotive force to prevent the back electromotive force voltage from damaging the drive control circuit.

[0095] In some embodiments, such as Figure 3 As shown, the power supply circuit 7 includes a third diode D3, a seventh capacitor C7, and an eighth capacitor C8. The negative terminal of the third diode D3, one end of the seventh capacitor C7, and one end of the eighth capacitor C8 are all electrically connected between the power supply terminal J_VIN and the power input pin of the power conversion chip U2. The positive terminal of the third diode D3, the other end of the seventh capacitor C7, and the other end of the eighth capacitor C8 are all electrically connected to the power ground VIN_GND.

[0096] Power supply circuit 7 is used for reverse connection protection, filtering, and energy storage. The third diode D3 prevents the input power supply from being reversed, effectively protecting the circuit from damage due to reverse connection. The seventh capacitor C7 and the eighth capacitor C8 are used for filtering and energy storage, respectively.

[0097] In some embodiments, such as Figure 3 As shown, the isolating switch circuit 8 includes:

[0098] The switch control signal terminal I / O is used to connect the switch control signal CTLSIG.

[0099] Optical coupler U3 has its negative light-emitting electrode electrically connected to isolation ground DGND, its positive light-emitting electrode electrically connected to the switch control signal terminal I / O to access the switch control signal CTLSIG, and its light-receiving collector electrically connected to the power supply terminal J_VIN.

[0100] The eighth resistor R8 is electrically connected at one end to the light-receiving and emitting electrode of the optocoupler U3, and at the other end to the enable pin EN / SYNC of the power conversion chip U2.

[0101] The ninth resistor R9 is electrically connected at one end to the light-receiving and emitting electrode of the optocoupler U3, and at the other end to the power ground VIN_GND.

[0102] In some embodiments, such as Figure 3 As shown, the isolating switch circuit further includes:

[0103] The tenth resistor R10 is electrically connected between the switch control signal terminal I / O and the positive light-emitting electrode of the optocoupler U3;

[0104] The ninth capacitor C9 is electrically connected between the positive and negative light-emitting terminals of the optocoupler U3.

[0105] To ensure electromagnetic compatibility performance and protect the circuit, the switch control signal CTLSIG is isolated using optocoupler U3. The tenth resistor R10 limits the input diode of optocoupler U3 to prevent damage from excessive current. The ninth capacitor C9 filters out pulse interference voltage on the switch control signal CTLSIG. The ninth resistor R9 is a pull-down resistor. When the switch control signal CTLSIG is low, the enable pin EN / SYNC of power converter chip U2 is pulled low, and power converter circuit 5 has no output (i.e., the switch pin SW of power converter chip U2 has no output). When the switch control signal CTLSIG is high, the enable pin EN / SYNC of power converter chip U2 is pulled high through the eighth resistor R8, and power converter circuit 5 has voltage output (i.e., the switch pin SW of power converter chip U2 has output). The switch control signal CTLSIG thus functions as a switch.

[0106] In some embodiments, such as Figure 3 As shown, the unidirectional rectifier circuit 9 includes:

[0107] The positive terminal of the fourth diode D4 is electrically connected to the drive output terminal VOUT, and the negative terminal is electrically connected to the timing circuit 1 and the switching control circuit 2 respectively.

[0108] The tenth capacitor C10 is electrically connected at one end to the negative terminal of the fourth diode D4, and at the other end to the power ground VIN_GND.

[0109] Alternatively, the unidirectional rectifier circuit 9 includes:

[0110] The positive terminal of the fourth diode D4 is electrically connected to the drive output terminal VOUT, and the negative terminal is electrically connected to the timing circuit 1 and the switching control circuit 2 respectively.

[0111] The tenth capacitor C10 is electrically connected at one end to the negative terminal of the fourth diode D4, and at the other end to the power ground VIN_GND.

[0112] The eleventh capacitor C11 is electrically connected at one end to the negative terminal of the fourth diode D4, and at the other end to the power ground VIN_GND.

[0113] In the unidirectional rectifier circuit 9, the fourth diode D4 provides a unidirectional power supply channel and rectification function for the subsequent timing circuit 1 and switching control circuit 2. Together with the tenth capacitor C10, it makes the voltage fluctuation or ripple of the timing circuit 1 smaller and the timing more accurate.

[0114] The eleventh capacitor C11 serves to decouple and filter the power supply of the first comparator U1A in timing circuit 1 and the second comparator U1B in switching control circuit 2.

[0115] Figure 4 This is a timing diagram illustrating the operation of a control drive circuit according to the present invention. Figure 4 As shown: When the switch control signal CTLSIG is low (standby), the entire circuit has no output voltage or current. When the switch control signal CTLSIG is high, the entire time width is T1+T2. The entire circuit will first output a high voltage (first drive voltage signal) for a time width of T1, then output a low voltage (second drive voltage signal) for a time width of T2, corresponding to the turn-on current for a time width of T1, and then output a holding current for a time width of T2. T1 is a preset time width that can be adjusted by the third resistor R3 and the second capacitor C2. The time width of T2 depends on the effective high-level width of the switch control signal CTLSIG. In the next cycle, the switch control signal CTLSIG goes high again, repeating the previous process. The output voltage amplitude is configured and adjusted by the voltage feedback adjustment circuit.

[0116] This invention requires no microcontroller or processor, no high-power MOSFETs, Darlington transistors, or relays, and no chopper control signals or pulse width modulation (PWM) control signals. The output voltage amplitude is adjustable, and the voltage width can be set or automatically adjusted. Only a high- and low-level switching control signal CTLSIG is needed to achieve continuous multiple on / off control of the electromagnetic coil or valve. The switching control signal CTLSIG is electrically isolated from the power supply. The circuit requires only a single power supply with reverse connection protection, requires no special heat dissipation design, and occupies a small space. All components used are commonly available domestically produced parts, and the circuit structure is simple, stable, and easy to implement, which is conducive to practical promotion and application.

[0117] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A control drive circuit, characterized in that, include: The device includes a power supply terminal and a drive output terminal. The power supply terminal is used to connect to a power signal, and the drive output terminal is used to connect to a drive voltage signal. The drive voltage signal includes a first drive voltage signal and a second drive voltage signal. A timing circuit, electrically connected to the drive output terminal, is used to generate a voltage pulse signal with a preset time width under the action of the first drive voltage signal. A switching control circuit is electrically connected to the drive output terminal and the timing circuit, and is used to output a control signal related to the preset time width under the action of the first drive voltage signal and the voltage pulse signal; A bypass circuit, electrically connected between the switching control circuit and the power supply ground, is used to bypass the control signal within the preset time width and to cancel the bypass outside the preset time width of the control signal. A voltage feedback regulation circuit, electrically connected to the drive output terminal and the bypass circuit, is used to sample and divide the first drive voltage signal to output a voltage feedback signal; wherein, the voltage feedback signal includes a first voltage feedback signal and a second voltage feedback signal, and does not participate in voltage division to output the first voltage feedback signal when the bypass circuit is bypassed, and participates in voltage division to output the second voltage feedback signal when the bypass circuit is unblocked; A power conversion circuit is electrically connected to the power supply terminal, the drive output terminal, and the voltage feedback regulation circuit. It is used to convert the power supply signal to output the first drive voltage signal under the feedback regulation of the first voltage feedback signal, and to convert the power supply signal to output the second drive voltage signal under the feedback regulation of the second voltage feedback signal; wherein the first drive voltage signal is higher than the second drive voltage signal.

2. The control drive circuit according to claim 1, characterized in that, The timing circuit includes: A first resistor and a first diode, one end of the first resistor is electrically connected to the drive output terminal, the other end of the first resistor is electrically connected to the negative terminal of the first diode, and the positive terminal of the first diode is electrically connected to the power supply ground; A second resistor and a first capacitor, one end of the second resistor is electrically connected to the drive output terminal, the other end of the second resistor is electrically connected to one end of the first capacitor, and the other end of the first capacitor is electrically connected to the power supply ground; The first comparator has its inverting input terminal electrically connected between the first resistor and the first diode, and its non-inverting input terminal electrically connected between the second resistor and the first capacitor. A third resistor and a second capacitor are connected. One end of the third resistor is electrically connected to the drive output terminal, and the other end of the third resistor is electrically connected to one end of the second capacitor. The other end of the second capacitor is electrically connected to the power supply ground. The output terminal of the first comparator is connected between the third resistor and the second capacitor. The voltage pulse signal is output between the third resistor and the second capacitor and is electrically connected to the switching control circuit.

3. The control drive circuit according to claim 1, characterized in that, The switching control circuit includes: A fourth resistor and a thermistor, one end of the fourth resistor is electrically connected to the drive output terminal, the other end of the fourth resistor is electrically connected to one end of the thermistor, and the other end of the thermistor is electrically connected to the power supply ground; The second comparator has its inverting input electrically connected between the fourth resistor and the thermistor, its non-inverting input electrically connected to the timing circuit to receive the voltage pulse signal, and its output terminal outputting the control signal and being electrically connected to the bypass circuit.

4. The control drive circuit according to claim 1, characterized in that, The bypass circuit includes a fifth resistor, one end of which is electrically connected to the switching control circuit to receive the control signal, and the other end of which is electrically connected to the power ground. The voltage feedback regulation circuit includes: A sixth resistor and a seventh resistor, one end of the sixth resistor is electrically connected to the drive output terminal, the other end of the sixth resistor is electrically connected to one end of the seventh resistor, the other end of the seventh resistor is electrically connected to one end of the fifth resistor, and the voltage feedback signal is output between the sixth resistor and the seventh resistor and electrically connected to the power conversion circuit; The third capacitor has one end electrically connected to the drive output terminal and the other end electrically connected between the sixth resistor and the seventh resistor.

5. The control drive circuit according to claim 1, characterized in that, The power conversion circuit includes: The power conversion chip has a power input pin electrically connected to the power supply terminal, a feedback pin electrically connected to the voltage feedback regulation circuit to receive the voltage feedback signal, and an input ground pin and an output ground pin electrically connected to the power supply ground. The fourth capacitor is electrically connected between the bootstrap pin and the switch pin of the power conversion chip. The fifth capacitor is electrically connected between the power ground and the internal power pin of the power conversion chip; An inductor, one end of which is electrically connected to the switching pin of the power conversion chip, and the other end outputs the drive voltage signal and is electrically connected to the drive output terminal; The sixth capacitor has one end electrically connected between the inductor and the drive output terminal, and the other end electrically connected to the power supply ground.

6. The control drive circuit according to claim 5, characterized in that, It also includes a reverse voltage suppression circuit, which is electrically connected between the power conversion circuit and the drive output terminal; specifically, the reverse voltage suppression circuit includes a second diode, the negative terminal of which is electrically connected between the inductor and the drive output terminal, and the positive terminal of which is electrically connected to the power ground.

7. The control drive circuit according to claim 5, characterized in that, It also includes a power supply circuit, which is electrically connected between the power supply terminal and the power conversion circuit. Specifically, the power supply circuit includes a third diode, a seventh capacitor, and an eighth capacitor. The negative terminal of the third diode, one end of the seventh capacitor, and one end of the eighth capacitor are all electrically connected between the power supply terminal and the power input pin of the power conversion chip. The positive terminal of the third diode, the other end of the seventh capacitor, and the other end of the eighth capacitor are all electrically connected to the power ground.

8. The control drive circuit according to claim 5, characterized in that, It also includes an isolating switch circuit, which is electrically connected to the power conversion circuit; specifically, the isolating switch circuit includes: The switch control signal terminal is used to connect switch control signals; The optocoupler has its negative light-emitting electrode electrically connected to the isolation ground, its positive light-emitting electrode electrically connected to the switch control signal terminal to receive the switch control signal, and its light-receiving collector electrically connected to the power supply terminal. The eighth resistor has one end electrically connected to the light-receiving and emitting electrode of the optocoupler, and the other end electrically connected to the enable pin of the power conversion chip. The ninth resistor has one end electrically connected to the light-receiving and emitting electrode of the optocoupler, and the other end electrically connected to the power supply ground.

9. The control drive circuit according to claim 8, characterized in that, The isolating switch circuit also includes: The tenth resistor is electrically connected between the switch control signal terminal and the positive light-emitting electrode of the optocoupler; The ninth capacitor is electrically connected between the positive and negative light-emitting terminals of the optocoupler.

10. The control drive circuit according to claim 1, characterized in that, It also includes a unidirectional rectifier circuit, which is electrically connected between the drive output terminal and the timing circuit and the switching control circuit, and the timing circuit and the switching control circuit are electrically connected to the drive output terminal through the unidirectional rectifier circuit. Specifically, the unidirectional rectifier circuit includes: The fourth diode has its positive terminal electrically connected to the drive output terminal, and its negative terminal electrically connected to both the timing circuit and the switching control circuit. The tenth capacitor has one end electrically connected to the negative terminal of the fourth diode and the other end electrically connected to the power supply ground. Alternatively, the unidirectional rectifier circuit includes: The fourth diode has its positive terminal electrically connected to the drive output terminal, and its negative terminal electrically connected to both the timing circuit and the switching control circuit. The tenth capacitor has one end electrically connected to the negative terminal of the fourth diode and the other end electrically connected to the power supply ground. The eleventh capacitor has one end electrically connected to the negative terminal of the fourth diode and the other end electrically connected to the power supply ground.

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