A solenoid valve drive circuit device and its working method

Abstract

The present invention discloses a solenoid valve drive circuit device and its working method. The power supply module is connected to all other components. The output end of the MCU interface module is connected to the input end of the drive module. The input ends of the feedback acquisition module and the current acquisition module are both connected to the output end of the drive module. The output ends of the feedback acquisition module and the current acquisition module are both connected to the input end of the MCU interface module. The MCU interface module is connected to an MCU. It can effectively monitor voltage faults and overcurrent faults in the circuit without adding excessive cost and space.

Description

Technical Field

[0001] The present invention belongs to the field of solenoid valves and relates to a solenoid valve drive circuit device and its working method. Background Art

[0002] Traditional solenoid valve drive circuits are generally half-bridge drives or full-bridge drives. Although with the development of technology, there are already many bridge drive chips on the market, which perfectly solve the dead zone problem and avoid burning out the MOS devices in the drive circuit. However, the bridge drive circuit composed of drive chips, MOS, and many resistors and capacitors is complex in design and difficult to debug. For voltage faults or overcurrent faults in the circuit, it cannot be timely feedback, which easily leads to the burning out of the backend devices. If a low-cost MOS is selected, the drive voltage is small, the on-resistance of the MOS transistor is large, and the heat generation is high, and sacrifices need to be made in terms of power consumption, heat dissipation, and volume; if a MOS transistor with a relatively small on-resistance is selected, the cost is relatively high. Moreover, regardless of whether a low-cost or high-cost MOS transistor is selected, each drive circuit requires at least one drive chip and one MOS transistor. In many applications, multiple solenoid valves need to be driven simultaneously, and many identical drive circuits must be used to form a complex MOS array, which will also double the cost and space. Summary of the Invention

[0003] The purpose of the present invention is to overcome the above-mentioned disadvantages of the prior art and provide a solenoid valve drive circuit device and its working method, which can effectively monitor voltage faults and overcurrent faults in the circuit without increasing too much cost and space.

[0004] To achieve the above purpose, the present invention adopts the following technical solutions:

[0005] A solenoid valve drive circuit device includes a power supply module, an MCU interface module, a drive module, a feedback acquisition module, and a current acquisition module;

[0006] The power supply module is connected to all other devices. The output end of the MCU interface module is connected to the input end of the drive module. The input ends of the feedback acquisition module and the current acquisition module are both connected to the output end of the drive module. The output ends of the feedback acquisition module and the current acquisition module are both connected to the input end of the MCU interface module; the MCU interface module is connected to an MCU;

[0007] The power supply module is used for supplying power to the devices in the circuit and providing drive current for the drive interface;

[0008] The drive module is used to drive the solenoid valve, convert the drive signal sent by the MCU from TTL level to a level with driving ability to drive the solenoid valve;

[0009] The feedback acquisition module is used to acquire the drive signal, and then transmit the acquired feedback signal back to the MCU through the MCU interface module. The MCU can compare the drive signal and the feedback signal to confirm whether there is a fault in the circuit;

[0010] The current acquisition module is used to acquire the drive current in real time, convert the current signal into a voltage signal and feedback it to the MCU through the MCU interface module;

[0011] The MCU interface module mainly completes the issuance of drive commands and the acquisition of feedback signals, and is used to complete the data interaction between the MCU and the drive circuit; The MCU is used to compare the drive signal and the feedback signal to confirm whether there is a fault in the circuit, and monitor the drive current to judge whether there is an overcurrent phenomenon.

[0012] Preferably, the drive circuit uses a power electronic switch chip.

[0013] Preferably, the feedback acquisition module includes a comparator U3. The two input terminals of the comparator U3 are respectively connected to the output terminal of the drive module and the output terminal of the power supply module, and the output terminal of the comparator U3 is connected to the input terminal of the MCU interface module.

[0014] Preferably, the current acquisition module includes a current sampling conversion circuit, a conditioning circuit, a follower circuit, an isolation amplifier and a detection circuit connected in sequence.

[0015] Furthermore, the current sampling conversion circuit includes a sampling resistor and a capacitor connected in parallel.

[0016] Furthermore, both the conditioning circuit and the follower circuit use amplifiers.

[0017] Furthermore, the detection circuit includes two amplifiers connected in series, and a diode is connected in series between the two amplifiers.

[0018] Preferably, an isolation buffer module is provided between the MCU interface module and the drive module, the feedback acquisition module and the current acquisition module.

[0019] Preferably, a power supply monitoring module is provided between the power supply module and the MCU interface module. The power supply monitoring module is used to monitor the voltage of the power supply in the circuit for power failure alarm.

[0020] A working method of the solenoid valve drive circuit device according to any one of the above, the power supply module supplies power to the remaining devices in the circuit, the MCU sends a drive signal to the drive module through the MCU interface module, the drive module drives the solenoid valve to work, the feedback acquisition module acquires the drive signal, and then the acquired feedback signal is sent back to the MCU through the MCU interface module. The MCU confirms whether there is a fault in the circuit by comparing the drive signal and the feedback signal; the current acquisition module acquires the drive current in real time, then converts the current signal into a voltage signal and feeds it back to the MCU through the MCU interface module. The MCU judges whether there is an overcurrent phenomenon by monitoring the drive current. If there is a fault or an overcurrent phenomenon in the circuit, the MCU sends a stop signal to the drive module through the MCU interface module.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The circuit of the present invention has low power consumption. There is no need for heat-generating devices such as MOS in the circuit, and there is no need to use a radiator to dissipate heat from the circuit components, reducing the structural space and cost; the circuit is simple, easy to debug, has a low failure rate, and low cost; it can effectively monitor voltage faults and overcurrent faults in the circuit without adding too much cost and space; the circuit of the present invention is small in size and can be used in various commercial and industrial technical fields such as rail transit, automotive electronics, medical electronics, and intelligent control.

[0023] Further, the isolation buffer module completes the isolation between the internal circuit and the drive circuit, reducing the drive current pressure of the MCU and avoiding the mutual influence between the two ground systems.

[0024] Further, the power supply monitoring module can monitor the voltage of the power supply in the circuit for power supply fault alarm. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is the overall architecture diagram of the present invention;

[0026] Figure 2 is the core circuit schematic diagram of the power supply monitoring module of the present invention;

[0027] Figure 3 is the circuit diagram of the drive module of the present invention;

[0028] Figure 4 is the circuit diagram of the feedback acquisition module of the present invention;

[0029] Figure 5 is the circuit diagram of the current acquisition module of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0031] It should be noted that the terms "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to the directions in the drawings, and the terms "inner" and "outer" respectively refer to the directions towards or away from the geometric center of a specific component.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0033] As Figure 1 shown, the solenoid valve drive circuit device of the present invention includes a power supply module, a power supply monitoring module, an MCU interface module, an isolation buffer module, a drive module, a feedback acquisition module, and a current acquisition module.

[0034] The output end of the power supply module is connected to all other devices, and the input end of the power supply module is connected to a power supply interface; the input end of the power supply monitoring module is connected to the power supply module, and the output end of the power supply monitoring module is connected to the input end of the MCU interface module; the output end of the MCU interface module is respectively connected to the input end of the power supply module and the input end of the drive module; the output end of the MCU interface module is connected to the input end of the drive module, and the MCU interface module is connected to an MCU; the input ends of the feedback acquisition module and the current acquisition module are both connected to the output end of the drive module, and the output ends of the feedback acquisition module and the current acquisition module are both connected to the input end of the MCU interface module; the output end of the drive module is connected to a drive interface. An isolation buffer module is provided between the MCU interface module and the drive module, the feedback acquisition module, and the current acquisition module.

[0035] Among them, the power supply module mainly completes the isolation of the power supply and the power supply of the devices in the circuit, and provides drive current for the drive interface; the power supply monitoring module is mainly used to monitor the voltage of the main power supply in the circuit for power failure alarm; the MCU interface module mainly completes the issuance of drive commands and the acquisition of feedback signals, and is used to complete the data interaction between the MCU and the drive module, the feedback acquisition module and the current acquisition module; the isolation buffer module completes the isolation between the internal circuit and the drive circuit, reduces the drive current pressure of the MCU and avoids the mutual influence between the two ground systems; the drive module is used to drive the solenoid valve, converts the drive signal sent by the MCU from TTL level to a 24V or 36V level with drive ability to drive the solenoid valve; the feedback acquisition module is used to collect the drive signal, and then sends the collected feedback signal back to the MCU through the MCU interface module. The MCU can confirm whether there is a fault in the circuit by comparing the drive signal and the feedback signal; the current acquisition module is used to collect the drive current in real time, and then converts the current signal into a voltage signal and feeds it back to the MCU through the MCU interface module. The MCU can judge whether there is an overcurrent phenomenon by monitoring the drive current, so as to prevent the solenoid valve from burning out and protect the solenoid valve device.

[0036] The power supply module completes the conversion of the input power supply, converts the commonly used 24V or 48V power supply in industry into the power supply for driving the solenoid valve, and can be designed into different voltages according to different types of solenoid valves, such as 12V, 24V or 36V. At the same time, it also converts the input power supply into the power supplies of 5V and 3.3V required by the chips in the circuit, and the power supply can be turned on or off through the power control signal sent by the MCU.

[0037] The circuit of the power supply monitoring module is as Figure 2 shown, including an analog comparator U1 and three adjustment resistors. The three adjustment resistors are connected in series and are respectively connected in parallel between the four pins of the analog comparator U1. The input of the analog comparator U1 is connected to the power supply module, and the output is connected to the MCU interface module.

[0038] The analog comparator U1 is used to monitor the power supply. By adjusting the resistance values of R1, R2 and R3, the upper and lower limits of the normal operation of the power supply are set. When VCC is within the set range, the POWER_MONITOR signal output is high level. When VCC exceeds the upper limit value or the lower limit value, the POWER_MONITOR signal output is low level. The MCU can judge whether the power supply is working properly through this signal.

[0039] The MCU interface module is used for communication between the drive circuit and the MCU control. The drive circuit includes a drive module, a feedback acquisition module and a current acquisition module. The communication content mainly includes drive output signals, feedback signals, current signals, power control signals and power failure signals.

[0040] The isolation buffer module is used for signal isolation, level conversion, and signal driving. Since most of the output signals of the MCU are TTL levels of 3.3V or 5V, and the output current is only a few milliamperes to dozens of milliamperes, it becomes rather strenuous in the case of multi-channel output. Therefore, adding a stage of circuit buffer not only reduces the driving pressure on the MCU but also can uniformly convert the levels of the MCU to 5V levels by selecting different buffers; the isolation circuit isolates the internal signals connected to the MCU and the external signals connected to the driving signals, avoiding interference and damage to the internal signals and devices caused by external static electricity, high voltage, etc.

[0041] The isolation buffer module is used for signal isolation, level conversion, and signal driving. Since most of the output signals of the MCU are TTL levels of 3.3V or 5V, and the output current is only a few milliamperes to dozens of milliamperes, it becomes rather strenuous in the case of multi-channel output. Therefore, adding a stage of circuit buffer not only reduces the driving pressure on the MCU but also can uniformly convert the levels of the MCU to 5V levels by selecting different buffers; the isolation circuit isolates the internal signals connected to the MCU and the external signals connected to the driving signals, avoiding interference and damage to the internal signals and devices caused by external static electricity, high voltage, etc.

[0042] The circuit in the driving module is as Figure 3 shown. This circuit converts the isolated and buffered driving signal into a 24V or 36V driving voltage and then sends it to the driving interface. U2 is a power electronic switch chip. In the present invention, the selected chip model is BTS724. Each chip has four driving signals, and the driving capacity of each path can reach 3A. If a larger driving current is required, multiple paths can be used in parallel. Using a power electronic switch, the circuit design is simple, without the need for complex resistor-capacitor circuits and MOS circuits. Compared with the traditional bridge driving circuit, the volume is only one-third of the original. And because the on-resistance of the power electronic switch is extremely small and the power consumption is very small, no additional heat dissipation device is required either.

[0043] The circuit in the feedback acquisition module is as Figure 4 shown. This circuit uses a comparator to collect the driving signal. When the driving signal is at a high level, the sampling voltage is higher than the reference voltage, and the comparator outputs a high level. When the driving signal is at a low level, the sampling voltage is lower than the reference voltage, and the comparator outputs a low level. The collected signal is transmitted to the MCU after passing through the isolation buffer circuit. The MCU judges whether the driving output is true and effective by comparing the driving instruction and the collected signal. If the comparison result is inconsistent, the MCU can turn off the power supply in the driving circuit through the power control instruction and stop the driving output, thus achieving the effect of protecting the solenoid valve.

[0044] The circuit in the current acquisition module is as Figure 5As shown, the current acquisition module includes a current sampling and conversion circuit, a conditioning circuit, a follower circuit, an isolation amplifier, and a detection circuit connected in sequence. The current sampling and conversion circuit includes a sampling resistor and a capacitor connected in parallel. Both the conditioning circuit and the follower circuit use amplifiers. The detection circuit includes two amplifiers connected in series, and a diode is connected in series between the two amplifiers. The model of the isolation amplifier is AMC1200.

[0045] The signal acquisition of current is generally completed by a sampling resistor or a Hall element. In the circuit of the present invention, a high-precision sampling resistor is used to convert the current signal into a voltage signal. The obtained signal is a PWM wave signal with the same frequency and duty cycle as the driving signal. Then, the internal and external circuit systems are isolated through the isolation amplifier. The detection circuit is used to convert the collected PWM wave into a DC voltage, and then it is transmitted to the ADC through the MCU interface. The current flowing through the sampling resistor and the voltage collected by the ADC are linearly related. The MCU can judge whether the solenoid valve is overcurrent by calculating the driving current, thus forming a warning or protection mechanism.

[0046] The working method of the solenoid valve driving circuit device of the present invention includes the following processes:

[0047] The power supply module supplies power to the other components in the circuit. The MCU sends a driving signal to the driving module through the MCU interface module. The driving module drives the solenoid valve to work. The feedback acquisition module acquires the driving signal, and then transmits the acquired feedback signal back to the MCU through the MCU interface module. The MCU confirms whether there is a fault in the circuit by comparing the driving signal and the feedback signal; the current acquisition module continuously acquires the driving current, and then converts the current signal into a voltage signal and feeds it back to the MCU through the MCU interface module. The MCU judges whether there is an overcurrent phenomenon by monitoring the driving current. If there is a fault or an overcurrent phenomenon in the circuit, the MCU sends a stop signal to the driving module through the MCU interface module.

[0048] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprises", "comprising" or any other variation thereof is intended to cover a non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not expressly listed, or elements inherent to such process, method, article or device.

[0049] It should be understood that the above description is for illustrative purposes and not for limitation. Upon reading the above description, many embodiments and many applications beyond the provided examples will be apparent to those skilled in the art. Therefore, the scope of the present teachings should not be determined with reference to the above description, but rather should be determined with reference to the full scope of the foregoing claims and the equivalents thereof. For the sake of completeness, all articles and references, including the disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein from the foregoing claims is not intended to abandon such subject matter, nor should it be considered that the applicant has not considered such subject matter to be a part of the disclosed inventive subject matter.

Claims

1. A solenoid valve drive circuit device, characterized in that, it includes a power supply module, an MCU interface module, a drive module, a feedback acquisition module, and a current acquisition module; The power supply module is connected to all other devices. The output end of the MCU interface module is connected to the input end of the drive module. The input ends of the feedback acquisition module and the current acquisition module are both connected to the output end of the drive module. The output ends of the feedback acquisition module and the current acquisition module are both connected to the input end of the MCU interface module; the MCU interface module is connected to an MCU; The power supply module is used for supplying power to the devices in the circuit and providing drive current for the drive interface; The drive module is used to drive the solenoid valve, converting the drive signal sent by the MCU from TTL level to a level with driving ability to drive the solenoid valve; The feedback acquisition module is used to collect the drive signal, and then send the collected feedback signal back to the MCU through the MCU interface module. The MCU can confirm whether there is a fault in the circuit by comparing the drive signal and the feedback signal; The current acquisition module is used to collect the drive current in real time, converting the current signal into a voltage signal and feeding it back to the MCU through the MCU interface module; The MCU interface module mainly completes the issuance of drive commands and the acquisition of feedback signals, and is used to complete the data interaction between the MCU and the drive circuit; the MCU is used to compare the drive signal and the feedback signal to confirm whether there is a fault in the circuit, and monitor the drive current to determine whether there is an overcurrent phenomenon; The current acquisition module includes a current sampling conversion circuit, a conditioning circuit, a follower circuit, an isolation amplifier, and a detection circuit connected in sequence; A power supply monitoring module is arranged between the power supply module and the MCU interface module. The power supply monitoring module is used to monitor the voltage of the power supply in the circuit for power supply fault alarm.

2. The solenoid valve drive circuit device according to claim 1, characterized in that, The drive circuit uses a power electronic switch chip.

3. The solenoid valve drive circuit device according to claim 1, characterized in that, The feedback acquisition module includes a comparator U3. The two input ends of the comparator U3 are respectively connected to the output end of the drive module and the output end of the power supply module. The output end of the comparator U3 is connected to the input end of the MCU interface module.

4. The solenoid valve drive circuit device according to claim 1, characterized in that, The current sampling conversion circuit includes a sampling resistor and a capacitor connected in parallel.

5. The solenoid valve drive circuit device according to claim 1, characterized in that, Both the conditioning circuit and the follower circuit use amplifiers.

6. The solenoid valve drive circuit device according to claim 1, characterized in that, The detection circuit includes two amplifiers connected in series, and a diode is connected in series between the two amplifiers.

7. The solenoid valve drive circuit device according to claim 1, characterized in that, An isolation buffer module is arranged between the MCU interface module and the drive module, the feedback acquisition module, and the current acquisition module.

8. A working method of the solenoid valve drive circuit device according to any one of claims 1-7, characterized in that, The power supply module supplies power to the remaining devices in the circuit. The MCU sends a driving signal to the driving module through the MCU interface module. The driving module drives the solenoid valve to work. The feedback acquisition module acquires the driving signal and then sends the acquired feedback signal back to the MCU through the MCU interface module. The MCU confirms whether there is a fault in the circuit by comparing the driving signal and the feedback signal. The current acquisition module continuously acquires the driving current and then converts the current signal into a voltage signal and feeds it back to the MCU through the MCU interface module. The MCU determines whether there is an overcurrent phenomenon by monitoring the driving current. If there is a fault or an overcurrent phenomenon in the circuit, the MCU sends a stop signal to the driving module through the MCU interface module.

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