Integrated vacuum generator control circuit

Abstract

The invention relates to the technical field of control circuits, in particular to an integrated vacuum generator control circuit which comprises an ADC voltage detection circuit and a voltage follower circuit constructed by an operational amplifier so as to realize external detection of a pressure sensor. The main control unit is used for controlling the opening and closing of the electromagnetic valve driving module and the level output module according to a configured threshold parameter through a pressure analog voltage value output by the ADC voltage detection circuit; and the communication unit is used for realizing communication between the main control unit and an upper computer and carrying out parameter configuration on the main control unit through a modbus communication protocol. The circuit is simplified through integrated design, the cost is reduced, and the integration level is improved. The voltage follower circuit accurately detects signals of the pressure sensor, and control precision is improved. RS485 and modbus protocols are adopted, so that the communication stability and flexibility are enhanced, and the system is suitable for various application scenes. The method has remarkable technical advantages and application prospects.

Description

Technical Field

[0001] The invention relates to the technical field of control circuits, and in particular to an integrated vacuum generator control circuit. Background Art

[0002] The vacuum generator is an innovative, efficient, clean, economical, and miniaturized vacuum component that generates negative pressure by using a positive pressure gas source. The emergence of this device makes it very easy and convenient to obtain negative pressure in any place where compressed air is available, or in situations where positive and negative pressures are required in a pneumatic system. Due to its unique advantages, vacuum generators have been widely used in the field of industrial automation, including but not limited to machinery, electronics, packaging, printing, plastics, and robotics.

[0003] However, there are some problems with the vacuum generator control circuits currently on the market. The structures of these circuits are usually complex, which not only leads to an increase in cost, but also makes integration difficult. In addition, the control accuracy is insufficient, making it difficult to accurately control the vacuum degree. The single communication method also limits its flexibility and applicability in different application scenarios. In view of the problems existing in the above-mentioned prior art, the present invention proposes an integrated vacuum generator control circuit. The design goal of this control circuit is to solve the key problems of the prior art, such as the complex structure of the control circuit, the low control accuracy and the single communication method, so as to provide a more efficient, accurate and adaptable vacuum generator control solution. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention discloses an integrated vacuum generator control circuit for solving the above problems.

[0005] The present invention is achieved through the following technical solutions:

[0006] The present invention provides an integrated vacuum generator control circuit, comprising:

[0007] ADC voltage detection circuit, using operational amplifier to build voltage follower circuit to realize external detection of pressure sensor;

[0008] The main control unit controls the opening and closing of the solenoid valve drive module and the level output module according to the configured threshold parameters through the pressure analog voltage value output by the ADC voltage detection circuit;

[0009] The communication unit is used to realize the communication between the main control unit and the host computer, and configure the parameters of the main control unit through the modbus communication protocol.

[0010] Furthermore, the main control unit converts serial data into parallel data through a shift register, and outputs the data to the bases of the NPN-type driving transistor supply solenoid valve and the destruction solenoid valve, respectively, so as to realize the opening and closing control of the supply valve and the destruction valve.

[0011] Furthermore, the NPN type driving transistor supplies the coil of the electromagnetic valve and destroys the electromagnetic valve as a collector load connected between the collector and the positive power supply.

[0012] Furthermore, in the NPN type driving transistor supplying the solenoid valve and the destruction solenoid valve, when the base input is 0V, the transistor is cut off, no current flows through the solenoid valve coil, and the solenoid valve is released; on the contrary, when the base input is the threshold voltage, the transistor is turned on, current flows through the solenoid valve coil, and the solenoid valve is closed.

[0013] Furthermore, the communication unit is an RS485 communication circuit, which uses differential signals for data transmission, so as to improve the anti-interference ability and transmission distance of data transmission, and ensure stable and reliable communication between the main control unit and the host computer.

[0014] Furthermore, the modbus communication protocol uses RTU mode for data communication, and adopts binary encoding and CRC check to ensure the accuracy and integrity of data transmission.

[0015] Furthermore, the integrated vacuum generator control circuit also includes a fault detection module for monitoring the working status of the solenoid valve drive module and the level output module in real time. Once an abnormality is found, a fault signal is immediately sent to the main control unit, and the main control unit responds according to a preset fault handling strategy.

[0016] Furthermore, the pressure sensor is powered by a constant current or constant voltage.

[0017] The beneficial effects of the present invention are:

[0018] The present invention simplifies the circuit structure, reduces the cost and improves the integration through a highly integrated design. The voltage follower circuit constructed by using the ADC voltage detection circuit and the operational amplifier can accurately detect the external signal of the pressure sensor and improve the control accuracy. The precise control of the solenoid valve drive module and the level output module by the main control unit realizes the precise regulation of the vacuum generator. In addition, the RS485 communication circuit and the modbus communication protocol are adopted to enhance the stability and flexibility of the communication, so that the control circuit can adapt to different application scenarios. The addition of the fault detection module further improves the reliability and safety of the system. In summary, the present invention provides a more efficient, accurate and adaptable vacuum generator control solution with significant technical advantages and application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 It is the schematic diagram of the integrated vacuum generator control circuit;

[0021] Figure 2 This is the circuit diagram of the triode driven solenoid valve;

[0022] Figure 3 It is a constant current power supply circuit diagram;

[0023] Figure 4 This is the pressure sensor output amplifier circuit diagram. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] In one embodiment, referring to Figure 1 As shown, the present invention relates to an innovative technology, which proposes a design scheme for an integrated vacuum generator control circuit. The control circuit is mainly composed of several key parts, including a main control chip, an RS485 communication circuit, a pressure sensor output amplifier circuit, an electromagnetic valve drive circuit, an ADC voltage detection circuit, and a high and low level output circuit. The main control chip (MCU) plays a core role, which exchanges data and transmits information with the host computer through the RS485 communication circuit. In this process, the main control chip uses the modbus communication protocol to configure the parameters of the integrated main control to ensure the normal operation and precise control of the entire system.

[0026] In addition, the main control chip is also responsible for monitoring the pressure analog voltage value output by the external pressure sensor through the ADC (analog to digital converter) voltage detection circuit. This process is achieved through the voltage follower circuit composed of operational amplifiers, which can accurately detect the signal of the pressure sensor. According to the pre-set threshold parameters, the main control chip will accurately open and close the solenoid valve drive module and the level output module, thereby achieving efficient management of the vacuum generator.

[0027] In this embodiment, the design of the ADC voltage detection circuit uses an operational amplifier to construct a voltage follower circuit, which can effectively improve the circuit's detection accuracy and response speed to external pressure sensor signals. The high and low level output circuit uses an NPN Darlington tube to enhance its output drive capability, ensuring that it can provide sufficient current to drive loads such as solenoid valves when needed, thereby ensuring the stability and reliability of the system.

[0028] In one embodiment, a solenoid valve driving circuit is provided, wherein the MCU converts serial data into parallel data through a shift register (U9, U11) and outputs the data to the bases of the supply valve and the destruction valve driving transistors respectively, thereby controlling the opening and closing thereof.

[0029] In this implementation, if Figure 2 The circuit diagram example of using an NPN transistor to drive a solenoid valve is shown in the figure. In this circuit, the coil of the solenoid valve is used as the load of the collector, and it is connected between the collector and the positive power supply. When the base receives a 0 volt input signal, the transistor will enter the cut-off state, and no current will flow through the solenoid valve coil, so the solenoid valve will be in a released state; in contrast, when the base receives a +3.3 volt input signal, the transistor will be turned on, and current will flow through the solenoid valve coil, causing the solenoid valve to be attracted.

[0030] In this embodiment, LED1 is connected in parallel with the solenoid valve, and such a design enables LED1 to be used as an indicator light for indicating the on and off status of the solenoid valve. In addition, resistor R103 is set as a pull-down resistor, which prevents the transistor from accidentally turning on when there is no input signal, thereby ensuring the stability and reliability of the circuit.

[0031] In this embodiment, Figure 2 The values ​​of resistors R112 and R103 should be such that the transistor is saturated and turned on when the base input is +3.3V, that is, βIb>Ies. Assume Figure 2In the case of Vb=3.3V, Ies=60mA, β=100, Ib>0.6mA, and Ib=(Vb-Vbe) / R112-Vbe / R103. If R2=4.7K, R1<3.47K. In order to make the transistor have a certain saturation depth and take into account the discreteness of the transistor current amplification factor, R1 is generally taken as around 1K.

[0032] In the embodiment, the D27 diode is used as a freewheeling element, and its function is as follows: when the input voltage VIN drops to zero volts, the transistor changes from a saturated state to a cut-off state. At this time, the current in the solenoid valve inductor suddenly loses its flow path. If there is no freewheeling diode D27, a significant reverse electromotive force will be generated at both ends of the coil, and its polarity is positive at the lower end and negative at the upper end. This reverse electromotive force is superimposed on the power supply voltage and acts on the collector of the transistor, which may cause damage to the transistor. Therefore, the role of the freewheeling diode D27 is to release the reverse electromotive force through the discharge mechanism of the diode, ensuring that the peak voltage of the transistor collector to the ground does not exceed the input voltage VIN plus the forward conduction voltage of the diode (0.7V).

[0033] In this embodiment, a protection circuit is also used to prevent the components in the circuit from being damaged by overvoltage or overcurrent. When the power supply voltage is too high or the current in the solenoid valve coil is too large, the protection circuit will quickly cut off the power supply to prevent the components in the circuit from being damaged. This design greatly improves the reliability and safety of the circuit.

[0034] In one embodiment, the pressure sensor may be powered by a constant current and constant voltage mode, and the power supply is: ≤15V DC or ≤3.0mA DC. This embodiment uses a constant current power supply, and the supply current is 1mA.

[0035] Reference Figure 3 As shown, resistors R14 and R15 form a voltage divider circuit, and the voltage at the common-mode input of the operational amplifier The voltage at the inverting input terminal is Vn=Vp, and the voltage on the sampling resistor R12 is VR12=Vn=Vp, so the current flowing through the load is

[0036] In one embodiment, referring to Figure 4 The pressure sensor output amplifier circuit shown in the figure, the voltage follower circuit composed of resistors R3, R4 and operational amplifier U16.3 provides a bias voltage Vin for the amplifier circuit.

[0037] The circuit of the operational amplifier U16.2 is a reverse proportional amplifier circuit. According to the "virtual short" and "virtual open", the voltage at the inverting input terminal is equal to the voltage at the non-inverting input terminal, that is, Vn = Vp = OUT_. The voltage Vout1 at the output of the operational amplifier is expressed as formula (3-2).

[0038]

[0039] The circuit of the operational amplifier U16.4 is a reverse proportional amplifier circuit, Vn = Vp = OUT+, and the voltage Vout2 at the output of the operational amplifier is expressed as (3-3).

[0040]

[0041] In the circuit, the resistors R11=R6, R9=R8. Substituting equations (3-1) and (3-2) into equation (3-3), we get equation (3-4):

[0042]

[0043] Therefore, the final output voltage of the pressure sensor output amplifier circuit is formula (3-4).

[0044] In this embodiment, the communication unit adopts RS485 communication circuit, which uses differential signals to transmit data. This transmission method can significantly improve the anti-interference ability during data transmission and can effectively increase the transmission distance. In this way, we ensure that the communication between the main control unit and the host computer is stable and reliable.

[0045] In addition, the modbus communication protocol is also used in this embodiment, and the RTU mode is specifically used for data communication. In the data communication process, binary coding and CRC verification technology are adopted. The binary coding method can improve the efficiency of data processing, and the CRC verification is a powerful error detection mechanism, which can ensure the accuracy and integrity of data during transmission, thereby further ensuring the reliability of communication.

[0046] In this embodiment, the integrated vacuum generator control circuit not only includes basic control functions, but also specially designed a fault detection module. The fault detection module has the ability of real-time monitoring and can continuously track the working status of the solenoid valve drive module and the level output module. Through this continuous monitoring, the system can detect any possible abnormal situation in time. Once any abnormal working state is detected, the fault detection module will immediately send a fault signal to the main control unit. After receiving this signal, the main control unit will respond accordingly according to the pre-set fault handling strategy. This design ensures the stability and reliability of the entire system, and can take quick measures when problems occur, thereby reducing downtime and improving production efficiency.

[0047] In summary, the present invention simplifies the circuit structure, reduces the cost, and improves the integration through a highly integrated design. The voltage follower circuit constructed using the ADC voltage detection circuit and the operational amplifier can accurately detect the external signal of the pressure sensor and improve the control accuracy. Through the precise control of the solenoid valve drive module and the level output module by the main control unit, precise regulation of the vacuum generator is achieved. In addition, the use of RS485 communication circuit and modbus communication protocol enhances the stability and flexibility of communication, so that the control circuit can adapt to different application scenarios. The addition of the fault detection module further improves the reliability and safety of the system. In summary, the present invention provides a more efficient, accurate and adaptable vacuum generator control solution with significant technical advantages and application prospects.

[0048] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An integrated vacuum generator control circuit, characterized in that: include ADC voltage detection circuit, using operational amplifier to build voltage follower circuit to realize external detection of pressure sensor; The main control unit controls the opening and closing of the solenoid valve drive module and the level output module according to the configured threshold parameters through the pressure analog voltage value output by the ADC voltage detection circuit; The communication unit is used to realize the communication between the main control unit and the host computer, and configure the parameters of the main control unit through the modbus communication protocol.

2. An integrated vacuum generator control circuit according to claim 1, characterized in that: The main control unit converts serial data into parallel data through a shift register, and outputs the data to the bases of the NPN type driving transistor supply solenoid valve and the destruction solenoid valve respectively, so as to realize the opening and closing control of the supply valve and the destruction valve.

3. An integrated vacuum generator control circuit according to claim 2, characterized in that: The NPN type driving transistor supplies the solenoid valve and destroys the coil of the solenoid valve as a collector load and is connected between the collector and the positive power supply.

4. An integrated vacuum generator control circuit according to claim 3, characterized in that: In the NPN type driving transistor supplying the solenoid valve and the destroying solenoid valve, when the base input is 0V, the transistor is cut off, no current flows through the solenoid valve coil, and the solenoid valve is released; on the contrary, when the base input is the threshold voltage, the transistor is turned on, current flows through the solenoid valve coil, and the solenoid valve is attracted.

5. The integrated vacuum generator control circuit according to claim 1, characterized in that: The communication unit is an RS485 communication circuit, which uses differential signals for data transmission, and is used to improve the anti-interference ability and transmission distance of data transmission, thereby ensuring stable and reliable communication between the main control unit and the host computer.

6. The integrated vacuum generator control circuit according to claim 1, characterized in that: The modbus communication protocol uses the RTU mode for data communication and adopts binary encoding and CRC check to ensure the accuracy and integrity of data transmission.

7. The integrated vacuum generator control circuit according to claim 1, characterized in that: The integrated vacuum generator control circuit also includes a fault detection module for real-time monitoring of the working status of the solenoid valve drive module and the level output module. Once an abnormality is found, a fault signal is immediately sent to the main control unit, and the main control unit responds according to a preset fault handling strategy.

8. The integrated vacuum generator control circuit according to claim 1, characterized in that: The pressure sensor is powered by a constant current or constant voltage mode.

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