Current signal control circuit for indicating valve opening degree and control method thereof
By designing a current signal control circuit that includes a microprocessor and a relay, the problem of signal loss after power failure in the regulating valve control system is solved, and the current signal is continuously output in the event of power failure, ensuring stable system operation and easy monitoring.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- XIAN AEROSPACE YUANZHENG FLUID CONTROL
- Filing Date
- 2023-02-15
- Publication Date
- 2026-07-07
AI Technical Summary
In regulating valve control systems, when the equipment loses power, the 4-20mA current signal instantly becomes 0mA, causing the upper-level monitoring system to be unable to obtain the working status in a timely manner. Existing UPS backup power solutions are costly and difficult to maintain.
The current signal control circuit, composed of a microprocessor, digital potentiometer, voltage/current converter, supercapacitor, PWM to voltage chip, isolated DC/DC power supply module, high-speed optocoupler and relay, combined with abnormal current signal generation circuit and relay switching state, ensures that it can still output 4-20mA current signal when power is lost.
After a power outage, the system can continuously output a 4-20mA current signal for more than 24 hours, ensuring the stable operation of the valve control system, reducing costs, and facilitating timely monitoring and response to abnormal conditions by the upper-level monitoring system.
Smart Images
Figure CN116293031B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of valve control system technology, and in particular to a current signal control circuit and control method for indicating valve opening degree. Background Technology
[0002] In regulating valve control systems, communication between field devices and the upper-level monitoring system typically uses a 4-20mA current signal. The current signal generation circuit of a regulating valve control system consists of a digital-to-analog circuit and a voltage-to-current conversion circuit. When the system loses power, the current signal becomes 0mA. However, in actual industrial automation systems, when a device unexpectedly loses power, the upper-level monitoring system needs to obtain the device's operating status at the moment of power failure to take appropriate countermeasures. But usually, after a power failure, the device's output 4-20mA signal instantly becomes 0mA, the regulating valve control system cannot operate stably, and the upper-level monitoring system cannot promptly obtain the device's operating status at the moment of power failure to take timely countermeasures. Even if some work sites adopt UPS backup power solutions to deal with this situation, UPS backup power supplies are expensive. When there are many types and numbers of devices, the overall system cost will be very high, and UPS power supplies themselves have a high failure rate and high maintenance costs. Summary of the Invention
[0003] The purpose of this invention is to overcome the problems of the prior art and to provide a current signal control circuit for representing valve opening degree, as well as a control method for the current signal control circuit for representing valve opening degree.
[0004] To achieve the above objectives, the present invention adopts the following solution:
[0005] A current signal control circuit for indicating valve opening includes a microprocessor, a digital potentiometer, a first voltage-to-current converter, a second voltage-to-current converter, a supercapacitor, a PWM to voltage converter chip, an isolated DC / DC power supply module, a high-speed optocoupler, and a relay.
[0006] The microprocessor is electrically connected to a high-speed optocoupler, a digital potentiometer, and a relay, respectively.
[0007] A high-speed optocoupler, a PWM to voltage converter chip, a first voltage / current converter, and an isolated DC / DC power supply module form a normal current signal generation circuit.
[0008] The high-speed optocoupler, PWM to voltage converter chip, and first voltage / current converter are electrically connected in sequence; the isolated DC / DC power supply module is electrically connected to the high-speed optocoupler, PWM to voltage converter chip, and first voltage / current converter respectively.
[0009] The digital potentiometer, the second voltage / current converter, and the supercapacitor form an abnormal current signal generation circuit.
[0010] The microprocessor, digital potentiometer, and second voltage / current converter are electrically connected in sequence.
[0011] The supercapacitor is electrically connected to the digital potentiometer;
[0012] The relays are electrically connected to the first voltage / current converter and the second voltage / current converter, respectively.
[0013] Furthermore, the relay includes a normally open contact and a normally closed contact; the first voltage / current converter and the second voltage / current converter are electrically connected to the normally open contact and the normally closed contact, respectively.
[0014] Furthermore, the high-speed optocoupler is a high-speed optocoupler of model HCPL-0600-500E.
[0015] Furthermore, the PWM to voltage converter chip is model GP8500.
[0016] Furthermore, the isolated DC / DC power module is a DC / DC power module of model B0505ST16-W5.
[0017] Furthermore, both the first voltage / current converter and the second voltage / current converter are XTR115U model voltage / current converters.
[0018] This invention also provides a control method for a current signal control circuit representing valve opening, implemented using the current signal control circuit for representing valve opening as described above. The relay has two switching states: energized and de-energized. The specific steps are as follows:
[0019] S1. System power-on;
[0020] S2, The microprocessor controls the relay to be in the energized state;
[0021] S3. The normal current signal generation circuit and the normal current signal generation circuit operate simultaneously, and the first voltage / current converter and the second voltage / current converter generate the first current signal and the second current signal respectively; wherein, the first current signal and the second current signal are both 4-20mA current signals;
[0022] S4. The microprocessor receives the switching status of the relay to determine whether the system has lost power.
[0023] S41. If so, a fault maintenance alarm signal is issued, the relay is in the open state, and a second current signal is output.
[0024] S42. If not, the relay is in the energized state and outputs the first current signal.
[0025] Compared with existing technologies, the present invention has the following advantages:
[0026] This invention combines a microprocessor, a normal current signal generation circuit, an abnormal current signal generation circuit, and a relay. In the abnormal current signal generation circuit, a supercapacitor continuously supplies power to a digital potentiometer. The digital potentiometer, acting as a digital-to-analog converter, maintains continuous output even without power loss. When the system is powered on and operating normally, both the normal and abnormal current signal generation circuits operate simultaneously. A first voltage / current converter and a second voltage / current converter generate a first current signal and a second current signal, both 4-20mA. The relay is in the energized state, and the first voltage / current converter is connected to the relay, outputting only the first current signal. When the system is powered off, the relay is in the de-energized state, and the second voltage / current converter is connected to the relay. The abnormal current signal generation circuit operates normally, and the supercapacitor continuously supplies power to the digital potentiometer, outputting the second current signal. This allows for continuous output of a 4-20mA current signal for over 24 hours, ensuring the valve control system continues to operate stably and normally. It is low-cost and facilitates timely monitoring by a supervisory control system, enabling rapid responses to abnormal states in the current signal control circuit indicating valve opening. Attached Figure Description
[0027] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.
[0028] Figure 1 This is a flowchart of the electrical control process of the current signal control circuit for representing valve opening degree according to the present invention.
[0029] Figure 2 This is a circuit diagram of the current signal control circuit for indicating valve opening degree according to the present invention.
[0030] Figure 3 This is a flowchart of the control method of the current signal control circuit representing the valve opening degree according to the present invention.
[0031] The image includes:
[0032] 1. Microprocessor; 2. Digital potentiometer; 3. First voltage / current converter; 4. Second voltage / current converter; 5. Supercapacitor; 6. PWM to voltage converter chip; 7. Isolated DC / DC power supply module; 8. High-speed optocoupler; 9. Relay. Detailed Implementation
[0033] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.
[0034] like Figures 1 to 3 As shown, a current signal control circuit for indicating valve opening is applied in a valve control system. This current signal control circuit for indicating valve opening includes a microprocessor 1, a digital potentiometer 2, a first voltage-to-current converter 3, a second voltage-to-current converter 4, a supercapacitor 5, a PWM-to-voltage chip 6, an isolated DC / DC power supply module 7, a high-speed optocoupler 8, and a relay 9. The microprocessor 1 is electrically connected to the high-speed optocoupler 8, the digital potentiometer 2, and the relay 9. The high-speed optocoupler 8, the PWM-to-voltage chip 6, the first voltage-to-current converter 3, and the isolated DC / DC power supply module 7 form a normal current signal generation circuit. The high-speed optocoupler 8, the PWM-to-voltage chip 6, and the first voltage-to-current converter 3 are electrically connected sequentially; the isolated DC / DC power supply module 7 is electrically connected to the high-speed optocoupler 8, the PWM-to-voltage chip 6, and the first voltage-to-current converter 3. In this system, the microprocessor 1 serves as the host monitoring system. The high-speed optocoupler 8 is a model HCPL-0600-500E, which transmits electrical signals using light as a medium. It provides excellent isolation between input and output electrical signals and features advantages such as small size, long lifespan, no contacts, strong anti-interference capability, insulation between output and input, and unidirectional signal transmission. The PWM to voltage converter chip 6 is a model GP8500. The isolated DC / DC power module 7 is a model B0505ST16-W5 DC / DC power module used as a power supply. The digital potentiometer 2, the second voltage / current converter 4, and the supercapacitor 5 form an abnormal current signal generation circuit. The supercapacitor 5 is a power supply with special properties that provides power to the digital potentiometer 2. The microprocessor 1, digital potentiometer 2, and second voltage / current converter 4 are electrically connected in sequence. The supercapacitor 5 is electrically connected to the digital potentiometer 2. The relay 9 is electrically connected to the first voltage / current converter 3 and the second voltage / current converter 4, respectively. The first voltage / current converter 3 and the second voltage / current converter 4 are both XTR115U model voltage / current converters.
[0035] The current signal control circuit indicating valve opening combines a microprocessor 1, a normal current signal generation circuit, an abnormal current signal generation circuit, and a relay 9. In the abnormal current signal generation circuit, a supercapacitor 5 continuously supplies power to a digital potentiometer 2. The digital potentiometer 2, acting as a digital-to-analog converter, maintains continuous output even without power loss. When the system is powered on and operating normally, the normal current signal generation circuit and the abnormal current signal generation circuit operate simultaneously. The first voltage / current converter 3 and the second voltage / current converter 4 generate a first current signal and a second current signal, respectively. Both the first and second current signals are 4-20mA current signals. The relay... Relay 9 is currently in the energized state, and the first voltage / current converter 3 is connected to relay 9, outputting only the first current signal. When the system loses power, relay 9 is in the de-energized state, and the second voltage / current converter 4 is connected to relay 9. The abnormal current signal generation circuit operates normally, and the supercapacitor 5 continuously supplies power to the digital potentiometer 2, outputting the second current signal. It can continuously output a 4-20mA current signal for more than 24 hours, ensuring the valve control system continues to operate stably and normally. It is low in cost and facilitates timely monitoring by the upper-level monitoring system, enabling rapid response to abnormal states of the current signal control circuit indicating valve opening.
[0036] Specifically, the relay 9 includes normally open and normally closed contacts; the first voltage / current converter 3 and the second voltage / current converter 4 are electrically connected to the normally open and normally closed contacts, respectively. The relay 9 has advantages such as fast operation, stable operation, long service life, and small size. When the system is powered on and operating normally, the switch of the relay 9 connects to the normally open contact, and the first voltage / current converter 3 is connected to the relay 9. When the system experiences a power outage, the switch of the relay 9 connects to the normally closed contact, and the second voltage / current converter 4 is connected to the relay 9. During a power outage, it can continuously output a 4-20mA current signal for more than 24 hours, ensuring the valve control system continues to operate stably and normally, facilitating timely monitoring by the upper-level monitoring system.
[0037] This invention also provides a control method for a current signal control circuit representing valve opening, implemented using the current signal control circuit for representing valve opening as described above. The relay 9 has two switching states: energized and de-energized. The specific steps are as follows:
[0038] S1. System power-on;
[0039] S2, Microprocessor 1 controls relay 9 to be in the energized state;
[0040] S3. The normal current signal generation circuit and the normal current signal generation circuit operate simultaneously, and the first voltage / current converter 3 and the second voltage / current converter 4 generate the first current signal and the second current signal respectively; wherein, the first current signal and the second current signal are both 4-20mA current signals;
[0041] S4. Microprocessor 1 receives the switching status of relay 9 and determines whether the system has lost power;
[0042] S41. If so, a fault maintenance alarm signal is issued, relay 9 is in the open state, and a second current signal is output;
[0043] S42. If not, relay 9 is in the energized state and outputs the first current signal.
[0044] In summary, this control method, which uses a current signal control circuit to represent the valve opening degree, can continuously output a 4-20mA current signal for more than 24 hours when the system loses power, ensuring the valve control system continues to operate stably and normally. It is low in cost and facilitates timely monitoring by the upper-level monitoring system, enabling rapid response to abnormal states of the current signal control circuit representing the valve opening degree.
[0045] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of this application, and these improvements and substitutions should also be considered within the scope of protection of this application.
Claims
1. A current signal control circuit for indicating valve opening degree, characterized in that, Including microprocessors, digital potentiometers, First voltage / current converter, second voltage / current converter, supercapacitor, PWM to voltage converter chip, isolated DC / DC power supply module, high-speed optocoupler and relay; The microprocessor is electrically connected to a high-speed optocoupler, a digital potentiometer, and a relay, respectively. A high-speed optocoupler, a PWM to voltage converter chip, a first voltage / current converter, and an isolated DC / DC power supply module form a normal current signal generation circuit. The high-speed optocoupler, PWM to voltage converter chip, and first voltage / current converter are electrically connected in sequence; the isolated DC / DC power supply module is electrically connected to the high-speed optocoupler, PWM to voltage converter chip, and first voltage / current converter respectively. The digital potentiometer, the second voltage / current converter, and the supercapacitor form an abnormal current signal generation circuit. The microprocessor, digital potentiometer, and second voltage / current converter are electrically connected in sequence. The supercapacitor is electrically connected to the digital potentiometer; The relays are electrically connected to the first voltage / current converter and the second voltage / current converter, respectively. The relay includes normally open contacts and normally closed contacts; the first voltage / current converter and the second voltage / current converter are electrically connected to the normally open contacts and the normally closed contacts, respectively. The high-speed optocoupler is a high-speed optocoupler of model HCPL-0600-500E; The PWM to voltage converter chip is model GP8500; The isolated DC / DC power module is model B0505ST16-W5.
2. The current signal control circuit for indicating valve opening degree according to claim 1, characterized in that, Both the first voltage / current converter and the second voltage / current converter are XTR115U model voltage / current converters.
3. A control method for a current signal control circuit representing valve opening, characterized in that, This is achieved using a current signal control circuit representing the valve opening degree as described in any one of claims 1 to 2. The relay has two switching states: energized and de-energized. The specific steps are as follows: S1. System power-on; S2, The microprocessor controls the relay to be in the energized state; S3. The normal current signal generation circuit and the normal current signal generation circuit operate simultaneously, and the first voltage / current converter and the second voltage / current converter generate the first current signal and the second current signal respectively; wherein, the first current signal and the second current signal are both 4-20mA current signals; S4. The microprocessor receives the switching status of the relay to determine whether the system has lost power. S41. If so, a fault maintenance alarm signal is issued, the relay is in the open state, and a second current signal is output. S42. If not, the relay is in the energized state and outputs the first current signal.