FAS cylinder solenoid valve driving signal load capacity testing device

Abstract

The utility model discloses a kind of FAS cylinder solenoid valve driving signal load capacity testing device, including MCU main control circuit, electronic load constant current circuit, current detection circuit and output closing circuit;The input end of the electronic load constant current circuit is used to connect the measured solenoid valve driving signal, and its output end is grounded;The current detection circuit is connected in series in the input loop of the electronic load constant current circuit, for gathering the current value flowing through the electronic load constant current circuit, and the signal collected is transmitted to the MCU main control circuit;The output end of the MCU main control circuit is connected with the control end of the electronic load constant current circuit, for outputting constant current setting signal to the electronic load constant current circuit.The utility model passes through numerical control electronic load constant current circuit, can set the load matched with solenoid valve coil operating current, directly test the output performance of measured power supply under real load, fundamentally eliminates the security risk caused by insufficient load capacity of power supply.

Description

Technical Field

[0001] This utility model belongs to the field of rail transit facility maintenance technology, and in particular relates to a test device for the load-carrying capacity of the drive signal of the FAS gas cylinder solenoid valve. Background Technology

[0002] During the annual inspection of FAS (Fire Protection System) professional gas extinguishing systems in rail transit, the proper functioning of the gas cylinder solenoid valve is crucial for the system's effective fire suppression. The solenoid valve is typically driven by 24V DC voltage, with a power output of up to 36W. FAS gas extinguishing systems contain cylinders filled with inert gas. In the event of a fire, the solenoid valve opens, releasing the gas from the cylinder for use in rooms requiring gas extinguishing. If the FAS extinguishing panel itself malfunctions, resulting in insufficient output capacity to drive the solenoid valve, it will cause malfunctions such as the inability to open the gas cylinder, preventing gas extinguishing and potentially leading to serious consequences.

[0003] In the annual inspection of FAS professional gas extinguishing systems, maintenance personnel generally use digital multimeters to measure the open-circuit voltage of the solenoid valve plug to determine whether the emergency start function is normal. However, multimeters measure open-circuit voltage and cannot simulate the actual working state of the solenoid valve coil (load). The power module of the FAS gas extinguishing panel may have reduced load-carrying capacity due to aging or failure, resulting in a fatal problem where the open-circuit voltage is normal but the solenoid valve cannot be driven, posing a huge safety hazard. In addition, when using multimeter probes to directly contact the metal contacts of the solenoid valve plug, poor contact is very likely to lead to inaccurate or difficult-to-measure results, resulting in a poor user experience and low efficiency. Moreover, using a multimeter can only provide voltage readings, making it difficult to perform quantitative load testing, data recording, and judgment, which fails to meet the current requirements for precise and efficient equipment maintenance. Utility Model Content

[0004] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a test device for the load-carrying capacity of the solenoid valve drive signal of FAS gas cylinder, so as to solve the technical problems mentioned in the background art.

[0005] This utility model provides the following technical solution: A test device for testing the load-carrying capacity of the drive signal of the FAS gas cylinder solenoid valve includes an MCU main control circuit, an electronic load constant current circuit, a current detection circuit, and an output shutdown circuit. The input terminal of the electronic load constant current circuit is used to connect to the drive signal of the solenoid valve under test, and its output terminal is grounded. The current detection circuit is connected in series in the input circuit of the electronic load constant current circuit to collect the current value flowing through the electronic load constant current circuit and transmit the collected signal to the MCU main control circuit. The output terminal of the MCU main control circuit is connected to the control terminal of the electronic load constant current circuit, and is used to output a constant current setting signal to the electronic load constant current circuit; The control terminal of the output shutdown circuit is connected to the MCU main control circuit, and its output terminal is connected to the control terminal of the electronic load constant current circuit. It is used to receive instructions from the MCU main control circuit and can clear the constant current value of the electronic load constant current circuit to zero.

[0006] Preferably, the electronic load constant current circuit includes an operational amplifier, an NMOS transistor, and a current sampling resistor; the non-inverting input of the operational amplifier receives a constant current setting signal from the MCU main control circuit, its inverting input is connected to the source of the NMOS transistor, and its output is connected to the gate of the NMOS transistor; the drain of the NMOS transistor serves as the input of the electronic load constant current circuit, and the current sampling resistor is connected between the source of the NMOS transistor and ground.

[0007] Preferably, the output shutdown circuit includes an NMOS transistor whose gate receives a shutdown command from the MCU main control circuit, whose drain is connected to the inverting input of the operational amplifier in the electronic load constant current circuit, and whose source is grounded.

[0008] Preferably, the electronic load constant current circuit further includes an NTC thermistor, which is disposed in the power device area of ​​the electronic load constant current circuit and connected to the MCU main control circuit for acquiring temperature signals.

[0009] Preferably, it also includes a human-machine interface, which is connected to the MCU main control circuit and is used to set the constant current value and display the measured current data.

[0010] Preferably, it also includes a lithium battery, a battery switching circuit, and a boost circuit; the battery switching circuit is used to control the power supply of the lithium battery to the entire device; the boost circuit is connected to the output terminal of the battery switching circuit and is used to convert the lithium battery voltage into a stable system operating voltage.

[0011] Compared with the prior art, the present invention has the following beneficial effects: This utility model discloses a test device for the load-carrying capacity of the solenoid valve drive signal of FAS gas cylinder. Through a CNC electronic load constant current circuit, it is possible to set a load that matches the working current of the solenoid valve coil, directly verifying the output performance of the tested power supply under real load, and fundamentally eliminating the safety hazards caused by insufficient power supply load-carrying capacity. Attached Figure Description

[0012] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0013] Figure 1 This is the overall circuit block diagram of this utility model.

[0014] Figure 2 This is the circuit diagram for the input voltage detection of this utility model.

[0015] Figure 3 This is the battery power-on / off circuit diagram of this utility model.

[0016] Figure 4 This is the boost circuit diagram of this utility model.

[0017] Figure 5 This is a circuit diagram of the TP4056 lithium battery charging circuit of this utility model.

[0018] Figure 6 This is the circuit diagram of the electronic load constant current circuit of this utility model.

[0019] Figure 7 This is the circuit diagram of the LCD screen of this utility model.

[0020] Figure 8 This is the circuit diagram of the USB interface of this utility model.

[0021] Figure 9 This is the main control circuit diagram of this utility model. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0023] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0024] This utility model provides a device for testing the load-carrying capacity of the drive signal of an FAS gas cylinder solenoid valve, for reference. Figure 1-9 As shown, it includes an MCU main control circuit, an electronic load constant current circuit, a current detection circuit, and an output shutdown circuit; The input terminal of the electronic load constant current circuit is used to connect to the drive signal of the solenoid valve under test, and its output terminal is grounded. The current detection circuit is connected in series in the input circuit of the electronic load constant current circuit to collect the current value flowing through the electronic load constant current circuit and transmit the collected signal to the MCU main control circuit. The output terminal of the MCU main control circuit is connected to the control terminal of the electronic load constant current circuit, and is used to output a constant current setting signal to the electronic load constant current circuit; The control terminal of the output shutdown circuit is connected to the MCU main control circuit, and its output terminal is connected to the control terminal of the electronic load constant current circuit. It is used to receive instructions from the MCU main control circuit and can clear the constant current value of the electronic load constant current circuit to zero.

[0025] refer to Figure 1 This is the overall circuit block diagram. After the input voltage detection circuit, one path goes through a rectifier circuit and a current detection circuit before connecting to the electronic load constant current circuit. The other path goes through a polarity conversion circuit and a voltage follower signal processing circuit, then is sent to the input voltage acquisition circuit's ADC for conversion before being fed to the MCU main control circuit. The current detection circuit converts the current signal into an analog voltage, which is then converted by the ADC and sent to the MCU main control circuit. The constant current value of the electronic load constant current circuit is controlled and set by the MCU main control circuit. The MCU control output shutdown circuit can reset the constant current value of the electronic load constant current circuit to zero. An NTC resistor is included in the electronic load constant current circuit for temperature acquisition to prevent damage caused by excessively high operating temperatures. Connected to the MCU main control circuit are a USB interface circuit and an LCD screen for charging and human-machine interaction.

[0026] By using a CNC electronic load constant current circuit, a load that matches the operating current of the solenoid valve coil can be precisely set (for example, a constant current load of 1.5A can be set for a 24V / 36W coil), directly verifying the output performance of the power supply under actual load, and fundamentally eliminating safety hazards caused by insufficient power supply load capacity.

[0027] The electronic load constant current circuit includes an operational amplifier, an NMOS transistor, and a current sampling resistor. The non-inverting input of the operational amplifier receives a constant current setting signal from the MCU main control circuit, its inverting input is connected to the source of the NMOS transistor, and its output is connected to the gate of the NMOS transistor. The drain of the NMOS transistor serves as the input of the electronic load constant current circuit, and the current sampling resistor is connected between the source of the NMOS transistor and ground.

[0028] The output shutdown circuit includes an NMOS transistor whose gate receives a shutdown command from the MCU main control circuit, whose drain is connected to the inverting input of the operational amplifier in the electronic load constant current circuit, and whose source is grounded. The output shutdown circuit ensures the safety and reliability of the device's operation.

[0029] The electronic load constant current circuit also includes an NTC thermistor, which is located in the power device area of ​​the electronic load constant current circuit and connected to the MCU main control circuit for acquiring temperature signals. The NTC temperature protection circuit ensures the safety and reliability of the device itself.

[0030] It also includes a human-machine interface, which is connected to the MCU main control circuit and used to set the constant current value and display the measured current data. The human-machine interface makes the testing process intuitive and simple, eliminating the need for testers to monitor multimeter readings and greatly improving the efficiency and quality of annual inspection work.

[0031] It also includes a lithium battery, a battery switching circuit, and a boost circuit; the battery switching circuit controls the power supply of the lithium battery to the entire device; the boost circuit is connected to the output of the battery switching circuit and converts the lithium battery voltage into a stable system operating voltage. The built-in lithium battery power supply provides electrical isolation from the system under test, improving operational safety.

[0032] refer to Figure 2 This is the input voltage detection circuit. U10 is the external input interface. VIN1 and VIN2 are connected to the external input voltage. After rectification by diodes D1, D2, D3, and D4, and filtering by C14, the voltage passes through the high-side current sampling circuit. U2 INA193 performs high-side current sampling, and the current is detected by the conversion by ADS1110. R5, R9, R11, R15, R21, and R22 constitute a positive and negative 36V voltage acquisition circuit. The input voltage is switched and identified by the analog switch BL1551, thereby realizing the acquisition of the external voltage. After passing through the voltage follower circuit composed of the operational amplifier U16 LM321, the voltage is acquired by U4 ADS1110, and the external voltage data is obtained after processing and conversion by the MCU.

[0033] refer to Figure 3 This is the battery power-on / off circuit. The battery power-on / off circuit is used for power-on / off control, using a mechanical button to control the device's power on / off. It uses the MPS003 power-on / off chip, which is packaged in an SOT23-6 package. The MPS003 is small in size, reducing PCB footprint and BOM cost, and has a minimum static power consumption of 0.16uA. VDD is connected to the positive terminal of the lithium battery, and the supply voltage range is 1.8-5.5V, meeting the 2.5-4.2V voltage range of a single lithium battery. The KEY pin is connected to the button; LONG is high or floating for a long press mode, and grounded for a short press mode; OUTL is low by default after power-on, and ETH is high by default. When the KEY button is pressed, OUTL changes from low to high, and ETH changes from high to low. Q2 is a PMOS transistor AO3401A used to control the device's power on / off, and capacitor C6 is used for filtering. R26 and D7 serve as power indicator lights.

[0034] refer to Figure 4 This is a boost circuit. VCC is the output voltage of the battery power-on / off circuit. When the battery power-on / off circuit is turned on, VCC is the voltage of a single lithium battery cell, ranging from 2.5V to 4.2V. After processing by the circuit constructed with SX1308, a stable 5V and -5V are output to power the system.

[0035] refer to Figure 5 This is a TP4056 lithium battery charging circuit. It is used to charge a single lithium battery pack. The 5V USB power supply provides power to the chip. D14 and D15 are charging indicator lights. R45 is used to set the charging current. C33 is the output filter capacitor for battery charging.

[0036] refer to Figure 6 This is an electronic load constant current circuit. It is used for numerically controlled constant current, enabling the setting of a numerically controlled electronic constant current for the circuit under test. After applying a load to the circuit under test, its load-carrying capacity is tested, achieving functional verification. The constant current circuit mainly uses a U15 LM321 operational amplifier, Q5 NMOS transistor, Q5 ANMOS transistor, and R64 current sampling alloy resistor. Q3 is an NMOS transistor used for the output shutdown circuit. When a constant current of 0mA is required, Q3 NMOS transistor conducts, pulling the output low and achieving shutdown. DAC_A1 is the constant current setting voltage; controlling this voltage allows the setting of the constant current value.

[0037] refer to Figure 7 This is the LCD screen circuit. A GMT024 LCD screen is used, and Q15, R89, R88, R87, and C39 constitute the backlight driver circuit. The MCU main control chip communicates with the LCD screen via the IIC interface.

[0038] refer to Figure 8This is a USB interface circuit. It uses a USB Type-C interface for device charging and data exchange.

[0039] refer to Figure 9 The main control circuit uses ST's 32-bit microcontroller STM32F407ZGT6 to perform detection and control operations on the device.

[0040] During operation, the tester sets the target test current (e.g., 1.5A) via the LCD screen. The device connects to the drive signal terminal of the solenoid valve under test through the input interface. The MCU controls the electronic load circuit to draw the set constant current, and at the same time reads the actual current value through the current detection circuit. If the load-carrying capacity of the power supply under test is normal, its output voltage will be stable within the allowable range, and the actual current value will be consistent with the set value. If the load-carrying capacity of the power supply under test is insufficient, its output voltage will drop sharply, causing the actual current to fail to maintain the set value. The test results and key data will be clearly displayed on the LCD screen, and can be prompted by audible and visual alarms.

[0041] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A device for testing the load-carrying capacity of a solenoid valve drive signal for an FAS gas cylinder, characterized in that, This includes the MCU main control circuit, the electronic load constant current circuit, the current detection circuit, and the output shutdown circuit; The input terminal of the electronic load constant current circuit is used to connect to the drive signal of the solenoid valve under test, and its output terminal is grounded. The current detection circuit is connected in series in the input circuit of the electronic load constant current circuit to collect the current value flowing through the electronic load constant current circuit and transmit the collected signal to the MCU main control circuit. The output terminal of the MCU main control circuit is connected to the control terminal of the electronic load constant current circuit, and is used to output a constant current setting signal to the electronic load constant current circuit; The control terminal of the output shutdown circuit is connected to the MCU main control circuit, and its output terminal is connected to the control terminal of the electronic load constant current circuit. It is used to receive instructions from the MCU main control circuit and can clear the constant current value of the electronic load constant current circuit to zero.

2. The device for testing the load-carrying capacity of the FAS gas cylinder solenoid valve drive signal according to claim 1, characterized in that, The electronic load constant current circuit includes an operational amplifier, an NMOS transistor, and a current sampling resistor. The non-inverting input of the operational amplifier receives a constant current setting signal from the MCU main control circuit, its inverting input is connected to the source of the NMOS transistor, and its output is connected to the gate of the NMOS transistor. The drain of the NMOS transistor serves as the input of the electronic load constant current circuit, and the current sampling resistor is connected between the source of the NMOS transistor and ground.

3. The device for testing the load-carrying capacity of the FAS gas cylinder solenoid valve drive signal according to claim 2, characterized in that, The output shutdown circuit includes an NMOS transistor whose gate receives the shutdown command from the MCU main control circuit, whose drain is connected to the inverting input of the operational amplifier in the electronic load constant current circuit, and whose source is grounded.

4. The device for testing the load-carrying capacity of the FAS gas cylinder solenoid valve drive signal according to claim 2, characterized in that, The electronic load constant current circuit also includes an NTC thermistor, which is located in the power device area of ​​the electronic load constant current circuit and connected to the MCU main control circuit for acquiring temperature signals.

5. The device for testing the load-carrying capacity of the FAS gas cylinder solenoid valve drive signal according to claim 2, characterized in that, It also includes a human-machine interface, which is connected to the MCU main control circuit and is used to set the constant current value and display the measured current data.

6. The device for testing the load-carrying capacity of the FAS gas cylinder solenoid valve drive signal according to claim 5, characterized in that, It also includes a lithium battery, a battery switching circuit, and a boost circuit; the battery switching circuit is used to control the power supply of the lithium battery to the entire device; the boost circuit is connected to the output terminal of the battery switching circuit and is used to convert the lithium battery voltage into a stable system operating voltage.

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