Subway general signal departure indicator test circuit

Abstract

The utility model discloses a subway communication signal departure indicator test circuit, and belongs to the technical field of Internet of Things detection. Comprising a voltage conversion unit, a power supply input end of the voltage conversion unit is connected with commercial power, a power supply output end of the voltage conversion unit is connected with a voltage input end of a voltage stabilization regulation and control unit, the voltage conversion unit converts alternating current voltage of the commercial power into direct current voltage, and the voltage stabilization regulation and control unit is used for converting direct current voltage of DC310V into stable voltage of DC5V. The power supply output end of the voltage stabilization regulation and control unit is simultaneously connected with the voltage input end of the communication connection unit and the voltage input end of the test unit, the signal input end of the communication connection unit is connected with the signal output end of the test unit, and the signal input end of the test unit is connected with an external departure indicator to be detected. According to the utility model, a program is written according to the on-site actual situation and burnt into the single-chip microcomputer U1, the display of the departure indicator is controlled through a control instruction, the operation is simple, and the function of the departure indicator equipment can be comprehensively and efficiently tested.

Description

Technical Field

[0001] The utility model belongs to the technical field of Internet of Things detection, and in particular relates to a subway number departure indicator test circuit. Background Art

[0002] The departure indicator (DTI) is part of the basic signal equipment of urban rail transit. It has connectors with ATS (automatic train monitoring system), ATO (automatic train operating system), interlocking equipment, etc., and is used to detect train occupancy and send ATP (automatic train protection) information, as well as provide the driver with departure instructions. The departure indicator is mainly controlled by the signal system, and clearly displays the train departure information to the driver or passengers on the platform in the form of lights or display screens.

[0003] At present, the departure indicator (DTI) sent for repair cannot be tested in the team, resulting in the inability to determine the fault phenomenon. It is usually necessary to replace or repair the board to eliminate the above problem. However, since the boards include different types of boards such as system boards, power control modules, communication controllers, Profibus connectors, etc., it brings great obstacles to the maintenance of the boards. If the fault is not repaired, it will affect the driver's judgment on the stop time and the timing of closing the doors to depart. If the fault is repaired, the fault can only be checked by online testing methods. The online testing method can only be performed when the subway is stopped, which affects the normal operation of the train. In response to the above problems, the present application proposes a subway departure indicator test circuit. Utility Model Content

[0004] Purpose of the utility model: to provide a subway number departure indicator test circuit, which solves the above-mentioned problems existing in the prior art.

[0005] Technical solution: A subway train departure indicator test circuit includes a voltage conversion unit, wherein the power supply input end of the voltage conversion unit is connected to the mains, the power supply output end of the voltage conversion unit is connected to the voltage input end of a voltage stabilizing and regulating unit, the voltage conversion unit converts the mains AC220V AC voltage into a DC310V DC voltage, the voltage stabilizing and regulating unit is used to convert the DC310V DC voltage into a stable DC5V voltage, the power supply output end of the voltage stabilizing and regulating unit is simultaneously connected to the voltage input end of a communication connection unit and the voltage input end of a test unit to power the communication connection unit and the test unit, the signal input end of the communication connection unit is connected to the signal output end of the test unit, and the signal input end of the test unit is connected to an external departure indicator to be tested.

[0006] Preferably, the voltage conversion unit includes a connector con1, a current transformer FS1, an adjustable resistor RT, a rectifier bridge D6, an inductor L1 and a capacitor C1, the input end of the connector con1 is connected to the AC power, the output end of the connector con1 is simultaneously connected to one end of the current transformer FS1 and one end of the adjustable resistor RT, the other end of the current transformer FS1 is electrically connected to pin 1 of the inductor L1, the other end of the adjustable resistor RT is electrically connected to pin 4 of the inductor L1, pin 2 of the inductor L1 is electrically connected to pin 1 of the rectifier bridge D6, pin 3 of the inductor L1 is electrically connected to pin 3 of the rectifier bridge D6, pin 4 of the rectifier bridge D6 is electrically connected to the negative electrode of the capacitor C1 and to ground, and pin 2 of the rectifier bridge D6 is simultaneously electrically connected to the positive electrode of the capacitor C1 and the input end of the voltage stabilization control unit.

[0007] Preferably, the voltage stabilizing and regulating unit includes a resistor R13, a resistor R14, a resistor R2, a capacitor C4, a resistor R4, a resistor R11, a resistor R10, a field effect transistor Q1, a resistor R1, a resistor R3, a capacitor C3, a capacitor C8, a diode D1, a diode D2, a chip T1A, a transformer T1, a diode D4, a resistor R9, a photosensitive diode VD1, a capacitor C6, a capacitor C5, a resistor R12, an inductor L2, a resistor R5, a photosensitive diode VD2, a resistor R8, a resistor R7, a voltage stabilizing diode Q2, a capacitor C9, a capacitor CY2 and an optical coupler U2, one end of the resistor R13 is simultaneously connected to the output end of the voltage conversion unit, the resistor R2 and the capacitor C4, and the other end of the resistor R13 is connected to the output end of the voltage conversion unit, the resistor R2 and the capacitor C4, and the other end of the resistor R13 is connected to the output end of the voltage conversion unit, the resistor R2 and the capacitor C4, and the other end of the resistor R13 is connected to the output end of the voltage conversion unit, the resistor R1 One end of the resistor R14 is connected, and the other end of the resistor R14 is electrically connected to the resistor R4 and the pin 5 of the chip T1A at the same time. The other end of the capacitor C4 is electrically connected to the other end of the resistor R2 and the negative electrode of the diode D1 at the same time. The positive electrode of the diode D1 is electrically connected to the drain of the field effect transistor Q1. One end of the resistor R11 is electrically connected to the pin 6 of the chip T1A. The other end of the resistor R11 is electrically connected to the resistor R10 and the gate of the field effect transistor Q1 at the same time. The source of the field effect transistor Q1 is electrically connected to the other end of the resistor R10 and the pin 4 of the chip T1A at the same time. One end of the capacitor C8 is electrically connected to the pin 2 of the chip T1A. One end of the resistor R1 is electrically connected to the pin 3 of the chip T1A. The positive electrode of the capacitor C3 is electrically connected to the pin 5 of the chip T1A. One end of the resistor R3 is electrically connected to pin 4 of the chip T1A, the negative electrode of the capacitor C3 is electrically connected to the capacitor C8, the resistor R1, the other end of the resistor R3 and grounded, the pin 1 of the transformer T1 is electrically connected to the capacitor C4, the pin 2 of the transformer is electrically connected to the positive electrode of the diode D1, the pin 3 of the transformer T1 is electrically connected to the positive electrode of the diode D4, the pin 4 of the transformer T1 is electrically connected to the photosensitive diode VD1, one end of the resistor R9 is electrically connected to the photosensitive diode VD1, the other end of the resistor R9 is electrically connected to the negative electrode of the diode D4, the positive electrode of the capacitor C6 is electrically connected to the resistor R9 and the inductor L2, the negative electrode of the capacitor C6 is electrically connected to the photosensitive diode VD1, the positive electrode of the capacitor C5 is electrically connected to the other end of the inductor L2, the resistor R12 and the inductor L2. A voltage output end is provided, wherein the voltage output end is connected to the communication connection unit and the test unit at the same time, the negative electrode of the capacitor C5 is electrically connected to the negative electrode of the capacitor C6 and the other end of the resistor R12 at the same time, one end of the resistor R5 is electrically connected to the resistor R9 and the photosensitive diode VD2 at the same time, the other end of the resistor R5 is electrically connected to the other end of the photosensitive diode VD2, the voltage zener diode Q2 and the capacitor C9 at the same time, the other end of the capacitor C9 is electrically connected to the voltage zener diode Q2, the resistor R8 and the resistor R7 at the same time, the other end of the resistor R8 is electrically connected to the resistor R12, one end of the capacitor CY2 is electrically connected to the optical coupler U2, the other end of the capacitor CY2 is electrically connected to the voltage zener diode VD2 and the resistor R7 and the external power supply, and the other end of the optical coupler U2 is electrically connected to the pin 2 of the chip T1A.

[0008] Preferably, the communication connection unit includes connector A, connector B, connector C, single-chip microcomputer U1, resistor R20, resistor R21, resistor R22, resistor R23, crystal oscillator Y1, capacitor C20, capacitor C21 and capacitor C22, pin 2 of connector A is electrically connected to pin 2 of connector B and pin 2 of connector C and grounded, one end of resistor R21 is electrically connected to pin 23 of single-chip microcomputer U1 and pin 1 of connector A at the same time, the other end of resistor R21 is electrically connected to resistor R22 and resistor R23 at the same time and externally connected to a power supply, and the other end of resistor R22 is electrically connected to pin 22 of single-chip microcomputer U1 and connector B at the same time. Pin 1 of the single-chip computer U1, the other end of the resistor R23 is electrically connected to pin 21 of the single-chip computer U1 and pin 1 of the connector C at the same time, one end of the crystal oscillator Y1 is electrically connected to capacitor C22 and pin 19 of the single-chip computer U1 at the same time, the other end of the crystal oscillator Y1 is electrically connected to capacitor C21 and pin 18 of the single-chip computer U1 at the same time, the other end of the capacitor C21 is electrically connected to capacitor C22 and grounded, the positive electrode of capacitor C20 is connected to an external power supply, the negative electrode of capacitor C20 is electrically connected to pin 9 of the single-chip computer U1 and resistor R20 at the same time, the other end of the resistor R20 is grounded, and pins 31 and 40 of the single-chip computer U1 are connected to the power supply output end of the voltage stabilizing and regulating unit at the same time.

[0009] Preferably, the test unit includes a chip U3, pin 1 of the chip U3 is electrically connected to pin 10 of the single-chip microcomputer U1, pin 4 of the chip U3 is electrically connected to pin 11 of the single-chip microcomputer U1, pin 8 of the chip U3 is connected to an external power supply, pin 5 of the chip U3 is grounded, pin 8 of the chip U3 is connected to the power supply output end of the voltage stabilizing and control unit, and pins 6 and 7 of the chip U3 are connected to an external belt detection departure indicator.

[0010] Preferably, the single chip microcomputer U1 is a single chip microcomputer of model AT89C51.

[0011] Preferably, the chip U3 is a MAX485 chip.

[0012] Preferably, the chip T1A is a chip of model 63G33A.

[0013] Preferably, the optical coupler U2 is an optical coupler of model EL817.

[0014] Beneficial effect: The utility model relates to a subway departure indicator test circuit. The program is written according to the actual situation on site and burned into the single-chip computer U1. With the cooperation of the test unit, each frame of data sent includes 1 start bit, 8 data bits, 1 check bit and 1 stop bit, and a control instruction is passed to control the display of the departure indicator. The operation is simple, and the function of the departure indicator device can be comprehensively and efficiently tested, which saves manpower and material costs, is easy to use, simplifies the daily maintenance workflow of maintenance personnel, and improves maintenance efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is the circuit diagram of the voltage conversion unit and the voltage stabilizing and regulating unit of the utility model;

[0016] Figure 2 This is a circuit diagram of the communication connection unit of the utility model;

[0017] Figure 3 This is a circuit diagram of a test unit of the utility model. DETAILED DESCRIPTION

[0018] like Figures 1 to 3 As shown, the utility model provides a technical solution: a subway departure indicator test circuit, including a voltage conversion unit, a voltage stabilizing and regulating unit, a communication connection unit and a test unit, the power supply input end of the voltage conversion unit is connected to the mains, the power supply output end of the voltage conversion unit is connected to the voltage input end of the voltage stabilizing and regulating unit, the voltage conversion unit converts the AC220V AC voltage of the mains into a DC310V DC voltage, the voltage stabilizing and regulating unit is used to convert the DC310V DC voltage into a DC5V stable voltage, the power supply output end of the voltage stabilizing and regulating unit is simultaneously connected to the voltage input end of the communication connection unit and the voltage input end of the test unit, for the communication connection unit and the test unit Power supply, the signal input end of the communication connection unit is connected to the signal output end of the test unit, the signal input end of the test unit is connected to the external departure indicator to be tested, according to the actual situation on site, a suitable program is written by computer, and the written program is burned into the single-chip microcomputer U1 through 485 communication, and with the cooperation of the test unit, each frame of data sent includes 1 start bit, 8 data bits, 1 check bit and 1 stop bit, and the control command is passed to control the display of the departure indicator, the operation is simple, and the function of the departure indicator equipment can be comprehensively and efficiently tested, which saves manpower and material costs, is easy to use, simplifies the daily maintenance work flow of maintenance personnel, and improves maintenance efficiency.

[0019] In a further embodiment, the voltage conversion unit includes a connector con1, a current transformer FS1, an adjustable resistor RT, a rectifier bridge D6, an inductor L1 and a capacitor C1, the input end of the connector con1 is connected to the mains, the output end of the connector con1 is simultaneously connected to one end of the current transformer FS1 and one end of the adjustable resistor RT, the other end of the current transformer FS1 is electrically connected to pin 1 of the inductor L1, the other end of the adjustable resistor RT is electrically connected to pin 4 of the inductor L1, pin 2 of the inductor L1 is electrically connected to pin 1 of the rectifier bridge D6, pin 3 of the inductor L1 is electrically connected to pin 3 of the rectifier bridge D6, pin 4 of the rectifier bridge D6 is electrically connected to the negative electrode of the capacitor C1 and grounded, pin 2 of the rectifier bridge D6 is simultaneously electrically connected to the positive electrode of the capacitor C1 and the input end of the voltage stabilization control unit, and with the cooperation of the current transformer FS1, the adjustable resistor RT and the rectifier bridge D6, the AC220V AC voltage of the connected mains is converted into a DC310V DC voltage.

[0020] In a further embodiment, the voltage stabilizing and regulating unit includes a resistor R13, a resistor R14, a resistor R2, a capacitor C4, a resistor R4, a resistor R11, a resistor R10, a field effect transistor Q1, a resistor R1, a resistor R3, a capacitor C3, a capacitor C8, a diode D1, a diode D2, a chip T1A, a transformer T1, a diode D4, a resistor R9, a photosensitive diode VD1, a capacitor C6, a capacitor C5, a resistor R12, an inductor L2, a resistor R5, a photosensitive diode VD2, a resistor R8, a resistor R7, a voltage stabilizing diode Q2, a capacitor C9, a capacitor CY2 and an optical coupler U2, wherein the chip T1A adopts a chip model 63G33A, and the optical coupler U2 adopts a chip model EL81 7, one end of the resistor R13 is simultaneously connected to the output end of the voltage conversion unit, the resistor R2 and the capacitor C4, the other end of the resistor R13 is simultaneously connected to one end of the resistor R14, the other end of the resistor R14 is simultaneously electrically connected to the resistor R4 and the pin 5 of the chip T1A, the other end of the capacitor C4 is simultaneously electrically connected to the other end of the resistor R2 and the cathode of the diode D1, the anode of the diode D1 is electrically connected to the drain of the field effect transistor Q1, one end of the resistor R11 is simultaneously electrically connected to the pin 6 of the chip T1A, the other end of the resistor R11 is simultaneously electrically connected to the resistor R10 and the gate of the field effect transistor Q1, the source of the field effect transistor Q1 is simultaneously electrically connected to the other end of the resistor R10 and the pin 4 of the chip T1A, one end of the capacitor C8 is simultaneously electrically connected to the pin 6 of the chip T1A, the other end of the resistor R11 is simultaneously electrically connected to the resistor R10 and the gate of the field effect transistor Q1, the source of the field effect transistor Q1 is simultaneously electrically connected to the other end of the resistor R10 and the pin 4 of the chip T1A, and the other end of the capacitor C8 is simultaneously electrically connected to the pin 6 of the chip T1A. The end is electrically connected to pin 2 of chip T1A, one end of resistor R1 is electrically connected to pin 3 of chip T1A, the positive electrode of capacitor C3 is electrically connected to pin 5 of chip T1A, one end of resistor R3 is electrically connected to pin 4 of chip T1A, the negative electrode of capacitor C3 is electrically connected to capacitor C8, resistor R1, and the other end of resistor R3 and is grounded, pin 1 of transformer T1 is electrically connected to capacitor C4, pin 2 of transformer is electrically connected to the positive electrode of diode D1, pin 3 of transformer T1 is electrically connected to the positive electrode of diode D4, pin 4 of transformer T1 is electrically connected to photodiode VD1, one end of resistor R9 is electrically connected to photodiode VD1, the other end of resistor R9 is electrically connected to the negative electrode of diode D4, and the positive electrode of capacitor C6 is electrically connected to resistor R9 at the same time. and inductor L2, the negative electrode of capacitor C6 is electrically connected to photosensitive diode VD1, the positive electrode of capacitor C5 is electrically connected to the other end of inductor L2, resistor R12 and the voltage output end at the same time, the voltage output end is simultaneously connected to the communication connection unit and the test unit, the negative electrode of capacitor C5 is electrically connected to the negative electrode of capacitor C6 and the other end of resistor R12 at the same time, one end of resistor R5 is electrically connected to resistor R9 and photosensitive diode VD2 at the same time, the other end of resistor R5 is electrically connected to the other end of photosensitive diode VD2, Zener diode Q2 and capacitor C9 at the same time, the other end of capacitor C9 is electrically connected to Zener diode Q2, resistor R8 and resistor R7 at the same time, the other end of resistor R8 is electrically connected to resistor R12, one end of capacitor CY2 is electrically connected to optical coupler U2,The other end of capacitor CY2 is electrically connected to the voltage stabilizing diode VD2 and resistor R7 as well as the external power supply. The other end of the optocoupler U2 is electrically connected to pin 2 of chip T1A. Through the cooperation of transformer T1 and diode D4, the DC310V DC voltage is converted into a DC5V DC voltage. With the cooperation of capacitor C5, capacitor C6 and inductor L2, the DC5V DC voltage is filtered to ensure that the output DC5V voltage remains stable.

[0021] In a further embodiment, the communication connection unit includes connector A, connector B, connector C, single-chip microcomputer U1, resistor R20, resistor R21, resistor R22, resistor R23, crystal oscillator Y1, capacitor C20, capacitor C21 and capacitor C22. The single-chip microcomputer U1 adopts a single-chip microcomputer of model AT89C51. Pin 2 of connector A is electrically connected to pin 2 of connector B and pin 2 of connector C and grounded. One end of resistor R21 is electrically connected to pin 23 of single-chip microcomputer U1 and pin 1 of connector A at the same time. The other end of resistor R21 is electrically connected to resistor R22 and resistor R23 at the same time and connected to an external power supply. The other end of resistor R22 is electrically connected to pin 22 of single-chip microcomputer U1 and pin 1 of connector B at the same time. The other end of resistor R23 is electrically connected to pin 1 of single-chip microcomputer U1 at the same time. 21 and pin 1 of connector C, one end of crystal oscillator Y1 is electrically connected to capacitor C22 and pin 19 of single-chip microcomputer U1 at the same time, the other end of crystal oscillator Y1 is electrically connected to capacitor C21 and pin 18 of single-chip microcomputer U1 at the same time, the other end of capacitor C21 is electrically connected to capacitor C22 and grounded, the positive pole of capacitor C20 is externally connected to power supply, the negative pole of capacitor C20 is electrically connected to pin 9 of single-chip microcomputer U1 and resistor R20 at the same time, the other end of resistor R20 is grounded, pin 31 and pin 40 of single-chip microcomputer U1 are connected to the power supply output end of voltage stabilizing and regulating unit at the same time, provide signal under the cooperation of connector A, connector B and connector C, cooperate with resistor R21, resistor R22 and resistor R23 to ensure stable and reliable triggering, and establish communication connection with the test unit by using pin 10 and pin 11 of single-chip microcomputer U1.

[0022] In a further embodiment, the test unit includes a chip U3, and the chip U3 adopts a chip model MAX485. Pin 1 of the chip U3 is electrically connected to pin 10 of the single-chip computer U1, pin 4 of the chip U3 is electrically connected to pin 11 of the single-chip computer U1, pin 8 of the chip U3 is externally connected to a power supply, pin 5 of the chip U3 is grounded, pin 8 of the chip U3 is connected to a power supply output end of a voltage regulating and controlling unit, pins 6 and 7 of the chip U3 are connected to an external belt detection departure indicator, and a 485 communication connection is established with the single-chip computer U1 through pins 1, 2, 3 and 4 of the chip U3, and pins 6 and 7 of the chip U3 are used to output to the departure indicator to complete the test of the departure indicator.

[0023] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various equivalent transformations can be made to the technical scheme of the present invention, and these equivalent transformations all belong to the protection scope of the present invention.

Claims

1. A subway number departure indicator test circuit, characterized in that: It includes a voltage conversion unit, the power supply input end of the voltage conversion unit is connected to the mains, the power supply output end of the voltage conversion unit is connected to the voltage input end of the voltage stabilizing and controlling unit, the voltage conversion unit converts the AC220V AC voltage of the mains into a DC310V DC voltage, the voltage stabilizing and controlling unit is used to convert the DC310V DC voltage into a stable DC5V voltage, the power supply output end of the voltage stabilizing and controlling unit is simultaneously connected to the voltage input end of the communication connection unit and the voltage input end of the test unit to supply power to the communication connection unit and the test unit, the signal input end of the communication connection unit is connected to the signal output end of the test unit, and the signal input end of the test unit is connected to an external departure indicator to be detected.

2. A subway number departure indicator test circuit according to claim 1, characterized in that: The voltage conversion unit includes a connector con1, a current transformer FS1, an adjustable resistor RT, a rectifier bridge D6, an inductor L1 and a capacitor C1. The input end of the connector con1 is connected to the mains, and the output end of the connector con1 is simultaneously connected to one end of the current transformer FS1 and one end of the adjustable resistor RT. The other end of the current transformer FS1 is electrically connected to pin 1 of the inductor L1, and the other end of the adjustable resistor RT is electrically connected to pin 4 of the inductor L1. Pin 2 of the inductor L1 is electrically connected to pin 1 of the rectifier bridge D6. Pin 3 of the inductor L1 is electrically connected to pin 3 of the rectifier bridge D6. Pin 4 of the rectifier bridge D6 is electrically connected to the negative electrode of the capacitor C1 and is grounded. Pin 2 of the rectifier bridge D6 is simultaneously electrically connected to the positive electrode of the capacitor C1 and the input end of the voltage stabilization and control unit.

3. A subway number departure indicator test circuit according to claim 1, characterized in that: The voltage stabilizing and regulating unit includes a resistor R13, a resistor R14, a resistor R2, a capacitor C4, a resistor R4, a resistor R11, a resistor R10, a field effect transistor Q1, a resistor R1, a resistor R3, a capacitor C3, a capacitor C8, a diode D1, a diode D2, a chip T1A, a transformer T1, a diode D4, a resistor R9, a photosensitive diode VD1, a capacitor C6, a capacitor C5, a resistor R12, an inductor L2, a resistor R5, a photosensitive diode VD2, a resistor R8, a resistor R7, a voltage stabilizing diode Q2, a capacitor C9, a capacitor CY2 and an optical coupler U2. One end of the resistor R13 is simultaneously connected to the output end of the voltage conversion unit, the resistor R2 and the capacitor C4, and the other ... One end of the resistor R14, the other end of the resistor R14 is electrically connected to the resistor R4 and the pin 5 of the chip T1A, the other end of the capacitor C4 is electrically connected to the other end of the resistor R2 and the cathode of the diode D1, the anode of the diode D1 is electrically connected to the drain of the field effect transistor Q1, one end of the resistor R11 is electrically connected to the pin 6 of the chip T1A, the other end of the resistor R11 is electrically connected to the resistor R10 and the gate of the field effect transistor Q1, the source of the field effect transistor Q1 is electrically connected to the other end of the resistor R10 and the pin 4 of the chip T1A, one end of the capacitor C8 is electrically connected to the pin 2 of the chip T1A, one end of the resistor R1 is electrically connected to the pin 3 of the chip T1A, the anode of the capacitor C3 is electrically connected to the pin 5 of the chip T1A, the resistor One end of R3 is electrically connected to pin 4 of chip T1A, the negative electrode of capacitor C3 is electrically connected to capacitor C8, resistor R1, the other end of resistor R3 and grounded, pin 1 of transformer T1 is electrically connected to capacitor C4, pin 2 of transformer is electrically connected to the positive electrode of diode D1, pin 3 of transformer T1 is electrically connected to the positive electrode of diode D4, pin 4 of transformer T1 is electrically connected to photodiode VD1, one end of resistor R9 is electrically connected to photodiode VD1, the other end of resistor R9 is electrically connected to the negative electrode of diode D4, the positive electrode of capacitor C6 is electrically connected to resistor R9 and inductor L2, the negative electrode of capacitor C6 is electrically connected to photodiode VD1, the positive electrode of capacitor C5 is electrically connected to the other end of inductor L2, resistor R12 and voltage Output end, the voltage output end is simultaneously connected to the communication connection unit and the test unit, the negative electrode of capacitor C5 is simultaneously electrically connected to the negative electrode of capacitor C6 and the other end of resistor R12, one end of resistor R5 is simultaneously electrically connected to resistor R9 and photosensitive diode VD2, the other end of resistor R5 is simultaneously electrically connected to the other end of photosensitive diode VD2, voltage regulator diode Q2 and capacitor C9, the other end of capacitor C9 is simultaneously electrically connected to voltage regulator diode Q2, resistor R8 and resistor R7, the other end of resistor R8 is electrically connected to resistor R12, one end of capacitor CY2 is electrically connected to optocoupler U2, the other end of capacitor CY2 is electrically connected to voltage regulator diode VD2 and resistor R7 and an external power supply, and the other end of optocoupler U2 is electrically connected to pin 2 of chip T1A.

4. A subway number departure indicator test circuit according to claim 1, characterized in that: The communication connection unit includes connector A, connector B, connector C, single-chip computer U1, resistor R20, resistor R21, resistor R22, resistor R23, crystal oscillator Y1, capacitor C20, capacitor C21 and capacitor C22, pin 2 of connector A is electrically connected to pin 2 of connector B and pin 2 of connector C and grounded, one end of resistor R21 is electrically connected to pin 23 of single-chip computer U1 and pin 1 of connector A at the same time, the other end of resistor R21 is electrically connected to resistor R22 and resistor R23 at the same time and externally connected to a power supply, the other end of resistor R22 is electrically connected to pin 22 of single-chip computer U1 and pin 1 of connector B at the same time, Pin 1, the other end of the resistor R23 is electrically connected to pin 21 of the single-chip microcomputer U1 and pin 1 of the connector C at the same time, one end of the crystal oscillator Y1 is electrically connected to capacitor C22 and pin 19 of the single-chip microcomputer U1 at the same time, the other end of the crystal oscillator Y1 is electrically connected to capacitor C21 and pin 18 of the single-chip microcomputer U1 at the same time, the other end of the capacitor C21 is electrically connected to capacitor C22 and grounded, the positive pole of capacitor C20 is externally connected to a power supply, the negative pole of capacitor C20 is electrically connected to pin 9 of the single-chip microcomputer U1 and resistor R20 at the same time, the other end of the resistor R20 is grounded, pins 31 and 40 of the single-chip microcomputer U1 are simultaneously connected to the power supply output end of the voltage stabilizing and regulating unit.

5. A subway number departure indicator test circuit according to claim 4, characterized in that: The test unit includes a chip U3, wherein pin 1 of the chip U3 is electrically connected to pin 10 of the single-chip microcomputer U1, pin 4 of the chip U3 is electrically connected to pin 11 of the single-chip microcomputer U1, pin 5 of the chip U3 is grounded, pin 8 of the chip U3 is connected to the power supply output end of the voltage stabilizing and regulating unit, and pins 6 and 7 of the chip U3 are connected to an external belt detection departure indicator.

6. A subway number departure indicator test circuit according to claim 4, characterized in that: The single chip microcomputer U1 is a single chip microcomputer of model AT89C51.

7. A subway number departure indicator test circuit according to claim 5, characterized in that: The chip U3 is a MAX485 chip.

8. A subway number departure indicator test circuit according to claim 3, characterized in that: The chip T1A is a chip of model 63G33A.

9. A subway number departure indicator test circuit according to claim 3, characterized in that: The optical coupler U2 is an optical coupler of model EL817.

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