A programmable power supply and method for testing electrical characteristics of railway safety relays

Abstract

The present invention relates to a programmable power supply and method for testing the electrical characteristics of a railway safety relay, which can output a programmable DC power supply with a programming resolution of 0-15V and 0-5A and can reach 5mV, and provides a low-cost, high-precision, programmable and stable measuring power supply for measuring the electrical characteristics of the current coil of the railway safety relay, and comprises a core processing unit, a power module, a display module, a control module, an output module, a current expansion module, an acquisition module, a communication module, etc. The DC programmable power supply receives an instruction from a host computer to output a voltage through the communication module, and the core processing unit calculates the voltage value to be output into internal control data, and drives the control module to output the control voltage, which is then converted into the voltage to be output by the output module, and the DC programmable power supply collects the output voltage and current values ​​in real time through the acquisition module, and compares them with the set values, so as to achieve a higher-precision output, and at the same time displays the output voltage and current values ​​in real time through the display unit.

Description

Technical Field

[0001] The invention relates to a programmable power supply, in particular to a programmable power supply and a method for testing the electrical characteristics of a railway safety relay. Background Art

[0002] Railway signal relay refers to the electromagnetic switch device used in various railway signal equipment or systems. It is composed of electromagnetic coil, contact group, transmission system and components to ensure the contact is closed or disconnected. The main types are: DC stepless relay, polarity-biased relay, polarity-maintaining relay, etc. When the coil is passed with a calibrated working current, the electromagnet excitation drives the contact system to close the front contact and the middle contact. When the coil is powered off or the current drops to a specified value, the middle contact is disconnected from the front contact and closed with the rear contact by the elastic force of the contact spring and the gravity of the heavy hammer. The purpose of adding a heavy hammer is to ensure that the relay contacts are reliably closed or disconnected from a structural perspective. The gravity or elastic gravity relay used in railway signals in circuits that require fault-oriented safety performance is called a railway signal safety relay.

[0003] Railway signals, as the brain and nerves of commanding traffic, play a very important role in railway transportation. Safety relays are one of the important executive components in railway signal control systems, and their electrical characteristic parameters must be tested regularly before leaving the factory and during use. The main electrical parameters that need to be tested for railway safety relays include: working value, release value, reverse working value, time characteristics, etc. Traditional relay test equipment has low integration, large parameter discreteness, lack of rationality in structural layout, mostly uses semi-automatic measurement or manual measurement, and has poor accuracy and system reliability. Some tests also use programmable power supplies, but the cost of purchasing programmable power supplies is very high. At present, most measurement power supplies are still manually adjusted through voltage regulators and rectifier devices, which are low in intelligence, test accuracy and stability. Summary of the invention

[0004] The object of the present invention is to provide a programmable power supply and method for testing the electrical characteristics of railway safety relays with high precision, low cost and high reliability.

[0005] To this end, the object of the present invention is achieved in this way, and relates to a programmable power supply and method for testing the electrical characteristics of a railway safety relay, which is characterized by comprising: a processing unit, a power module, a display unit, a drive control module, an output module, a current expansion module, a collection module, and a communication module; the output port of the processing unit is electrically connected to the input port of the drive control module and the display unit respectively, is electrically connected to the railway safety relay through the collection module, and is electrically connected to the host computer through the communication module; the power module supplies the +15V, +5V, and -5V power supplies required by the processing unit, the display unit, the drive control module, the output module, the current expansion module, the collection module, and the communication module;

[0006] The power supply module converts the input AC power into +15V, +5V, -5V power required by the entire power supply through a rectifier bridge, a voltage stabilizing circuit and a capacitor;

[0007] The communication module is used to receive the output voltage instruction of the host computer, and the core processing unit calculates the voltage value to be output into internal control data, and drives the control module to output the control voltage, which is then converted into the voltage to be output by the output module;

[0008] The acquisition module is used to collect the output voltage and current values ​​in real time and compare them with the set values ​​to achieve higher precision output;

[0009] The display unit is used to display the output voltage and current values ​​in real time.

[0010] The processing unit adopts PIC16F883.

[0011] The drive control module includes an LTC1451 digital-to-analog conversion chip D1 and an operational amplifier OP-07. The control end of the processing unit is electrically connected to the control end of the LTC1451 digital-to-analog conversion chip D1. The processing unit controls the LTC1451 digital-to-analog conversion chip D1 to output a 0 to 4.096V voltage output. The 0 to 4.096V voltage output by the digital-to-analog conversion chip D1 is electrically connected to the input end of the operational amplifier OP-07, and is amplified by OP-07 and electrically connected to the current expansion module.

[0012] The circuit schematic diagram of the output current expansion module The output current expansion module includes: LM317 and MJ4502, LM317 and MJ4502 are electrically connected, resistors R13 and R14 are connected in parallel between the emitter and base of MJ4502, the emitter of MJ4502 is a 18V DC voltage, which is used to control the turn-on voltage of MJ4502 and also limit the current passing through LM317. Most of the current of the power supply flows through the current expansion tube MJ4502; the signal amplified by OP-07 is electrically connected to the ADJ terminal of LM317 to control the output current of LM317, and the current expansion is realized through Q1 MJ4502.

[0013] A radiator is fixed on the MJ4502.

[0014] The operational amplifier OP-07 is electrically connected to resistors R9, R10, R11, R18, and R19 to form a subtraction circuit. R11 and R18 are 1K input resistors respectively. Resistors R9 and R10 are electrically connected in series to form a voltage divider resistor. One end of resistor R9 is connected to the power supply VCC, and R10 is grounded. The electrical connection point is electrically connected to the negative phase input terminal of the operational amplifier OP-07 through the resistor R18. One end of resistor R11 is electrically connected to the ground, and the other end is electrically connected to the positive phase input terminal of the operational amplifier OP-07. The output of the operational amplifier OP-07 just offsets the 1.25V output of the LM317, and the power supply achieves an output of 0-15V.

[0015] The input and output ends of the LM317 include a diode, and the diode is used to protect the LM317.

[0016] The positive power supply terminal of the operational amplifier OP-07 is connected to positive 15V, and the negative power supply terminal of the operational amplifier OP-07 is connected to negative -5V.

[0017] The acquisition module includes a voltage acquisition part and a current acquisition part. The voltage acquisition part divides the voltage through resistors R20 and R21, and is connected to the D / A measurement interface of the core processing unit after passing through a follower circuit U5 and a low-pass filter circuit; the current acquisition part acquires the voltage across R22 and R23 connected in parallel in the load loop of the output module, and then the operational amplifier circuit U6 amplifies the small voltage, and sends it to the D / A measurement interface of the core processing unit after passing through a bandpass filter at the output end of the operational amplifier circuit U6.

[0018] The working method of the present invention comprises the following process:

[0019] Step 100, start work;

[0020] Step 101, system initialization;

[0021] Step 102, turn on the timing interrupt and serial port interrupt;

[0022] Step 103, reading the current output current in real time;

[0023] Step 104, whether the output current is greater than 2A, if not, return to step 103, if greater, go to step 105;

[0024] Step 105, start timing;

[0025] Step 106, whether the time has reached the set time, if not, wait; if the time has reached, go to step 107;

[0026] Step 107, turn off the output and return to step 103;

[0027] Step 108, the interruption procedure starts;

[0028] Whether the interrupt is one of step 109, step 200, step 201, step 202, and step 203, it is to the relevant interrupt program;

[0029] Interrupt step 109 and start output;

[0030] Step 204, returning an automatic success instruction;

[0031] Step 205, setting the power output, if the setting is empty, then output the original value, otherwise output the set value; return to step 103;

[0032] Interrupt step 200 and stop output;

[0033] Step 206, returning an automatic success instruction;

[0034] Step 207, turn off the power output, and return to step 103;

[0035] Interrupt step 201, set voltage;

[0036] Step 208, returning an automatic success instruction;

[0037] Step 209, if the power supply is in the on state, the currently set voltage is output; if the power supply is in the stop output state, the currently set value is saved to prepare for the next startup, and then return to step 103.

[0038] Interrupt step 202, read voltage;

[0039] Step 210, returning the current voltage or current value, and returning to step 103;

[0040] Interrupt step 203 and read the current;

[0041] Step 210 , returning the current voltage or current value, and returning to step 103 .

[0042] The beneficial effects of the present invention are as follows: the programmable power supply provided by the present invention can output a programmable DC power supply with a programming resolution of 0-15V and 0-5A and a programming resolution of 5mV, and provides a low-cost, high-precision, programmable, and stable measurement power supply for measuring the electrical characteristics of the current coil of a railway safety relay, and includes a core processing unit, a power module, a display module, a control module, an output module, a current expansion module, an acquisition module, a communication module, etc. The DC programmable power supply receives an instruction from a host computer to output a voltage through the communication module, and the core processing unit calculates the voltage value to be output into internal control data, and drives the control module to output the control voltage, which is then converted into the voltage to be output by the output module. The DC programmable power supply collects the output voltage and current values ​​in real time through the acquisition module, and compares them with the set values, so as to achieve a higher-precision output, and at the same time displays the output voltage and current values ​​in real time through the display unit.

[0043] The present invention will be further described in detail below with reference to the accompanying drawings of the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a principle block diagram of the present invention;

[0045] Figure 2 It is the circuit principle diagram of the core processing unit of the present invention;

[0046] Figure 3 is a circuit schematic diagram of a control module of the present invention;

[0047] Figure 4 It is a circuit schematic diagram of the output current expansion module of the present invention;

[0048] Figure 5 It is the circuit principle diagram of the acquisition module of the present invention;

[0049] Figure 6 It is a schematic diagram of the power module circuit of the present invention;

[0050] Figure 7 It is a software flow chart of the core processing unit of the present invention.

[0051] In the figure: 1. Processing unit; 2. Power module; 3. Display unit; 4. Host computer; 5. Drive control module; 6. Output module; 7. Current expansion module; 8. Acquisition module; 9. Communication module. DETAILED DESCRIPTION

[0052] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose, the specific implementation methods, structural features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and embodiments.

[0053] like Figure 1 As shown, the present invention relates to a programmable power supply and method for testing the electrical characteristics of a railway safety relay, which is characterized by comprising: a processing unit 1, a power module 2, a display unit 3, a drive control module 5, an output module 6, a current expansion module 7, a collection module 8, and a communication module 9; the output port of the processing unit 1 is electrically connected to the input port of the drive control module 5 and the display unit 3 respectively, is electrically connected to the railway safety relay through the collection module 8, and is electrically connected to the host computer 4 through the communication module 9; the power module 2 supplies the +15V, +5V, and -5V power supplies required by the processing unit 1, the display unit 3, the drive control module 5, the output module 6, the current expansion module 7, the collection module 8, and the communication module 9;

[0054] The power module 2 converts the input AC power into +15V, +5V, -5V power required by the entire power supply through a rectifier bridge, a voltage stabilizing circuit and a capacitor;

[0055] The communication module 9 is used to receive the output voltage instruction of the host computer, and the core processing unit calculates the voltage value to be output into internal control data, and drives the control module 5 to output the control voltage, which is then converted into the voltage to be output by the output module 6;

[0056] The acquisition module 8 is used to collect the output voltage and current values ​​in real time and compare them with the set values ​​to achieve higher precision output;

[0057] The display unit 3 is used to display the output voltage and current values ​​in real time.

[0058] like Figure 2 , Figure 7 As shown, the processing unit 1 adopts PIC16F883, and PIC16F883 realizes functions such as data communication, analog quantity acquisition, data display, and analog quantity output control through the data bus and the control bus. After the system is initialized, the core processor turns on the timer and serial port functions, waits for receiving instructions, and analyzes the received instructions to start output, stop output, set voltage, read voltage, read current, etc. At the same time, in order to prevent the large current output from burning the equipment, the system enables the timing protection function. When the output current is greater than 2A, if the time exceeds 3 minutes, the power will be automatically cut off.

[0059] like Figure 3 As shown, a circuit diagram of the drive control module 5 is given. The drive control module 5 includes an LTC1451 digital-to-analog conversion chip D1 and an operational amplifier OP-07. The control end of the processing unit 1 is electrically connected to the control end of the LTC1451 digital-to-analog conversion chip D1. The processing unit 1 controls the LTC1451 digital-to-analog conversion chip D1 to output a 0 to 4.096V voltage output. The 0 to 4.096V voltage output by the digital-to-analog conversion chip D1 is electrically connected to the input end of the operational amplifier OP-07, and is amplified by OP-07 and electrically connected to the current expansion module 7.

[0060] like Figure 4As shown, the circuit schematic diagram of the output current expansion module 7 of the present invention includes: LM317 and MJ4502, LM317 and MJ4502 are electrically connected, resistors R13 and R14 are connected in parallel between the emitter and base of MJ4502, the emitter of MJ4502 is a 18V DC voltage, which is used to control the start-up voltage of MJ4502 and also limit the current passing through LM317. Most of the current of the power supply flows through the current expansion tube MJ4502, so a heat sink is fixed on MJ4502, and the signal amplified by OP-07 is electrically connected to the ADJ terminal of LM317 to control the output current of LM317, and the current expansion is realized through Q1MJ4502.

[0061] like Figure 3 As shown, in addition, since the minimum power supply that LM317 can output is 1.25V, which cannot meet the system's 0-15V requirement, a subtraction circuit is formed by resistors R9, R10, R11, R18, R19 and operational amplifier OP-07. R11 and R18 are 1K input resistors respectively. Resistors R9 and R10 are electrically connected in series to form a voltage divider resistor. One end of resistor R9 is connected to the power supply VCC, and R10 is grounded. The electrical connection point is electrically connected to the negative phase input terminal of the operational amplifier OP-07 through resistor R18. One end of resistor R11 is electrically connected to the ground, and the other end is electrically connected to the positive phase input terminal of the operational amplifier OP-07. The output of the operational amplifier OP-07 just offsets the 1.25V output of LM317, and the power supply achieves an output of 0-15V. The diode in the circuit is used to protect LM317. The positive power supply terminal of the operational amplifier OP-07 is connected to positive 15V, and the negative power supply terminal of the operational amplifier OP-07 is connected to negative -5V.

[0062] like Figure 5 As shown, the acquisition module 8 includes a voltage acquisition part and a current acquisition part. The voltage acquisition part divides the voltage through resistors R20 and R21, passes through a follower circuit U5 and a low-pass filter circuit, and is connected to the D / A measurement interface of the core processing unit; the current acquisition part acquires the voltage across R22 and R23 connected in parallel in the load loop of the output module, and then the operational amplifier circuit U6 amplifies the small voltage, and then sends it to the D / A measurement interface of the core processing unit after passing through a bandpass filter at the output end of the operational amplifier circuit U6.

[0063] like Figure 6 As shown, the power module 2 converts the input AC power into +15V, +5V, -5V power required by the entire power supply through a rectifier bridge, a voltage stabilizing circuit and a capacitor;

[0064] The working method of the present invention comprises the following process:

[0065] Step 100, start work;

[0066] Step 101, system initialization;

[0067] Step 102, turn on the timing interrupt and serial port interrupt;

[0068] Step 103, reading the current output current in real time;

[0069] Step 104, whether the output current is greater than 2A, if not, return to step 103, if greater, go to step 105;

[0070] Step 105, start timing;

[0071] Step 106, whether the time has reached the set time, if not, wait; if the time has reached, go to step 107;

[0072] Step 107, turn off the output and return to step 103;

[0073] Step 108, the interruption procedure starts;

[0074] Whether the interrupt is one of step 109, step 200, step 201, step 202, and step 203, it is to the relevant interrupt program;

[0075] Interrupt step 109 and start output;

[0076] Step 204, returning an automatic success instruction;

[0077] Step 205, setting the power output, if the setting is empty, then output the original value, otherwise output the set value; return to step 103;

[0078] Interrupt step 200 and stop output;

[0079] Step 206, returning an automatic success instruction;

[0080] Step 207, turn off the power output, and return to step 103;

[0081] Interrupt step 201, set voltage;

[0082] Step 208, returning an automatic success instruction;

[0083] Step 209, if the power supply is in the on state, the currently set voltage is output; if the power supply is in the stop output state, the currently set value is saved to prepare for the next startup, and then return to step 103.

[0084] Interrupt step 202, read voltage;

[0085] Step 210, returning the current voltage or current value, and returning to step 103;

[0086] Interrupt step 203 and read the current;

[0087] Step 210 , returning the current voltage or current value, and returning to step 103 .

[0088] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A programmable power supply for testing the electrical characteristics of a railway safety relay, characterized in that: include: A processing unit (1), a power module (2), a display unit (3), a drive control module (5), an output module (6), a current expansion module (7), a collection module (8), and a communication module (9); the output port of the processing unit (1) is electrically connected to the input port of the drive control module (5) and the display unit (3), respectively, is electrically connected to a railway safety relay via the current expansion module (7), and is electrically connected to a host computer (4) via the communication module (9); the power module (2) supplies the processing unit (1), the display unit (3), the drive control module (5), the output module (6), the current expansion module (7), the collection module (8), and the communication module (9) with +15V, +5V, and -5V power supplies required by the processing unit (1), the display unit (3), the drive control module (5), the output module (6), the current expansion module (7), the collection module (8), and the communication module (9); The power supply module (2) converts the input AC power into the +15V, +5V, and -5V power supplies required by the entire power supply through a rectifier bridge, a voltage stabilizing circuit, and a capacitor; The communication module (9) is used to receive an instruction from the host computer to output a voltage, and the core processing unit calculates the voltage value to be output into internal control data, and drives the control module (5) to output the control voltage, which is then converted into the voltage to be output by the output module (6); The acquisition module (8) is used to acquire the output voltage and current values ​​in real time and compare them with the set values ​​to achieve higher precision output; The display unit (3) is used to display the output voltage and current values ​​in real time; The drive control module (5) comprises an LTC1451 digital-to-analog conversion chip D1 and an operational amplifier OP-07. The control end of the processing unit (1) is electrically connected to the control end of the LTC1451 digital-to-analog conversion chip D1. The processing unit (1) controls the LTC1451 digital-to-analog conversion chip D1 to output a 0 to 4.096V voltage output. The 0 to 4.096V voltage output by the digital-to-analog conversion chip D1 is electrically connected to the input end of the operational amplifier OP-07, and is amplified by OP-07 and electrically connected to the current expansion module (7). Schematic diagram of the output current expansion module (7) The output current expansion module (7) includes: LM317 and MJ4502, LM317 and MJ4502 are electrically connected, resistors R13 and R14 are connected in parallel between the emitter and base of MJ4502, the emitter of MJ4502 is a 18V DC voltage, which is used to control the turn-on voltage of MJ4502 and also limit the current passing through LM317. Most of the current of the power supply flows through the current expansion tube MJ4502; the signal amplified by OP-07 is electrically connected to the ADJ terminal of LM317 to control the output current of LM317, and the current expansion is realized through Q1 MJ4502.

2. A programmable power supply for testing the electrical characteristics of a railway safety relay according to claim 1, characterized in that: The processing unit (1) adopts PIC16F883.

3. The programmable power supply for testing the electrical characteristics of a railway safety relay according to claim 1, characterized in that: A radiator is fixed on the MJ4502.

4. A programmable power supply for testing the electrical characteristics of a railway safety relay according to claim 1, characterized in that: The amplifier OP-07 is electrically connected to the resistors R9, R10, R11, R18 and R19 to form a subtraction circuit. R11 and R18 are 1K input resistors respectively. The resistors R9 and R10 are electrically connected in series to form a voltage divider resistor. One end of the resistor R9 is connected to the power supply VCC, and R10 is grounded. The electrical connection point is electrically connected to the negative input terminal of the operational amplifier OP-07 through the resistor R18. One end of the resistor R11 is electrically connected to the ground, and the other end is electrically connected to the positive input terminal of the operational amplifier OP-07. The output of the operational amplifier OP-07 just offsets the 1.25V output of the LM317, and the power supply achieves an output of 0-15V.

5. The programmable power supply for testing the electrical characteristics of a railway safety relay according to claim 1, characterized in that: The input and output ends of the LM317 include a diode, and the diode is used to protect the LM317.

6. The programmable power supply for testing the electrical characteristics of a railway safety relay according to claim 1, characterized in that: The positive power supply terminal of the operational amplifier OP-07 is connected to positive 15V, and the negative power supply terminal of the operational amplifier OP-07 is connected to negative -5V.

7. The programmable power supply for testing the electrical characteristics of a railway safety relay according to claim 1, characterized in that: The acquisition module (8) comprises a voltage acquisition part and a current acquisition part. The voltage acquisition part divides the voltage through resistors R20 and R21, passes through a follower circuit U5 and a low-pass filter circuit, and then connects to the D / A measurement interface of the core processing unit; the current acquisition part acquires the voltage across R22 and R23 connected in parallel in the load loop of the output module, and then amplifies the small voltage through the operational amplifier circuit U6, and then sends it to the D / A measurement interface of the core processing unit after passing through a bandpass filter at the output end of the operational amplifier circuit U6.

8. A method for testing the electrical characteristics of a railway safety relay, characterized in that: The process includes: Step 100, start work; Step 101, system initialization; Step 102, turn on the timing interrupt and serial port interrupt; Step 103, reading the current output current in real time; Step 104, whether the output current is greater than 2A, if not, return to step 103, if greater, go to step 105; Step 105, start timing; Step 106, whether the time has reached the set time, if not, wait; if the time has reached, go to step 107; Step 107, turn off the output and return to step 103; Step 108, the interruption procedure starts; Whether the interrupt is one of step 109, step 200, step 201, step 202, and step 203, it is to the relevant interrupt program; Interrupt step 109 and start output; Step 204, returning an automatic success instruction; Step 205, setting the power output, if the setting is empty, then output the original value, otherwise output the set value; Return to step 103; Interrupt step 200 and stop output; Step 206, returning an automatic success instruction; Step 207, turn off the power output, and return to step 103; Interrupt step 201, set voltage; Step 208, returning an automatic success instruction; Step 209, Interrupt step 202, read voltage; Step 210, returning the current voltage or current value, and returning to step 103; Interrupt step 203 and read the current; Step 210 , returning the current voltage or current value, and returning to step 103 , wherein the power supply is based on the programmable power supply according to claim 1 .

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