Capability verification device and method for DC power supply voltage test

Abstract

The invention discloses a capability verification device for a direct-current power supply voltage test, and the device comprises a box body, and a connecting end which is used for being connected with the output end of a test power supply of a to-be-verified laboratory, and is exposed out of the box body. The direct-current voltage stabilizing circuit is arranged in the box body and connected with the connecting end, the analog-to-digital conversion circuit obtains power supply voltage from the direct-current voltage stabilizing circuit, the analog-to-digital conversion circuit continuously reads input voltage on the connecting end, and the input voltage is output to the single-chip microcomputer module after analog-to-digital conversion. The single-chip microcomputer module is preset with threshold voltage, and when the single-chip microcomputer module monitors that the input voltage rises and / or drops to the threshold voltage, the relay and the driving circuit of the relay are controlled to disconnect or connect the power supply circuit of the load, so that the output current of the test power supply jumps. According to the invention, the direct current power supply voltage test capability of a laboratory can be accurately assessed.

Description

Technical Field

[0001] The invention relates to the field of capability verification, in particular to a capability verification device for direct current power supply voltage test, and also to a method for performing capability verification activities using the capability verification device. Background Art

[0002] The voltage of the automotive power system may slowly drop or rise due to various factors (such as battery status, charging status, external environment, etc.), causing functional abnormalities or instability in automotive parts during actual use. For example, excessive voltage may cause damage to components and low voltage may cause failure to drive certain functions, posing a safety hazard to the use of the car. Therefore, automotive parts need to undergo a DC power supply voltage test in accordance with ISO 16750-2:2023 to confirm the performance of automotive parts within the minimum and maximum power supply voltage ranges.

[0003] The traditional DC power supply voltage test is a qualitative test, which can only roughly examine the performance of the product within the specified DC power supply voltage range. There is no document on how to assess the testing capability of laboratories conducting DC power supply voltage tests. Summary of the invention

[0004] The purpose of the present invention is to provide a capability verification device for DC power supply voltage test, by which the capability of a laboratory to conduct DC power supply voltage test can be assessed more accurately.

[0005] The object of the present invention is achieved through the following technical scheme: A capability verification device for a DC power supply voltage test, comprising a box body, a connection end connected to the test power supply output end of a laboratory to be verified, the connection end being exposed from the box body, and also comprising a DC voltage stabilizing circuit arranged inside the box body and connected to the connection end, and an analog-to-digital conversion circuit, a single-chip microcomputer module, a relay and its drive circuit and a load for obtaining a power supply voltage from the DC voltage stabilizing circuit, the analog-to-digital conversion circuit continuously reading the input voltage on the connection end and outputting it to the single-chip microcomputer module after analog-to-digital conversion, the single-chip microcomputer module being preset with a threshold voltage, and when the single-chip microcomputer module monitors that the input voltage rises and / or falls to the threshold voltage, the relay and its drive circuit are controlled to disconnect or connect the power supply circuit of the load, so that the output current of the test power supply jumps.

[0006] The relay and its driving circuit include a relay and a transistor, and the analog-to-digital conversion circuit controls the on / off of the power supply circuit of the load by controlling the on / off of the transistor.

[0007] Since the DC power supply voltage test can only be powered by the laboratory's test power supply, this capability verification device is equipped with a connection terminal for connecting to the test power supply. It is also equipped with a DC voltage stabilizing circuit for converting the linearly changing power supply voltage output by the test power supply into the voltage required for the internal circuit of the capability verification device to work.

[0008] The present invention also provides a method for performing capability verification using the capability verification device, which comprises the following steps:

[0009] The capability verification device is connected to the test power supply of the laboratory to be verified, and the voltage change mode of the test power supply is set according to the standard ISO 16750-2:2023. At the same time, the output end of the test power supply is connected to an oscilloscope to obtain the voltage and current curves of the test power supply output. When the capability verification device detects that the output voltage of the test power supply rises and / or drops to a preset threshold voltage therein, the power supply circuit of the load therein will be disconnected or connected, so that the output current of the test power supply will jump. By comparing the threshold voltage with the voltage value corresponding to the corresponding current jump point in the oscilloscope, the capability of the laboratory to perform DC power supply voltage test is evaluated.

[0010] Compared with the prior art, the present invention has the following advantages:

[0011] The difficulty of the DC power supply voltage test capability verification activity is that the voltage of the test power supply is always in a state of rapid change. The present invention uses a capability verification device to calibrate the actual output voltage of the test power supply, and uses it to stimulate the test power supply output current jump, so as to accurately mark the time point when the calibration voltage is reached, and then obtain the voltage measurement data of the laboratory oscilloscope at the same time point for comparison, and use this to evaluate the test capability of the laboratory, which can more accurately assess the laboratory's ability to conduct DC power supply voltage tests. In addition, the present invention controls the threshold voltage through a single-chip microcomputer module, and can simply adjust the program setting to make the capability verification devices of the present invention have good uniformity. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 A circuit diagram of a capability verification device according to a preferred embodiment of the present invention;

[0013] Explanation of the reference numerals: V1 is the voltage signal input terminal, K01 is a relay, U1 is an ADC0804 analog-to-digital converter, U2 is an STC89C52 single-chip microcomputer, U3 is a voltage regulator, Q2 is a transistor, R1~R10 are resistors, C1~C3 are capacitors, D1~D3 are diodes, and RV1 is a potentiometer. DETAILED DESCRIPTION

[0014] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the following embodiments are only for the purpose of enabling people to have a more thorough understanding of the present invention and should not be construed as limiting the specific implementation manner and protection scope of the present invention.

[0015] The capability verification device for DC power supply voltage test of the present invention comprises a box body and a connection end for connecting to the output end of the test power supply of the laboratory to be verified. The connection end is exposed outside the box body and is used to introduce the output of the test power supply into the box body.

[0016] The capability verification device also includes a DC voltage stabilizing circuit arranged in the box body and connected to the connection end, and an analog-to-digital conversion circuit, a single-chip microcomputer module, a relay and its drive circuit and a load that obtain the power supply voltage from the DC voltage stabilizing circuit. The analog-to-digital conversion circuit continuously reads the input voltage on the connection end and outputs it to the single-chip microcomputer module after analog-to-digital conversion. The single-chip microcomputer module is preset with a threshold voltage. When the single-chip microcomputer module monitors that the input voltage rises and / or drops to the threshold voltage, the relay and its drive circuit are controlled to disconnect or connect the power supply circuit of the load to cause a jump in the output current of the test power supply.

[0017] Figure 1 A specific implementation of the capability verification device of the present invention is given. Figure 1 As shown, in the analog-to-digital conversion circuit of this embodiment, the input voltage (V1) is input to the input end of the analog-to-digital converter ADC0804 after being divided by the resistor R2 and the potentiometer RV1. By changing the resistance value of the potentiometer RV1, the voltage division ratio of the resistor R2 and the potentiometer RV1 can be adjusted, so that the maximum value of the input voltage of the analog-to-digital converter ADC0804 is reduced to the maximum voltage (5V) that can be input to the input end of the analog-to-digital converter.

[0018] Figure 1 The middle point of resistors R3 and R4 is connected to the reference voltage input terminal VREF / 2 of the analog-to-digital converter ADC0804, and the two ends of resistors R3 and R4 are connected to VCC and GND respectively. The reference voltage divided by resistors R3 and R4 is 2.5V, and the actual reference voltage of the analog-to-digital converter is 5V. Since the analog-to-digital converter ADC0804 has an oscillator built in, only capacitor C1 and resistor R1 are needed to form an oscillation circuit. Figure 1 By connecting to the CLKIN and CLKR ports, a clock signal can be provided for the analog-to-digital converter ADC0804.

[0019] Figure 1 The output terminals DB0-DB7 of the analog-to-digital converter ADC0804 are respectively connected to the input terminals P1.0-P1.7 of the single-chip microcomputer STC89C52. The single-chip microcomputer reads the digital signal converted by the analog-to-digital converter, thereby realizing the use of the single-chip microcomputer to capture the voltage input of the signal input terminal.

[0020] In this embodiment, the program of the single-chip computer is set as follows: when the voltage signal at the input end of the single-chip computer is detected to be less than or equal to the preset threshold voltage, the P3.3 output pin of the single-chip computer outputs 0, and at other times outputs 1. The output signal of the single-chip computer P3.3 becomes 0, so that the transistor Q2 enters the conducting state, and then the coil of the relay K01 is energized. The relay K01 operates so that no current flows through the load resistor R10, thereby causing the output current of the laboratory test power supply to drop suddenly.

[0021] The process of conducting proficiency testing activities using the above-mentioned proficiency testing device is as follows:

[0022] Connect the proficiency testing device to the test power supply of the laboratory to be tested, and set the voltage change mode of the test power supply according to the standard ISO 16750-2:2023. Specifically: set the initial voltage to 14V, then increase and decrease at a rate of 1V / s, and change to the minimum supply voltage U Smin , working mode 3 test voltage U A , Maximum supply voltage U Smax Keep a fixed time, and connect the output end of the test power supply to the oscilloscope to obtain the voltage and current curves of the test power supply output. When the single-chip microcomputer detects that the input voltage is less than or equal to the preset threshold voltage, the single-chip microcomputer will send a signal to disconnect the power supply circuit of the load resistor R10, thereby causing the output current of the test power supply to drop suddenly. This phenomenon is recorded by the oscilloscope. The voltage value at the corresponding moment in the oscilloscope can be found based on the current mutation point. By comparing the voltage value with the threshold voltage, the ability of the laboratory to conduct DC power supply voltage tests can be evaluated.

[0023] The change of the microcontroller output pin P3.3 from 1 back to 0 is controlled by the program setting. Obviously, a richer verification process can be achieved by changing the settings in the program, increasing the value or number of the above threshold voltage, or the control logic of rising and falling.

[0024] In general, the present invention uses a capability verification device to calibrate the actual output voltage of the test power supply, and uses it to stimulate the output current jump of the test power supply, so as to accurately mark the time point when the calibration voltage is reached, and then obtains the voltage measurement data of the laboratory oscilloscope at the same time point for comparison, and evaluates the test capability of the laboratory, which can more accurately assess the ability of the actual laboratory to conduct DC power supply voltage tests.

[0025] In addition, the present invention controls the threshold voltage through the single chip microcomputer module, and can simply adjust the program setting to ensure that the capability verification devices of the present invention have good uniformity.

[0026] In addition, it can be seen that to use the proficiency testing device of the present invention to test the test capability of a laboratory, it is only necessary to arrange and test the above-mentioned proficiency testing device in accordance with the requirements of standard ISO 16750-2:2023 and the proficiency testing operating instructions, and the operation is very convenient.

Claims

1. A capability verification device for DC power supply voltage test, characterized in that: It includes a box body, a connection end connected to the output end of the test power supply of the laboratory to be verified, the connection end is exposed from the box body, and also includes a DC voltage stabilizing circuit arranged inside the box body and connected to the connection end, and an analog-to-digital conversion circuit, a single-chip computer module, a relay and its drive circuit and a load for obtaining the power supply voltage from the DC voltage stabilizing circuit. The analog-to-digital conversion circuit continuously reads the input voltage on the connection end and outputs it to the single-chip computer module after analog-to-digital conversion. The single-chip computer module is preset with a threshold voltage. When the single-chip computer module monitors that the input voltage rises and / or drops to the threshold voltage, the relay and its drive circuit are controlled to disconnect or connect the power supply circuit of the load, so that the output current of the test power supply jumps.

2. The capability verification device according to claim 1, characterized in that: The relay and its driving circuit include a relay and a transistor, and the analog-to-digital conversion circuit controls the on / off of the power supply circuit of the load by controlling the on / off of the transistor.

3. A method for capability verification using the capability verification device according to claim 1 or 2, characterized in that it comprises the following steps: connecting the capability verification device to a test power supply of a laboratory to be verified, setting the voltage change mode of the test power supply according to standard ISO 16750-2:2023, and connecting the output end of the test power supply to an oscilloscope to obtain the voltage and current curves output by the test power supply; when the capability verification device detects that the output voltage of the test power supply rises and / or falls to a preset threshold voltage therein, the power supply circuit of the load therein is disconnected or connected, so that the output current of the test power supply jumps; and by comparing the threshold voltage with the voltage value corresponding to the corresponding current jump point in the oscilloscope, the capability of the laboratory to perform a DC power supply voltage test is evaluated.

Images