Alternating current withstand voltage leakage current testing device based on phase detection technology

Abstract

The utility model discloses an alternating current withstand voltage leakage current testing device based on a phase detection technology. The alternating current withstand voltage leakage current testing device comprises a first voltage output end, a second voltage output end, a testing line, a phase detection device, an analog-to-digital conversion module and an MCU module, the first voltage output end and the second voltage output end are respectively connected with a tested product through test lines, the input end of the phase detection device is connected with the second voltage output end, the output end of the phase detection device is connected with the input end of the analog-to-digital conversion module, the output end of the analog-to-digital conversion module is connected with the MCU module, and the MCU module is connected with the phase detection device. And the MCU module is connected with the control end of the phase detection device. The utility model provides an alternating current withstand voltage leakage current testing device based on a phase detection technology. The phase detection technology is adopted to eliminate the influence of a capacitive load of a testing line on an alternating current withstand voltage leakage current testing result.

Description

Technical Field

[0001] The utility model relates to an AC withstand voltage leakage current testing device based on phase detection technology, belonging to the field of safety leakage current testing. Background Art

[0002] At present, the AC withstand voltage tester applies a high voltage to both ends of the object under test, and then tests the leakage current. Ideally, the object under test is a pure resistive load, and the leakage current can be directly detected by clamping the two clips of the AC withstand voltage tester on the object under test. However, in actual applications, the object under test and the AC withstand voltage tester need to be connected through a very long test line. The longer the test line, the greater the equivalent capacitance value between the lines. The capacitor has the function of passing AC and blocking DC, so the test result cannot truly reflect the actual leakage current of the object under test. Summary of the invention

[0003] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide an AC withstand voltage leakage current test device based on phase detection technology, which adopts the phase detection technology to eliminate the influence of the capacitive load of the test line on the AC withstand voltage leakage current test result.

[0004] In order to solve the above technical problems, the technical solution of the utility model is:

[0005] An AC withstand voltage leakage current test device based on phase detection technology, comprising a first voltage output terminal, a second voltage output terminal, a test line, a phase detection device, an analog-to-digital conversion module and an MCU module;

[0006] The first voltage output terminal and the second voltage output terminal are respectively connected to the product under test through test lines, the input terminal of the phase detection device is connected to the second voltage output terminal, the output terminal of the phase detection device is connected to the input terminal of the analog-to-digital conversion module, the output terminal of the analog-to-digital conversion module is connected to the MCU module, and the MCU module is connected to the control terminal of the phase detection device.

[0007] Furthermore, the phase detection device comprises a 0-degree phase detector, an input end of the 0-degree phase detector is connected to the second voltage output end, and an output end of the 0-degree phase detector is connected to an input end of the analog-to-digital conversion module.

[0008] Furthermore, the phase detection device further comprises a 90-degree phase detector, an input end of the 90-degree phase detector is connected to the second voltage output end, and an output end of the 90-degree phase detector is connected to an input end of the analog-to-digital conversion module.

[0009] Furthermore, the analog-to-digital conversion module includes an analog-to-digital conversion chip, and the model of the analog-to-digital conversion chip is ADS1251.

[0010] Furthermore, the MCU module includes an MCU chip, and the model of the MCU chip is STM32F407ZET6.

[0011] By adopting the above technical solution, the utility model uses the phase detection vector method to test the leakage current and deduct the influence of the test line, which can correctly test the leakage current of the tested product and significantly improve the accuracy of the withstand voltage leakage current during the customer's test process. It can improve the accuracy of the leakage current test of the customer's product, facilitate the customer to use the AC withstand voltage tester, and extend the test line without restriction. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a principle block diagram of an AC withstand voltage leakage current test device based on phase detection technology of the utility model;

[0013] Figure 2 The utility model is a circuit diagram of the phase detection device. DETAILED DESCRIPTION

[0014] In order to make the content of the utility model more clearly understood, the utility model is further described in detail below based on specific embodiments and in conjunction with the accompanying drawings.

[0015] like Figure 1 As shown, this embodiment provides an AC withstand voltage leakage current test device based on phase detection technology, which includes a first voltage output terminal, a second voltage output terminal, a test line, a phase detection device, an analog-to-digital conversion module and an MCU module.

[0016] The first voltage output terminal and the second voltage output terminal are respectively connected to the product under test through test lines, the input terminal of the phase detection device is connected to the second voltage output terminal, the output terminal of the phase detection device is connected to the input terminal of the analog-to-digital conversion module, the output terminal of the analog-to-digital conversion module is connected to the MCU module, and the MCU module is connected to the control terminal of the phase detection device. The above-mentioned modules in the AC withstand voltage leakage current test device are powered by a power supply module.

[0017] The first voltage output terminal and the second voltage output terminal provide the voltage of the voltage level required for the test to the product under test. After the leakage current is generated, the leakage current is output to the analog-to-digital conversion module after passing through the 0-degree phase detection and 90-degree phase detection of the phase detection device. The analog-to-digital conversion module converts the analog signal into a digital signal and outputs it to the MCU module. After calculation by the MCU module, the AC signal is converted into a complex form, and the complex number is split into a real number and an imaginary number. The leakage current can be calculated through calculation.

[0018] The analog-to-digital conversion module of this embodiment includes an analog-to-digital conversion chip, and the model of the analog-to-digital conversion chip is ADS1251. The MCU module of this embodiment includes an MCU chip, and the model of the MCU chip is STM32F407ZET6.

[0019] like Figure 1 As shown, the phase detection device of this embodiment includes a 0-degree phase detector and a 90-degree phase detector, the input end of the 0-degree phase detector is connected to the second voltage output end, and the output end of the 0-degree phase detector is connected to the input end of the analog-to-digital conversion module. The input end of the 90-degree phase detector is connected to the second voltage output end, and the output end of the 90-degree phase detector is connected to the input end of the analog-to-digital conversion module. Figure 2 As shown in the figure, U405B is the signal input terminal, and the phase detector is composed of the multiplexer chip 74HC4053D and the operational amplifier chip OPA2172. After the AC signal is input, the MCU module controls the opening of the two phase detectors through PD2_0, PD2_1, and PD2_2, and U414A and U414B perform 0 degree and 90 degree detection on the AC signal. After the detection is completed, the signal is output to the analog-to-digital conversion module through U417B.

[0020] The working principle of the AC withstand voltage leakage current test device based on phase detection technology in this embodiment is as follows:

[0021] like Figure 1 As shown, after the power module of the AC withstand voltage leakage current test device is powered on, the first voltage output terminal is first connected to the product under test through a test line, and the second voltage output terminal is not connected to the product under test. After passing through the phase detection device and the analog-to-digital conversion module, the MCU module reads the leakage current I0 on the test line at this time.

[0022] After the test is finished, the first voltage output terminal and the second voltage output terminal are connected to the product under test respectively, and the leakage current Id is read out by the MCU module after passing through the phase detection device and the analog-to-digital conversion module.

[0023] Finally, the MCU module calculates the actual leakage current of the product under test by subtracting I0 from Id.

[0024] The specific embodiments described above further illustrate the technical problems, technical solutions and beneficial effects solved by the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An AC withstand voltage leakage current test device based on phase detection technology, characterized in that: It includes a first voltage output terminal, a second voltage output terminal, a test line, a phase detection device, an analog-to-digital conversion module and an MCU module; The first voltage output terminal and the second voltage output terminal are respectively connected to the product under test through test lines, the input terminal of the phase detection device is connected to the second voltage output terminal, the output terminal of the phase detection device is connected to the input terminal of the analog-to-digital conversion module, the output terminal of the analog-to-digital conversion module is connected to the MCU module, and the MCU module is connected to the control terminal of the phase detection device.

2. The AC withstand voltage leakage current test device based on phase detection technology according to claim 1 is characterized in that: The phase detection device comprises a 0-degree phase detector, the input end of the 0-degree phase detector is connected to the second voltage output end, and the output end of the 0-degree phase detector is connected to the input end of the analog-to-digital conversion module.

3. The AC withstand voltage leakage current test device based on phase detection technology according to claim 1, characterized in that: The phase detection device further comprises a 90-degree phase detector, the input end of the 90-degree phase detector is connected to the second voltage output end, and the output end of the 90-degree phase detector is connected to the input end of the analog-to-digital conversion module.

4. The AC withstand voltage leakage current test device based on phase detection technology according to claim 1, characterized in that: The analog-to-digital conversion module includes an analog-to-digital conversion chip, and the model of the analog-to-digital conversion chip is ADS1251.

5. The AC withstand voltage leakage current test device based on phase detection technology according to claim 1, characterized in that: The MCU module includes an MCU chip, and the model of the MCU chip is STM32F407ZET6.

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