What are the test items of switching power supply? Specific description and method introduction

Date：2023-02-08 18:23:20Views：736

Chuangxin Testing has always adhered to the purpose of "professional, authoritative, efficient and innovative", purchased international advanced testing equipment with heavy money, and tested in strict accordance with international testing standards and methods. Now it has obtained CNAS certification and international mutual recognition qualification. Its customer base covers many countries and regions at home and abroad. It is a professional IC testing institution with excellent quality and high reputation in China. What are the test items of switching power supply? This article has collected and collated some materials, hoping to be of great reference value to all readers.

1. Repeated short circuit test

Test description

Short-circuit the output of the module under various input and output states. The module should be able to realize protection or retraction. Repeated short circuit. After troubleshooting, the module should be able to automatically resume normal operation.

test method

After retraction and short circuit are eliminated, the module should be able to resume normal operation. Let the module work repeatedly from no-load to short circuit. The short circuit time is 1s, the release time is 1s, and the duration is 2 hours. After this, the short circuit is released to judge whether the module can work normally.

Full load to short circuit: within the full range of input voltage, the module shall be able to realize output current limiting or retraction normally from full load to short circuit. After the short circuit is eliminated, the module shall be able to resume normal operation. Let the module from full load to short circuit and then keep the short circuit for 2 hours. Then release the short circuit and judge whether the module can work normally.

Short-circuit startup: Short-circuit the output of the module, then power it on, and then power it on within the input voltage range of the module. The module should be able to achieve normal current limiting or retraction. After the short circuit fault is eliminated, the module should be able to resume normal operation. After repeating the above test for 10 times, let the short circuit release, and judge whether the module can work normally.

Criteria

After the above tests, the power supply module can work normally after starting; Check whether the circuit board and other parts are normal (such as whether the input relay is stuck in the process of short circuit) and qualified; Otherwise, it is unqualified.

2. Repeated on-off test

Test description

When the power module outputs with maximum load and the input voltage is 220v, (input over-voltage point - 5v) and (input under-voltage point+5v), input the switch repeatedly to test the performance of the power module switch repeatedly.

test method

The input voltage is 220v, and the power module is fast carrying the maximum load. The contactor is used to control the voltage input, which is closed for 15s, and disconnected for 5s (or can be simulated with ac source). The power module should be able to work normally after 2 hours of continuous operation.

The input voltage is over-voltage point - 5v, and the power module carries the maximum load. The contactor controls the voltage input, closes for 15s, and opens for 5s (or can be simulated with ac source). The power module should be able to work normally after 2 hours of continuous operation.

The input voltage is the undervoltage point - 5v. The power module has the maximum load. The contactor is used to control the voltage input, which is closed for 15s, and disconnected for 5s (or can be simulated with ac source). The power module should be able to work normally after 2 hours of continuous operation.

Criteria

In the above tests, the power supply module works normally. After the test, the power supply module can work normally without obvious change in performance, and it is qualified; Otherwise, it is unqualified.

3. Input low voltage point cycle test

Test description

The setting difference of the input undervoltage point protection of the primary power supply module often occurs in the following situations: the input voltage is low, close to the undervoltage point of the primary power supply module is turned off, undervoltage when loaded, and the voltage will rise after the load is removed due to the internal resistance of the power supply, which may cause the primary power supply module to be in the state of repeated development at low voltage.

test method

The power module operates with full load, the input voltage changes slowly from (input undervoltage point - 3v) to (input undervoltage point+3v), the time is set to 5~8 minutes, and the power module should be able to work normally and stably after repeated cycle operation. The power module should operate continuously for at least 0.5 hours, and the performance of the power module has no obvious change.

Criteria

The primary power supply module operates normally and continuously, and its performance has no obvious change after at least 0.5 hours, which is qualified; Otherwise, it is unqualified.

4. Input transient high voltage test

Test description

The pfc circuit uses the average value circuit for over-voltage and under-voltage protection. Therefore, when the transient high voltage is input, the pfc circuit may quickly realize protection, resulting in damage. Test the stable operation ability of the primary power module under transient conditions to evaluate the reliability.

test method

For rated voltage input, test the input voltage waveform and overvoltage protection signal with a dual-trace oscilloscope. The input voltage jumps from 5v to 300v from the power limiting point. Read the cycle number n of 300v before overvoltage protection from the oscilloscope as the basis for the following tests.

With rated input voltage, the power module operates with full load, superimposes 300v voltage jump on the input, the number of superimposed cycles is (n-1), the superimposed frequency is 1 time/30s, and the total operation time is 3 hours.

Criteria

The primary power supply module can operate stably under the above conditions without damage or other abnormal phenomena, and is qualified; Otherwise, it is unqualified.

5. Input low voltage drop and output dynamic load test

Test description

During the actual use of the primary module, when the input voltage drops, the limit condition of sudden load on the power module may occur. At this time, the power devices and magnetic components work in the maximum transient current state. The test can verify the rationality of the control timing, current limiting protection and other circuit and software design.

test method

Adjust the input voltage to jump between the undervoltage point+5v (duration: 5s) and the overvoltage point - 5v (duration: 5s), and adjust the output to jump between the maximum load (maximum rated capacity, duration: 500ms) and the no-load (duration: 500ms) for 1 hour;

Adjust the input voltage to jump between the undervoltage point+5v (duration: 5s) and overvoltage point - 5v (duration: 5s), and adjust the output voltage to jump between the maximum load (maximum rated capacity, duration: 1s) and no-load (duration: 500ms), and operate for 1 hour.

Criteria

Under the above conditions, it shall be able to operate stably without damage or other abnormal phenomena, and it is qualified; Otherwise, it is unqualified. In case of damage, record the fault problem to provide the basis for analyzing the cause of damage.

The above is the relevant content of the switching power supply test organized by the Chuangxin Test, which I hope will help you. Our company has a team of professional engineers and industry elites, and has three standardized laboratories with an area of more than 1800 square meters, which can undertake various test projects such as electronic component testing and verification, IC authenticity identification, product design and material selection, failure analysis, functional testing, factory incoming material inspection and tape weaving.