Several Tests and Judgments of Qualified Switching Power Supply

Short-circuit the output of the module under various input and output states, and the module should be able to protect or retract. After repeated short-circuits, the module should be able to automatically resume normal operation after troubleshooting.

1. Repeated short circuit test

Test instruction

Short-circuit the output of the module under various input and output states, and the module should be able to protect or retract. After repeated short-circuits, the module should be able to automatically resume normal operation after troubleshooting.

Test Methods

a. No-load to short-circuit: In the full range of input voltage, the module should be able to achieve output current limiting or retract normally from no-load to short-circuit. After the short circuit is removed, the module should be able to resume normal operation. Let the module work continuously 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 determine whether the module can work normally.

b. Full load to short circuit: In the full range of input voltage, the module should be able to achieve output current limiting or retract normally from full load to short circuit. After the short circuit is removed, the module should be able to resume normal operation. Let the module go from full load to short circuit and then keep the short circuit state for 2 hours. Then release the short circuit to determine whether the module can work normally.

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

judgement standard

After the above test, the Power Module can work normally after booting; check the boot shell, the circuit board and other parts have no abnormal phenomena (such as whether the input relay is stuck in the process of short circuit, etc.), then the design is qualified, otherwise the design is unqualified.

2. Repeated switch test

Test instruction

When the output of the power module is loaded with ZD, the input voltage is 220v, the input overvoltage point is -5v and the input undervoltage point is 5v, the input is switched on and off repeatedly, and the performance of the power module is repeatedly switched on and off.

Test Methods

a. The input voltage is 220v, the power module has a ZD load, and the contactor is used to control the voltage input, close for 15s, disconnect for 5s (or can use ac source for simulation), run continuously for 2 hours, the power module should be able to work normally;

b. The input voltage is overvoltage point -5v, the power module has a ZD load, and the contactor controls the voltage input, closes for 15s, disconnects for 5s (or can use ac source for simulation), and runs continuously for 2 hours, the power module should be normal Work;

c. The input voltage is 5v at the undervoltage point, and the power module has a ZD load. Use a contactor to control the voltage input. Close for 15s and disconnect for 5s (or you can use ac source for simulation). After continuous operation for 2 hours, the power module should be able to work normally. .

judgement standard

In the above test, the power supply module works normally, and the power supply module works normally after the test. If there is no obvious change in performance, it is qualified, otherwise it is unqualified.

3. Enter the low-voltage point cycle test

Test instruction

The YC power module’s input under-voltage point protection is set to hysteresis. The following situations often occur: the input voltage is low, close to the YC power module’s under-voltage point, and the YC power module’s under-voltage point is shut down. The voltage will rise after being dropped, which may cause the YC power module to be in a state of repeated development at low voltage.

Test Methods

The power module runs at full load, the input voltage changes slowly from the input undervoltage point -3v to the input undervoltage point 3v, and the time is set to 5-8 minutes. Repeatedly cyclic operation, the power module should be able to work normally and stably, continuous operation Z less than 0.5 hours, the performance of the power module has no obvious change.

judgement standard

The YC power module runs normally and continuously. If the performance does not change significantly after Z is less than 0.5 hours, it is qualified, otherwise it is unqualified.

4. Input transient high voltage test

Test instruction

The pfc circuit uses an average circuit for over-voltage and under-voltage protection. Therefore, when the transient high voltage is input, the pfc circuit is too fast to achieve protection, but it causes damage. Test the stable operation ability of the YC power module under transient conditions to evaluate the reliability.

Test Methods

a. For rated voltage input, use a dual trace oscilloscope to test the input voltage waveform and overvoltage protection signal. The input voltage jumps from the power limit point to 5v to 300v. Read the number of cycles n of 300v before overvoltage protection from the oscilloscope, as the following The basis of the test.

b. Rated input voltage, the power module runs at full load, a voltage jump of 300v is superimposed on the input, the number of superimposed cycles is (n-1), the superimposed frequency is 1 time/30s, and it runs for a total of 3 hours.

judgement standard

The YC power module can operate stably under the above-mentioned conditions. If there is no damage or other abnormal phenomena, it will be qualified, otherwise it will be unqualified.

5. Input voltage drop and output dynamic load

Test instruction

In the actual use of YC module, when the input voltage drops, the extreme condition of sudden load on the power module may occur. At this time, the power devices and magnetic components are working in the ZD transient current state, and the test can verify the rationality of the circuit and software design such as control timing and current limiting protection.

Test Methods

a. Adjust the input voltage to undervoltage point 5v (duration 5s), overvoltage point -5v (duration 5s) jump between, the output is adjusted to ZD load (ZD rated capacity, duration is 500ms), Jump between no-load (duration of 500ms) and run for 1 hour.

b. Adjust the input voltage to undervoltage point 5v (duration time is 5s), overvoltage point -5v (duration time is 5s), the output is adjusted to ZD load (ZD rated capacity, duration is 1s), Jump between no-load (duration of 500ms) and run for 1 hour.

judgement standard

Under the above conditions, it should be able to operate stably. If there is no damage or other abnormal phenomena, it is qualified, otherwise it is unqualified. In the event of damage, record the failure problem to provide a basis for analyzing the cause of the damage.