Switching power supply testing: exploring the causes and solutions of short circuits in switching power supplies

Date：2024-02-28 17:26:22Views：26

With the rapid development of power electronics technology, switch mode power supplies have been widely used in various fields. During use, the switching power supply may malfunction, and short circuit is one of the more common and serious faults. This article will provide a detailed introduction to how to use scientific methods to determine whether a switching power supply is short circuited, and propose corresponding solutions to the problem of short circuits.

1、 Detect with an ammeter

First disconnect the power line and load line of the switching power supply, then adjust the ammeter to the current gear, and connect the positive pole of the power supply to the positive pole of the switching power supply, and the negative pole of the power supply to the load line. At this point, the value displayed on the ammeter should be 0A, otherwise there is a short circuit problem with the switching power supply.

If the value on the ammeter is 0A, connect the positive pole of the power supply to the load line and the negative pole of the power supply to the negative pole of the switch power supply. Observe the current value displayed on the ammeter. If it is within the normal range, it indicates that there is no short circuit problem with the switch power supply.

2、 Use a multimeter for testing

It is also necessary to disconnect the power line and load line of the switching power supply first, then adjust the multimeter to the resistance gear, connect the probe of the multimeter to the output end and ground wire of the switching power supply respectively, and measure the resistance value. If the resistance value is very small and close to zero, it indicates that there may be a short circuit problem with the switching power supply.

3、 Using an oscilloscope to detect waveforms

Connect the oscilloscope and switch power supply correctly, and use the oscilloscope to detect the waveform. If the waveform is very irregular and the hysteresis and skewness amplitude are large, there may be a short circuit problem.

Factors affecting short circuits in switching power supplies

1、 Check the power circuit

It is necessary to check whether the power line is stable and whether it is connected correctly to the motherboard, graphics card, and other devices. If there are any problems, they need to be repaired or replaced in a timely manner.

2、 Check the power switch in the switch power supply

The power switch is one of the factors that affect the short circuit of the switching power supply. If the power switch is not working properly, it needs to be replaced in a timely manner.

3、 Check the capacitance of the switching power supply

If there is a problem with the capacitor, it can also cause a short circuit in the switching power supply. Therefore, it is necessary to investigate whether it is a problem with the capacitor. If the capacitor is not normal, it needs to be replaced.

4、 In addition, it is also necessary to test other components, such as the motherboard, graphics card, etc., to check if any abnormalities cause a short circuit in the switch power supply.

Summarizing, accurately judging and properly handling the short circuit problem of switching power supplies can not only ensure the stable operation of the equipment, but also effectively extend the service life of the power supply and reduce maintenance costs. I hope the above content can provide valuable reference and guidance for users.