Switching power supply short circuit is a common fault, easy to burn components, damage equipment, so in the design and manufacturing process of switching power supply often need to test its short circuit protection function. So how to judge whether the switching power supply is short-circuited? What are the factors that affect the short circuit of switching power supply?
A method for detecting whether a switching power supply is short-circuited
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 range, and connect the positive end of the power supply to the positive end of the switching power supply, and connect the negative end of the power supply to the load line. At this time, the value displayed on the ammeter should be 0A, otherwise there is a short circuit problem in the switching power supply.
If the value on the ammeter is 0A, then connect the positive pole of the power supply to the load line, and connect the negative pole of the power supply to the negative pole of the switching power supply, observe the current value displayed by the ammeter, if it is within the normal range, it means that the switching power supply does not have a short circuit problem.
Second, use a multimeter to detect.
It is also necessary to disconnect the power line and load line of the switching power supply first, and then adjust the multimeter to the resistance position, and connect the probe of the multimeter to the output and ground wire of the switching power supply respectively to measure the resistance value. If the resistance value is small, close to zero, it means that there may be a short circuit problem in the switching power supply.
3. Use an oscilloscope to detect the waveform.
Properly connect the oscilloscope and the switching power supply, and detect the waveform with the oscilloscope. If the waveform is very irregular and the hysteresis and skew are large, then there may be a short circuit problem.
Effect of short circuit in switching power supplyFactor.
1. Check the power line.
You need to check whether the power supply line is stable, whether it is correctly connected to the motherboard, graphics card and other devices, and if there is a problem, it needs to be repaired or replaced in time.
2. Check the power switch in the switching 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 normal, it needs to be replaced in time.
3. Check the capacitance of the switching power supply.
If there is a problem with the capacitor, it will also cause a short circuit in the switching power supply, so it is necessary to check whether it is a capacitor problem, and if the capacitor is abnormal, the capacitor needs to be replaced.
4. In addition, it is also necessary to detect other devices, such as motherboards, graphics cards, etc., to detect whether the switching power supply is short-circuited due to abnormality.
Whether the switching power supply is short-circuited can be detected with ammeters, multimeters and oscilloscopes. If a short circuit is found in the switching power supply, the factors causing the short circuit should be investigated in time, and repaired or replaced in time to solve the short circuit problem.