Method for detecting abnormal voltage output of power adapter

When detecting whether the output voltage of an AC-DC power adapter is abnormal, the following methods can be adopted.

Firstly, a multimeter can be used for detection. Set the multimeter to the DC range and select an appropriate range according to the output voltage of the adapter. For example, the output voltage of some power adapters may be around 19.5V. Place one of the multimeter probes inside the power port and the other outside. The voltage output of the power supply can be displayed. If it matches the nominal value, it is preliminarily judged to be normal. If there is no display, it is abnormal. However, it should be noted that the multimeter can only measure whether the output voltage of the adapter is normal, and the load capacity cannot be directly measured. It can also be judged by observing fault phenomena. If the output voltage of the power adapter is abnormal, it may be manifested as too high or too low output voltage. This may be caused by reasons such as failure of the feedback loop, damage to the voltage reference source, aging or damage of circuit components of the power adapter, excessive load current of the power adapter, and failure of the output voltage regulator of the power adapter. Components such as the feedback loop, voltage reference source, and voltage regulator can be checked, and faulty components can be reconnected or replaced. In addition, checking the interior of the power adapter is also a method.

If there are no problems with the appearance and test, it may be that there is a fault in the internal circuit of the power adapter. At this time, it is necessary to open the power adapter and check whether there are obvious damages or abnormal conditions in the internal circuit board and components. For AC-DC power module testing, the main contents include input characteristic testing, output characteristic testing, thermal characteristic testing, electromagnetic compatibility testing, safety testing, etc. In output characteristic testing, testers need to test parameters such as the output voltage, output current, and output power of the AC-DC power module to ensure that its output characteristics meet the requirements. In conclusion, detecting whether the output voltage of an AC-DC power adapter is abnormal requires the comprehensive application of multiple methods, including using a multimeter for detection, observing fault phenomena, and checking the interior of the power adapter. At the same time, the testing of AC-DC power modules can also provide a reference for detecting power adapters.