How to Test the Quality of a Power Transistor?

[GabriellaLynn]

To test the quality of a power transistor, you can use a multimeter to measure the inter-electrode resistance to determine its condition. Set the multimeter to the R×100 or R×1K range to measure the forward resistance between the emitter and collector. If the measured forward resistance between the emitter and collector is extremely high or the reverse resistance is very low, it indicates that the power transistor is damaged. Power transistors are the final output tubes in amplification circuits and are categorized into high-power and low-power transistors. Those with a PCM greater than 1W are called high-power transistors, such as domestic models like 3DD and 3DA, or Japanese models like 2SD and 2SC. Those with a PCM less than 1W are called low-power transistors.