The positive and negative polarity can also be determined by measuring the forward and reverse resistance values of the light-emitting diode usdiodeing the R × lOk range of a multimeter.
The first part represents the number of electrodes in the tube, with the number "3" indicating the transistor.
The resistance range of a multimeter can be used to distinguish the polarity of a transistor and determine its quality
After identifying the base and transistor, determine the emitter and collector. diode
Estimation of current amplification factor: Use a multimeter R × 100 (Q) or R × 1k (Q) to measure the resistance between the collector and emitter of a transistor (for NPN transistors,
Distinguishing between high-frequency and low-frequency tubes: The cutoff frequency of high-frequency tubes is greater than 3 MHz,
