The method of distinguishing NPN transistors and PNP transistors using the HFE range of a multimeter
There is a gear on the dial of the multimeter marked with the three letters "HFE" (you can refer to the picture below). It can be said that this gear is specially designed for the transistor. On the upper right corner of the dial, there are eight jacks. The surface of the jacks is marked with some numbers and the types of the tubes. Therefore, we can use these markings to distinguish the types of the transistors being measured.
How to use it? If you know nothing about the transistor at the beginning, you can try to insert the three pins of the transistor into the jacks. If a relatively large and stable number is displayed on the display screen of the multimeter after insertion, then you have inserted it correctly. We can judge according to the information marked at the position of the meter holes. In fact, we also used this point in the previous article. By using this method, not only can we distinguish the type of the tube, but we can also identify the pins of the transistor....
What if there is no relatively large number during the measurement? It doesn't matter. We just need to change the insertion hole of the multimeter or the insertion direction of the transistor until the situation shown in the two pictures above appears. In this way, we can distinguish the type of the tube, and we can even measure the magnification. In fact, the magnification is the number displayed on the display screen of the multimeter.
