How does a junction field effect transistor be detected?
The gate G of the junction field effect transistor (JFET) and the source S, the gate G and the drain D have each PN junction, and the gate is symmetrical to the source and drain.
According to this characteristic, the gate G can be accurately determined, and the inlet will determine the source S and the drain D.
(1) determining the electrode and channel of the field-effect transistor, first determine the grid of the tube. Put the multimeter in the RX 100 block and use the black watch pen to touch the electrode of the tube. The red pen will touch the other two electrodes in turn. If the resistance values of the two traceability are very large, it means the P channel field effect tube, and the black pen is connected with the grid. If the value of resistance measured two times is very small, it means the N channel field effect tube, and the black pen is connected with the grid. If there is no such case, the other electrode can be replaced and tested according to the above method until the grid is judged. The source and drain of a junction field effect tube are symmetrical in the manufacturing process, so it can be exchanged to make Sichuan, so the source and drain can no longer be discriminate. The resistance between the drain poles is about 1000 ohms when the resistance is normal.
(2) to estimate the magnification of the field effect transistor, the square meter is placed in the RX100 block, the black pen is connected with the drain pole D, the red pen is connected to the source s. At this time, the pointer indicates the resistance value between the drain and the source, and the hand holds the grid G, the multimeter pointer should have a large swing, the larger the swing, the stronger the magnification of the tube. If the pointer of the multimeter is very small, it shows that the magnifying power of the tube is very weak. If the pointer of the multimeter does not swing at all, it indicates that the tube has lost its magnifying power.
This article is from Allicdata Electronics Limited.
