万用表测三极管（Multimeter for measuring triode）.doc

万用表测三极管（Multimeter for measuring triode） Diode test method: First, assume positive and negative poles, The black one is negative. Readings are one large and one small. (large: near infinity; small: PN junction, forward resistance, several hundred to several thousand European) The hour hypothesis is established. (Hei Zhenghong negative) NPN transistor test method (PNP black, red pen swap): Assuming a base, Black pen up. The red pen, the other two poles, Both are small. (pinky, PN, forward resistance) Conclusion should be three: Type wood and base. C must assume, Black C red meets E. B, C plus bias, Finger is the best. Less resistance, The hypothesis is founded. Type means NPN or PNP; Material means material; Base means base. The first to six sentence is to find the base of the seven to twelve sentence for the area diversity electrode and emitter. A common thyristor in a metal housing (TO - 3) with an anode A. The common pin of the common plastic thyristor (TO - 220) is an anode A, and is mostly connected with a heat sink. Figure 8-15 shows the pin layout of several common thyristors. 2. determine the reverse resistance which is using a multimeter between R * 1K gear measuring common anode A and the cathode of the K transistor, normally should be infinite (infinity) if the measured A and K between positive and negative resistance value is zero or resistance smaller, the thyristor internal short circuit breakdown or leakage. The forward and reverse measure the resistance between gate and cathode of the K G value of normal reverse resistance should be similar to the value of the diode (the actual measurement results are compared with the ordinary diode reverse resistance value, namely small) positive resistance value is small (less than 2 K), reverse resistance value is large (greater than 80 K.). If the resistance values of the two measurements are large or small, then the thyristor G and K poles are open or short circuited. If the positive and negative resistance valu