Introduction: For ohmmeter testing purpose, an NPN transistor is similar to two diodes back to back, as shown in figure 12b. there exists two PN junctions, base-emitter and base collector. When each of these junctions is forward biased, the positive lead of the ohmmeter must be connected to P material, and the negative lead to the negative N material (Figure 12c). there should be low resistance reading when these junctions are reverse biased, positive lead to N material and negative lead to P material (figure 12d). The PNP transistor can be tested with a similar method, except that the diodes are face to face as shown in figure 12e. this simple test determines if the transistor is shorted or open on a go (no problems)/no go (it has problems) basis.
Introduction:
For ohmmeter testing purpose, an NPN transistor is similar to two diodes back to back, as shown in figure 12b. there exists two PN junctions, base-emitter and base collector. When each of these junctions is forward biased, the positive lead of the ohmmeter must be connected to P material, and the negative lead to the negative N material (Figure 12c). there should be low resistance reading when these junctions are reverse biased, positive lead to N material and negative lead to P material (figure 12d).
The PNP transistor can be tested with a similar method, except that the diodes are face to face as shown in figure 12e. this simple test determines if the transistor is shorted or open on a go (no problems)/no go (it has problems) basis.
Step by step
Solved in 2 steps