Electronics › Electronics › How to identify the base collector and emitter of a transistor? › checking transistor using
checking transistor using digital MM.
1: select diode check range
2: fix one lead of DMM (say +ve red lead) with right most terminal of transistor
3: connnect -ve lead (black) of DMM with centre terminal.
4: if DMM show any reading then u have find one PN junction.note that reading.
5: now connect -ve lead with 3rd terminal of transistor.
6: if this also show any reading it means u have found 2nd junction also .note reading of this junction also .
7: the terminal where u connect +ve lead is the base of transistor. and other two terminals middle and left most terminal is collector and emiiter.
8: now u have to differentiate between collector and emiiter.
9: base-emiiter junction has slighlt more resistance then collector.
10: the terminal which has high value is emiiter and other one is collector.
11: if line 6 is not true then fix +ve lead of DMM with middle terminal and check other two terminal with -ve lead. if DMM shows reading with both terminals then follow line8,910..
12: if middle terminal show reading with one terminal and dont show with other terminal then fix +ve lead with 3rd terminal of transistor and repea process.
13: if +ve lead dosent give u any result then repeat this process by -ve lead of DMM.