measure bjt transistor using analog multimeter

how to measure a transistor

hi there.. please give me a tutor step by step how to measure pin E, B, and C of bjt transistors using analog multimeter..

thank you very much

how to measure transistor

What is the parameter u wan to measure? or u jz want to find out which pin is C, B and E?

bjt transistor pins

yup.. right.. i want find out which pin is E, B, and C with analog multimetre, please give me a clear tutor..

thank you

using analog multimeter

turn the meter to ohm scale, try 2 pins at a time until your reading is having low resistance. Then the "+" probe is B, "-" probe is E. Ofcoz, the other pin left is C.

messuring bjt transistor

hi

richloo said:

turn the meter to ohm scale, try 2 pins at a time until your reading is having low resistance. Then the "+" probe is B, "-" probe is E. Ofcoz, the other pin left is C.

Click to expand...

u must atleast know whether it is npn or pnp . in case it is npn then the above said is wrong bcoz the battery is connected in reverse manner inside ....so actually '+' terminal is n-type and vice-versa

regards

determining transistor terminal using multimeter

karthikeya, u r correct. i m assuming npn.

testing bjt with multimeter

thank you richloo how about the FET? how to find out the D, S, and G?? is it the same methode?

case isolated bjt

1. decide NPN or PNP
Daigtal multimeter Red Probe is " +" =P type
Black Probe is " -" =N type
Analog multimeter Red Probe is " _" =P type
Black Probe is " + " =N type

You can decide the transistor is PNP or NPN .

Added after 15 minutes:

I forget write how to decide E B C
You can decide E. B.C .by manual testing.
You know NPN or PNP

example

NPN transistor
presume one pin is C
Connect B and C with your finger ( Rbc, finger is resistor)
Measure the impedance C to E .

and try another pin ,and do the same measurement.

if the resistoer is small ,the C and E is real type .


This testing use Rbc to bias this BJT,the current gain is more than wrong bias(EC is cahnge) .

using analog multimeter to measure current

If your meter has hfe measuring function (most digital ones do, some analog ones do too) then you could just try every possible pin combination (BJT's only of course) until you get a reasonable hfe reading (~100 typically).