mettam

I need to check if my Mosfet Transistors are working.
I have read that checking FET (field effect Transistors) with a multimeter can permanently damage the transistor.
Has anyone been able to check Mosfet Transistors using a multimeter ?
I am a newbie so if someone could walk me through the process I would apreciate it.

This is the kind of MultiMeter I have, its called a DVM810 and it does have transistor-checking feature. (link to my multi meter bellow)
http://www.oselectronics.com/Images/pg_5/dvm810.gif

(link to a picture of a Mosfet Transistor)
http://www.robot-italy.com/images/images_med/306002.jpg

awaiting your reply's thank you.

J.

audioguru

The max voltage rating for most Mosfets is 20V from gate to source. When on "diode test" your meter supplies only 3V or less. On "ohms" it supplies about 0.2V.
Static electricity might danage a Mosfet when you connect your meter.

Your meter doesn't supply enough gate voltage to a Mosfet to turn it on for a test. You will need to make a separate Mosfet tester with a 9V battery or something.

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philba

I believe the transisotr checkers on the cheap DMMs are for BJTs, not fets.

Hero999

http://www.uoguelph.ca/~antoon/gadgets/mostest.htm
http://www.4qd.co.uk/serv/mostest.html
http://www.tpub.com/content/neets/14...s/14193_65.htm
http://www.utm.edu/staff/leeb/mostest.htm
http://www.electronics-lab.com/proje...015/index.html
http://www.free-great-info.com/testing-mosfet/
http://www.google.com/search?num=100...ng&btnG=Search

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kchriste

You can do it with the simple "diode check" function built into most digital meters that are powered by 9V batteries:

Short the gate to the source.
Your diode check from drain to source will show an open in one direction and a "diode" in the other.
Connect the meters minus lead to the source.
Unshort the gate and connect the meters positive lead to the gate. It should read open.
Then without touching the gate with anything else, move the meters positive lead to the drain. You shound see a short which will dissappear if you short the gate to the source again.
This may not work with all meters or MOSFETs but it is a quick and easy "go/no-go test.

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user1453

look at
http://www.techlib.com/electronics/spotchecker.htm

atferrari

The text in the first is an exact quote (copy?) from the second.

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