Hi Joe,
First thing to do is look up the part number. IRF Z44 is a fet, not bipolar. Gate, drain and source. The data sheet will identify what the leads are on the device for you.
Fets can give you a false short reading between drain and source depending on the charge stored on the gate. They are static sensitive.
-Chris
First thing to do is look up the part number. IRF Z44 is a fet, not bipolar. Gate, drain and source. The data sheet will identify what the leads are on the device for you.
Fets can give you a false short reading between drain and source depending on the charge stored on the gate. They are static sensitive.
-Chris
argonrepublic said:
When mounted on heatsink with pins down
from left to right:
Gate - Drain - Source
This is corresponding to
Base - Collector - Emitter
for a bipolar
I have found easiest and most qucik way, works really good and free!
to find datasheet on any component
http://datasheetarchive.com/
In this case my search was: RFP50N06
Once you've identified the pinouts and type from the datasheet, you can 99% of the time check they are OK with the diode range of a DVM.
FETs measure as a diode from drain to source with the meter the wrong polarity (compared with normal circuit operation). They usually go short or low resistance when they fail, sometimes open circuit because the short blew open. This is with the FET in circuit when there should be components stopping the gate from floating high and turning the FET on hard, i.e. this method may not work out of circuit.
Transistors measure as 2 diodes from B-E and B-C and will have gain if while you measure the diode reading from B-E you short C-B and the reading falls a little.
FETs measure as a diode from drain to source with the meter the wrong polarity (compared with normal circuit operation). They usually go short or low resistance when they fail, sometimes open circuit because the short blew open. This is with the FET in circuit when there should be components stopping the gate from floating high and turning the FET on hard, i.e. this method may not work out of circuit.
Transistors measure as 2 diodes from B-E and B-C and will have gain if while you measure the diode reading from B-E you short C-B and the reading falls a little.
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