MOSFET AND BJT Tester

This device is used to test a MOSFET or BJT without having to remove it from the circuit which is connected

This device is used to test a MOSFET or BJT without having to remove it from the circuit which is connected

Project Elements

MOSFET AND BJT TESTER (JPG, 47.4 KB)

COOPER.pdf (PDF)

PCB COOPER SIDE

PARTS.pdf (PDF)

PARTS PLACEMENT

Discussion (3 comments)

John Ott 1 day ago

Is the PCB(or kit) and possibly a case available?
John

0 Comment(s)

C. Nielsen 4 years ago

Nice build. But it would be a good idea, that you to explain how the tester should be used, and the meaning of the 2 LEDs :-)
I think Its pretty simple, but not everyone has the technical background to understand, how the circut works.

Juan.Canton 4 years ago

Basically the tester connects the device to be tested as a switch and injects a square wave in the BASE (GATE) and checks that the corresponding led flashes (LD2 for NPN and NCHANNEL and LD1 for PNP and PCHANNEL), if the led remains on it is indicative that there is a short circuit between COLLECTOR (DRAIN) and EMITTER (SOURCE).
If we connect a NCHANNEL MOSFET with the selector in the PCHANNEL position and the MOSFET has a protection diode LD1 will stay on and vice versa.

1 Comment(s)

ClemensValens 9 years ago

Interesting circuit. Why such a complicated NE555 configuration? Are alle these headers the same?

Regards,
Clemens

Juan.Canton 9 years ago

Yes Clemenns all heads are the same, are set only to support the needles. The two transistors are just to obtain a symmetrical square wave in the 555 output . Thank you for your interest in my circuit Juan Cantón