hOW TO CHECK A DARLINGTON TRANSISTOR

[avz]

Hello
Do I check a darlington (pnp) transistor whith an ohmmeter just like I check an ordinary transistor, or it has to checked otherwise?
Thanx.

 

[MrAl]

Hi,

You could test to see if it was shorted collector to emitter, but i think the best way would be to bias it with a relatively high value resistor and use another resistor and power supply to check to see if the output transistor turns on and off.

 

[EngIntoHW]

Hi,

Isn't it possible to set the DMM on diode mode, and see double figures than the figures you'd see for a BJT?
for example, about 1.3V-1.4V between base to emitter.

 

[Diver300]

One of the problems with testing a Darlington transistor with a DMM is that they often contain resistors as well as the two transistors. The resistors are there to limit the gain at low currents and to reduce the chance of thermal runaway, so that leakage currents from the first transistor don't get amplified by the second transistor.

The result is that the Darlington transistor is in effect an integrated circuit, and testing it with a DMM is quite difficult.

 

[EngIntoHW]

Got it, thank you Diver.