optoisolator testing question

[1-3-2-4]

It's been awhile since I had to mess with one but on the collector & emitter side should it be showing open? I have a strong feeling it should not..

 

[kubeek]

Hm, hope you mean when the diode is off - what do you measure on a normal transistor between E and C? If it did not show open it would not be a very good transistor..

 

[kubeek]

double post

 

[1-3-2-4]

It shows open

 

[1-3-2-4]

I was looking at this here and mine does not match up which was why I was asking

**broken link removed**

Never mind they are fine

 

[dr pepper]

If you have 2 meters, connect one as a diode test accros the led side, you should get around 2v, with the diode test still in place measure the reistance of the tranny side, with the black probe to the emitter, should be a few ohms which will turn to infinity when you remove the diode test from the led side.
I use this test on dead smpsu's.