how to test optocoupler using multimeter?

[Zippora]

how to test transistor side of optocoupler using multimeter?

 

[Minder]

If it is the style where the base has a pin, check with the method usually used on the meter diode range.
From base to C & E with reversing polarity of the meter.
M.

 

[Zippora]

Thank you for the reply.
It is 4 pin optocoupler. So only emitter and collector pin is out on transistor side.

 

[HellasTechn]

if it uses a led then you can use the diode setting. again I don't know how to measure the transistor. if it uses a laser then I am not sure how either.

 

[Harald Kapp]

Use a battery and a series resistor to control the LED side (turn it on/off).
Use a multimeter in Ω-range to check conduction of the transistor when LED is on, non-conduction when LED is off. That way you check the full photocoupler, not only one part of it.

If you want/need to qualify the photocoupler in more detail, make the LED curent controllable (controlled current source) and wire the transistor side with load resistor and voltage source. Measure collector current as a function of LED current and compute the current transfer ration Ic/Iled.
Get a datasheet for the photocoupler, these typically show recommended test setups for the component.

 

[Zippora]

Use a battery and a series resistor to control the LED side (turn it on/off).
Use a multimeter in Ω-range to check conduction of the transistor when LED is on, non-conduction when LED is off. That way you check the full photocoupler, not only one part of it.

If you want/need to qualify the photocoupler in more detail, make the LED curent controllable (controlled current source) and wire the transistor side with load resistor and voltage source. Measure collector current as a function of LED current and compute the current transfer ration Ic/Iled.
Get a datasheet for the photocoupler, these typically show recommended test setups for the component.

Thank you.