Mihai on November 20, 2016 at 1: Hi, The MOC3021, is a phototriac coupler, meaning that instead of the phototransistor, it has a phototriac, which is basically a triac with the gate driven by the LED. Hello Jestine, I checked an opto 817 and the photo transistor have no reading both ways. Search for: Like Us On Facebook. Sir, thanks you for your valuable trick in order to check Optoisolator device.
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This is a rubber based glue that takes a litt... Ado on November 14, 2014 at 12: The question is which one is the right testing method? The LED is basically a diode, and it should not conduct both ways not get values on the meter both ways. This site uses Akismet to reduce spam. Mohd Usman February 28, 2015 at 1: In the datasheet example, a 10V DC is connected at the output, so that one can check the variation in voltage with a voltmeter or an oscilloscope.
So this is a bad opto?
Geert Van Droogenbroeck on November 18, 2016 at 11: Mihai on March 18, 2017 at 10: Jestine Yong March 2, 2015 at 9: So i am here reading and I see this article. Good repair, as usual....
Thanks for the easy to follow explanation of how to rest an optocoupler. Pls let me know. For the triac pins 4 and 6 , with no voltage applied to the LED pins 1, 2 , check with an ohmmeter the resistance between pins 4 and 6, it should be high open circuit or at least greater than 1 megohm both ways, and this resistance should go down lower than 500 ohms when voltage is applied to the LED, and should remain low even if the voltage is no longer present on the LED.