I'm currently looking to buy some opto-isolators, however, I see a lot of different types and I'm not sure what the best choice is. The types I've seen are Regular (no details), Darlington pair, TRIAC, and Zero Cross TRIAC.
The first two I think I understand
Regular Opto-isolator= LED inside turns isolated photo transistor on
Darlington Pair Opto-isolator= Same as regular but with higher gain (therefore higher current transfer ratio)
It's the second two which I'm not so sure about
TRIAC opto-isolator= Same as regular but is bidirectional for AC circuits
Zero Cross TRIAC optoisolator= Zero Cross detection? good for AC dimmers.
I don't understand how the ZCD TRIAC optoisolator works. Is a TRIAC opto-isolator always more advantageous than a regular optoisolator. For example can a MOC3062 (pictured)
be used as a regular DC optoisolator to turn an isolated LED on off with a PWM signal, or would it not work at all since there is no actual zero crossing?