4N35 Optocoupler, DC Input 1 Channel Trans with Base DC Output, 100% Transfer Ratio, 6-Pin, PDIP, 1.2V, 4 mm H x 7 mm W x 7.62 mm L (Pack of 20)

Does what an opto coupler should do. I run them at considerably less than 10ma and they work find.One project was monitoring HVAC signals which as AC. Next time I'll look into FOD814 since they work with AC inputs.

Nicely packaged and a good value. Thank you.

I used a few of these and it isolates the input and output very well. I made many types of circuits with these and tested them with both batteries and ac to dc power sources. I have had no issues whith them using batteries; however, with some ac to dc power sources on the output side it self oscillates a little bit. (I found that can be corrected easilly with a capacitor or two, but that also altered the output slightly as well.) Overall, it is very good, and I would recomend it to anyone who needs an optoisolator.

Used these to opto-isolate a 12v circuit with serial data from an RP2040 that runs 3.3v logic. Serial data read without an issue. So far, no problems. Not using them at high frequencies, so I have no idea how it would work in that scenario.

I used one dead bug to get everything optimized then PCB, perfect.

These were Lite-On brand. They work great - just remember to put current limiting resistors in your circuit prior to the LED emitter.

good

Worked as soon as inserted.