NOYITO 1-Channel PC817 Optocoupler Isolation Module Optoelectronic Isolator Signal Isolation and Anti-Interference 3-5V 12V 24V (Pack of 2) (24V)

I bought 20 of these to interface a Nayex credit card reader to a car wash. The card reader would output a 5V signal and the car wash required pulling a 12 volt line to ground. To make it reliable, I had to replace the input resistor with a smaller value. I think it was a 1k and I replaced it with a 220 ohm resistor. The resistor value needed depends on the output current required. I expected I'd need to modify it when I bought it. It was easy to modify and all 20 of them have been working perfectly for a year now.

I have no complains at all. The item is entirely as described.

They both worked as expected. The reason I gave only 4 stars is becasue the chip is a TLP785; not a PC817 as the mistakenly statr in thier product description.

The instructions are a bit confusing if you're not familiar with the terminology, but after figuring it out it's worked quite well!

No issues with these

On 4V input there is 90+ Ohms resistance between GND and OUT, 8V has 38+ ohms and 13V has 29 ohms. This is very significant as I tried to switch LED array and they were not as bright as using relays as switch.

both of them had rusted screw terminals right out of the box

Datasheet for a PC817 doesn't match this optocoupler, which is for a TLP785.