Hello there!

I am searching for the components of garage door opening system.
I have a optocoupler on a IOT device which cannot be directly connected to the contacts on the garage door system.
I need a relay circuit which will be triggered by the IOT device optocouple and here are the specs:

- requires pull-up resistor and external power supply (10mA / max. 50V DC - no AC)
- Output may be loaded with max. 50mA

I am thinking of 12V supply and 34mW coil power relay, but I am not sure if it. Is there a better solution?

Thank you for your time and answers!

 

I am thinking of 12V supply and 34mW coil power relay, but I am not sure if it. Is there a better solution?

That sounds okay.
Make sure you add a diode (e.g. 1N4148) across the relay coil (cathode to plus) to suppress the inductive transient and avoid zapping the opto.

 

Relay modules like the one pictured are cheaper than you can buy parts. They include either a driver transistor or optocoupler so they draw very little current from their's port pin to operate.

Caution: a quick search shows some similar modules without the driver transistor or optocoupler. Look for it in the description for the driver and a part on the circuit board with three or legs.

 

Opto-isolated relay modules are available as somebody has already answered above. If you want to do it from scratch, you can make a circuit like this: https://www.dipelectronicslab.com/relay-module-with-optocoupler/

 

I did use the Arduino relay module and it worked. Thank you all for your suggestions.