how to controle 220vac with 5vdc without using any kind of relays?

Thread Starter

vinay sv

Joined Nov 16, 2020
Someone may please assist with our problem, as I was creating a switching circuit for ac voltage supply where the electronics spacing is very minimal and I need to control my 220v of 300W ac supply with a microcontroller but we couldn't use any relay for it.


Joined Aug 1, 2013
No matter what you call it, there will be some kind of device that is controlled with a low power signal and switches a high power signal. Relay, solid state relay, high-power opto-coupler - whatever. A circuit that uses power MOSFETs will run cooler than any TRIAC circuit, but cost more.

At 220 Vac, 300 W is less than 1.5 A. Nothing you can build from scratch will be smaller or cost less than a 2 A relay.



Joined Feb 3, 2012
Does your 300W AC supply have an isolated "enable/disable" DC signal input?
If so buffer your microcontroller output and drive the enable input low.