Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

AC Mains interrupt activate relay on DC

Status
Not open for further replies.

kevinloh

New Member
I would like a simple schematic of a circuit that will trigger a relay through DC (from batteries) when the mains current is interrupt. Sort of like those emergency lighting that turns on when the mains is cut.

Thanks
 
Last edited:
It might be simpler just to use a relay having a mains-voltage coil and change-over contacts to connect a DC load when the relay drops out?
 
That would be great except that I would like to use what I have right now with me. Which is just a simple relay 12V on one side and 2 terminals on the other side.
 
Something like this? Q2 type, and resistor values, depend on how much current your relay coil needs. Q2 can be a 2N3904 or similar for coil currents up to ~150mA.
View attachment 68351
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top