Pulse relay

Thread Starter


Joined Jun 30, 2007
I have the following project:

I have a zigbee node with an MCU and I must make it control an AC (240V - 50Hz) light. I was thinking of implementing a dimming function as well. I found out about triacs on the net but it seems a bit hard to me since I am a total n00b in this area. Therefore, I decided to have only an ON/OFF function. My plan is to simply drive a pulse relay with the MCU, but I am lost concerning the choice of the appropriate relay... I am looking for one which is instantly triggered by the MCU and remains ON until it is triggered again to go off in order to achieve the minimum energy consumption. I think it must be called "pulse non latching relay".

I found this relay but it is not the one I need since it is latching.

Any specific suggestions?

Thanx in advance for any answers.

P.S. If you have any ideas of also including the dimming function, please let me know.


Joined Apr 20, 2004
A latching relay with a coil voltage compatible with your hardwar that can handle the current for the bulbs should meet the first requirement.

As for the dimming, you might want to google the subject and see how your MCU can (with external hardware) be interfaced to do the dimming.

Thread Starter


Joined Jun 30, 2007
Thanx for the reply. I want to control a normal light bulb (60-100W) connected to the mains (240V). I don't think that the coil voltage is an issue since I can trigger it with the use of a transistor. Considering this, could you perhaps indicate a suitable relay because I am totally lost.

Thank you once more.


Joined Jun 30, 2006
"Mechanically held lighting contactor"
You could acquire one of these. Contact GE about how you go about controlling it from a MCU. I'm not too sure how they do it. This takes a 24v coil option but also has a controller module of some sort. I'd think you would use a relay to pulse the 24v on then off to 'flip' the contactor on (if off) and again to turn it off but they're not reall clear in the documentation.

http://www.geindustrial.com/publibrary/checkout/Installation and Instruction|DEH-40460|PDF