AC Relay EMI Suppression

[CocaColaKid]

So basically I should determine what needs to be done and hold that information until the zero cross and then set the relays to there proper state. Is this correct?

[mister_e]

yep. As Ralph suggest, the latches will do the job for you. OR if you don't have many i/o, you can do it by software by checking the zero crossing on a specific i/o and once you get it, refresh your i/o states.

[NavMicroSystems]

If your application allows to do it within the software, fine.
But It will be a bit tricky to get the timing right.

I have given up on the software solution because I had to write to more than one I2C controller at the same time.

With the latches it works just fine.
The only thing you'll need is an option the adjust the trigger-level of the detector to compensate for the relays latency.

[Luciano]

Use a solid state relays (SSR) with built-in zero crossing.

http://www.components.omron.com/Prod...nd_Relays.shtm
(Omron)

http://www.celduc-relais.com/uk/okpac.htm

http://www.power-io.com/
(Ultra precise zero crossing for reduced EMI, without the cost of external filters).

http://www.branom.com/literature/scr.html
(SOLID STATE RELAYS AND SCR POWER CONTROLLERS Introduction).


Luciano