Controlling the relay - When

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I have an AC circuit where I have a relay which I will be controlling.

Is it OK if I turn ON the relay an any time during the AC 50Hz cycle? Or what are the advantages of turning on the relay at zero crossing of the AC signal using a ZCD?

Can someone tell me the advantages with using ZCD and what problems I may face if I don't use ZCD and turn the relay ON at variable times of AC input?
 

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If you are meaning a mechanical relay, there is little point in trying to match zero crossing because the time taken by the mechanism isn't that well defined or repeatable.
For a solid state relay there may be an advantage because switching will occur at low voltage and avoid sudden current spikes and the interference they may cause.

Brian.
 

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Hi,

I guess you are talking about a mechanical relay.
Can you give any link to a site where the zero cross switching of a realy is discussed?
Or: Where is your idea form?

Klaus
 

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Or what are the advantages of turning on the relay at zero crossing of the AC signal
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You didn't mention the load, whether it is well known or if can be of any kind. In the case of inductive ones ( e.g motors ), they will try to keep pushing the current even during the relay contact opening transiction, creating spikes; this is why a zero cross approach is desirable.
 

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