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Triac dimmer after PIR sensor

Josh Cook

Hi there,

I am looking at specifying a Triac dimmer switch after a few PIRs and a manual override to control several lights, i dont see an issue why this shouldnt work as the Triac dimmer is after the PIR. Has anyone done something like this before and had issues?

I know its a bit unconventional but should achieve what the client is after.

Thanks

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  • 0

    Take care to select a PIR that has a real relay contact, and is not itself  triac or SCR based- some designs that use a solid state switch do not appreciate the interrupted current that flows through the dimmer and weird flickering is the result at some dimmer settings.


    What you need is the sort of PIRs where you can hear the contacts click -  avoid models described as  'silent' and 'solid state'.
    Mike

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  • 0

    Take care to select a PIR that has a real relay contact, and is not itself  triac or SCR based- some designs that use a solid state switch do not appreciate the interrupted current that flows through the dimmer and weird flickering is the result at some dimmer settings.


    What you need is the sort of PIRs where you can hear the contacts click -  avoid models described as  'silent' and 'solid state'.
    Mike

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  • 0 in reply to mapj1

    Definitely, ... SCRs and triacs generally need a current to keep them switched "on" ... where these (or a modern equivalent) is used in the PIR, it might be "fooled" or "disrupted" by the triac in the dimmer keeping the power off for a portion of the half-cycle.

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