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PIR and downlights that fade in/out

Discussion in 'Electrics UK' started by LiGhTfasT, 26 Jul 2018.

  1. LiGhTfasT

    LiGhTfasT

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    I'm looking replace the lights in my porch with a ceiling PIR and 2 downlights. Ideally i'm looking to have the lights build up the brightness over a few seconds instead of instant brightness.

    Any ideas? I've found a PIR and downlights but struggling with the fading.
     
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  3. oldbutnotdead

    oldbutnotdead

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  4. LiGhTfasT

    LiGhTfasT

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    Thanks I did google but its seems a decent product doesn't exist for 240v.

    I'm sure they had nice fade in lighting in star trek in the 90's its a shame we haven't yet caught up. :)
     
  5. oldbutnotdead

    oldbutnotdead

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    There are big boy BMS systems that manage fade in and fade out type stuff. It being LV is a bonus- not as much testing of the wiring required. Easiest way to do it (complete overkill though but wtf) might be a Raspberry Pi to sit between the PIR & the dimmer module to manage the signalling. Or go and talk to your local electrical wholesalers- there may be a PLC out there at a sensible price that'll do the job
     
  6. LiGhTfasT

    LiGhTfasT

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    Thanks i've googled some more and the feature im looking for is "soft start" it looks like a lot of dimmer switches will do this but I'll have to do more digging to see how the PIR will or will not fit in the mix.
     
  7. oldbutnotdead

    oldbutnotdead

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    Problem you'll have with the PIR is most of them make a circuit when activated (throw a relay if you're lucky) and hold that relay until activation ceases plus whatever wait setting you've selected on the thing. The softstart controllers will want a pulse for switchon and another pulse for switchoff (pulse as square as possible and probably minimum 20 milliseconds duration).
     
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  9. ban-all-sheds

    ban-all-sheds

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    Don't you wish you'd stockpiled some of those old school CFLs which took a while to ramp up? Most people had an irrational dislike of them, but they'd be just the ticket.
     
  10. Jakg

    Jakg

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    I have a Varilight Vpro dimmer installed in a loft to dim some downlights, but it's actually controlled from a regular wall switch. It also does the "soft start" slow dimming over about 1.5 seconds. Might be able to put the same between the PIR and the light(s)?

    Doesn't do the opposite when turned off, though.
     
  11. ban-all-sheds

    ban-all-sheds

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    ELV LED bulbs with NTC thermistors in the supply to the bulb?
     
  12. Barlows

    Barlows

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    It may be a bit more that you're looking for but Philips Hue lamps will do this, you can also get their own PIR.
     
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  13. RF Lighting

    RF Lighting

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    Use the switched live from the pir to feed an mk dimmer switch turned on at full that in turn feeds your lights.

    They have a ramp up of about two seconds when power is applied.
     
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  14. LiGhTfasT

    LiGhTfasT

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    Thanks all i'll take a look at the mk dimmer inline option as that sound cheapest and plug and play.
     
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