PIR sensor AND level adjuster?!

[r6deano]

Afternoon all,

Is there a component available that upon pir detection can increase the power to exterior lighting?

IE turn lights on at night (or even via photocell), a low output to soffit /porch lights. Then upon pir activation, this increases the output to said (dimmable) lights?

Tia
Deano

 

[JohnW2]

Is there a component available that upon pir detection can increase the power to exterior lighting? IE turn lights on at night (or even via photocell), a low output to soffit /porch lights. Then upon pir activation, this increases the output to said (dimmable) lights?

I don't recall having seen standalone detector units which do that, but there are certainly some outdoor PIR/Photocell-controlled lighting units which do what you describe - for example (click here) .

You need to search for "Hi-Lo PIR", or things like that.

Kind Regards, John

 

[r6deano]

I don't recall having seen standalone detector units which do that, but there are certainly some outdoor PIR/Photocell-controlled lighting units which do what you describe - for example (click here) .

You need to search for "Hi-Lo PIR", or things like that.

Kind Regards, John

Thanks John. They're exactly like my neighbours lights, except led. I'm curious as to what components are controlling it all, as it's one bulb, so I can create the set up for soffit/porch lights.

Another (old) suggestion I found was connecting a PIR across a dimmer. The dimmer would set the minimum light level, then the PIR would short it out when activated, giving full brightness.

This was in conjunction with filament lights though, I don't know enough about the internals of a trailing edge dimmer and pir switch as to whether they wouldn't short each other out.....

 

[securespark]

https://asdlighting.com/products/half-lantern-range/half-lantern/

EDIT: Apologies, did not see John's link...

 

[JohnW2]

Thanks John. They're exactly like my neighbours lights, except led. I'm curious as to what components are controlling it all, as it's one bulb, so I can create the set up for soffit/porch lights.

With an LED, I presume that it's pretty trivial. There has to be 'electronics' controlling/limiting the current through the LED element(s), so would take very little extra for the PIR-derived signal to interact with that control system and thereby alter the brightness.

Another (old) suggestion I found was connecting a PIR across a dimmer. The dimmer would set the minimum light level, then the PIR would short it out when activated, giving full brightness. ... This was in conjunction with filament lights though, I don't know enough about the internals of a trailing edge dimmer and pir switch as to whether they wouldn't short each other out.....

I suppose that, at least functionally speaking, that's probably essentially how things designed to do what you want would have worked with incandescent lights (if such things existed then).

What is it that you are wanting to control - is it a 'mains-powered' dimmable LED? If so, it's quite possible that you could get away with what you have just described but it would be a gamble, and would have to be determined 'by experiment', because there's no certainty how the dimmer's electronics would react to having voltage applied to its output (by the PIR) - nor, how the PIR (unless it had a 'relay output') would react to having voltage applied to its output (by the dimmer). You would also presumably have to precede the PIR/dimmer combination with a photocell, if you wanted the dim light only to come on at night. Again a matter for experiment, but you might even get away with simply having a suitable value of capacitor (of adequate AC voltage rating) instead of a dimmer.

... just a few thoughts!

Kind Regards, John

 

[r6deano]

What is it that you are wanting to control - is it a 'mains-powered' dimmable LED?

Looking to have X6 soffit downlights, mains GU10/ integrated.

Thanks for the info. I'm just wondering worse case scenario if applying voltage to either the PIR or the dimmers output would result in a potential hazard - if it's a case of try it, if it works, it works, or try it and it works but 6 hrs later it's on fire

 

[JohnW2]

Thanks for the info. I'm just wondering worse case scenario if applying voltage to either the PIR or the dimmers output would result in a potential hazard - if it's a case of try it, if it works, it works, or try it and it works but 6 hrs later it's on fire

I would think that's an extremely improbable risk. If the electronics of either the dimmer or the PIR didn't like voltage being applied to their outputs (which I suspect is unlikely to be a problem), then I think that it either simply 'would not work' (but not be damaged), or else would 'go bang and then not work'. If it worked initially as desired, it would seem extremely unlikely that there would be any ongoing hazard.

However, that's just me 'thinking aloud' - others may have other/additional thoughts about all this.

Kind Regards, John

 

[SUNRAY]

I used to install units which had 3 bulbs which ran in series all night and parallel on PIR

 

[JohnW2]

I used to install units which had 3 bulbs which ran in series all night and parallel on PIR

Very clever - but I suspect an attempt to engineer an equivalent of that with LEDs (particularly mains-powered ones) would probably be quite challenging!

Kind Regards, John