Two wire PIR (powered by load)
Added 2025-02-09 04:24:28 +0000 UTCThe circuitry in this is quite sophisticated. It has two ways to power itself whether the load it is switching is on or off.
The most complicated bit is that if the load is on then normally there would be no voltage across an ordinary switch to power any circuitry. So it snaffles a bit of power at each crossing point of the sinewave.
https://www.youtube.com/watch?v=obk4CZGUW2U
Comments
I always screw that bit of circuitry up. I'm too used to being pampered by the dedicated voltage regulators.
Big Clive
2025-02-12 04:06:32 +0000 UTChi clive, i'm still around although you don't see me on twitch where I still have a sign in issue although I still watch every one of your live streams there. by the way the emitter voltage is less than the base zener voltage due to the junction not plus. just to let you know i'm still awake and attentive.
george spilling
2025-02-10 00:38:36 +0000 UTCMaybe a British thing. Snaffling a cookie off a plate.
Big Clive
2025-02-09 12:41:25 +0000 UTCThe 470K resistor suggests a max of 0.5mA and the low quiescent current of the PIR chip probably means it will be much lower.
Big Clive
2025-02-09 12:40:49 +0000 UTCthat standby power part was far more simple than expected, but vertainly doing the trick. can you measure the standby power draw (mA rms and peak)?
adorfer
2025-02-09 09:53:25 +0000 UTCThat's kind of amazing. Thanks Big Clive. So it's drawing some super tiny current but not enough voltage or current to make the ghost glow. I wonder if powering one of those super low power E12 bulbs you did an exploration back in October last year would make a ghost? I put four of those E12 filament LEDs in a 2 way ceiling fixture and I think the old cloth and wax wiring has enough capacitance or something to make them glow when the circuit is off (oddly enough, when the circuit is on, they don't light more than a dimly)
Dave Frederick AKA @amorphuc
2025-02-09 05:45:23 +0000 UTC"snaffles"?? Is that one of those Manx things...lol
John Zelinka
2025-02-09 04:34:18 +0000 UTC
