r/blackmagicfuckery • u/Subject-Cheetah802 • Feb 03 '23
What in the world is going on here?
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u/BalkanBorn Feb 03 '23
The charge left over in the capacitors of two working bulbs is flowing back to broken one
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u/ExtemporaneousFrog Feb 03 '23
Yeah something like this. I assume the one on the left is the last one on the circuit. The first two are receiving enough power/current to be lit, but not enough for all three. Once the power is cut, the leftover charge in the capacitors flow to the third bulb lighting it up for a short time. Idk though I’m no electrician.
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u/smac Feb 03 '23
(EE here) Extremely unlikely. It would be a significant safety hazard for a lamp (bulb) to leak current back to the mains. I don't have the code in front of me, but I bet that it would be a violation. Also, most LED lamps use full-wave bridge rectifiers, which are unidirectional, so current can't flow back out.
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u/JohnSolomon46 Feb 04 '23
What is your first sentence even supposed to mean? Are you suggesting the bulbs should dissipate stored power into thin air? Do you realize power can be discharged into the neutral wire on this electrical circuit? Where did you get your electrical engineering degree?
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u/tyboss21 Feb 04 '23
He made no suggestion of it going into thin air, your words not his. he only stated it shouldnt flow backwards. my interpretation of it at least, idk, im not a passive aggressive asshole so could be wrong
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u/bkq1 Feb 04 '23
You got it right. At most the rest of the charge should dissipate having the bulbs stay lit and gradually dim, burning the electricity off. Back flow is bad juju. (Not enough electrical engineer either. Definitely an asshole though.)
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u/JohnSolomon46 Feb 04 '23
Nothing is flowing backwards on the mains wiring, the light switch is turned off.
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u/gusbmoizoos Feb 04 '23
power can be discharged into the neutral wire
Makes me think the left socket is wired in reverse. Not lighting under normal conditions because of the backwards diode, but lighting when the caps discarge from the other two onto the miswired hot/neutral connection of the left one.
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u/smac Feb 04 '23
The diode polarity is not relevant to the AC wiring. The control circuit in the lamp converts the AC to DC and supplies (typically constant current) to the LED(s) in the proper polarity.
The capacitor inside an LED lamp CANNOT discharge to a circuit outside the lamp. If it could, and that bulb were the only thing on the circuit, you could turn off the lamp, unscrew the bulb, and then get a nasty shock from the bulb terminals.
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u/JohnSolomon46 Feb 04 '23
Your comment is the only one on this post that is even remotely correct
The fixture is simply wired wrong from the factory or by the person who installed it, the messed up bulb is wired in series to one of the others and is resulting in exactly what you said.
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u/Weird-Holiday-3961 Feb 03 '23
hmm, i thought left would have been the last one, so it doesn't reach it when you first turn it on, but when turned off, the charge from the 2 bulbs go into the stream and activate Left before emptying completely. Also not an electrician and maybe completely wrong :D
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u/sdfree0172 Feb 03 '23 edited Feb 03 '23
i suppose a smart bulb probably has some capacitance built in, but it wouldn’t be very much. And normal lightbulbs of any kind don’t have capacitance really - They’re best modeled as a resistor or a diode depending on the type. Moreover, those bulbs are in parallel, or at least should be. So, while it looks a bit like a capacitive discharge, I don’t think this is correct. Most likely someone wired the first two bulbs in parallel, but the last in series, and thats causing some odd issues in a smart bulb.
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u/BalkanBorn Feb 03 '23
Bulb is shorted somewhere inside, these fixtures are usually wired in series to save on materials and space
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u/Thisgirl022 Feb 03 '23
I have pretty much the same bulbs and when they're getting ready to burn out they do all kinds of crazy things. Bide your time and have your new ones ready.
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u/lemmefixdat4u Feb 03 '23
I've got an LED bulb in my garage that does EXACTLY this. Turn the power on and it stays off. Turn the power off and it briefly lights. It has a malfunctioning driver circuit. I haven't replaced it because there's a huge pile of stuff under it that my daughter is storing until she moves into her new place.
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u/andthenandthenandthn Feb 03 '23
The one that isn't turning on is wired wrong. LED lights require current to flow in a particular direction. If wired backward will not turn on. When tou turn the switch off it allows back flow of residual current thus turning it on for a brief moment.
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u/JohnSolomon46 Feb 04 '23
You’re wrong this is an AC circuit, LED lights only are affected by polarity in a DC circuit.
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u/throwawayoregon81 Feb 03 '23
Bad led driver. Replace it and move on.
Also, it's know as efm Electrical fucking magic.
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u/psyclopsus Feb 03 '23
Those half globe type of LED bulbs do weird shit when internal components overheat, my bathroom had 3 of them and after about a year one will start to randomly strobe, sometimes come on, sometimes not, I replace it then another starts up
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u/kookookachoobro Feb 04 '23
My bathroom lights so the same thing. Flip the switch on and one doesn’t light up. Flip it off and the same one turns on then dims out.
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u/Express_Information5 Feb 03 '23
Black magic fuckery, or a house fire waiting to happen?
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u/alaettinthemurder Feb 03 '23
They connect it a way when its closed its open singel one that means who connect this is dumb
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u/Flaky_Ad2182 Feb 03 '23
The lamps have a magnetic transmitter to help them not explode basically when you turn those lamps off the electricity current suddenly goes to zero amps So the "life saver" transmitter helps with a magnetic field to add in some electrical current and then that makes a little bit of electricity going through the whole thing so that the electrical current reaches zero slowly preventing a "short touch" like accident which can reduce the lifetime of the lamp but in the other hand the electricity generator (ac power,battery) is disconnected from the circuit and the voltage is zero so all the leftover energy from that magnetically generated current will turn into energy and be used in the last lamp and the furthest from the ac power source.
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u/Emergency-Bowler6851 Feb 03 '23
Wired wrong. That's called a fire hazard. One bulb is wired to the off side of the switch. Not good
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u/wahor73 Feb 03 '23
The bulb on the left has a n auto ight sensor: when it's dark it turns on, when it's light it shuts off.
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u/mienaikoe Feb 03 '23
Think you put in that one bulb backward. Take it out and put it in the other way.
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u/DarkenL1ght Feb 03 '23
Pretty sure you have a close relative in the upsidedown trying to communicate with you.
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u/58curious Feb 03 '23
I have some LED replacement bulbs in my bathroom that have 3 stage illumination. Turn on once: warm white. Turn off and on again: cool white. Third time: dim nightlight. Occasionally, one will loosen a bit from vibration and get out of sync, but off is always off.
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u/Wais5542 Feb 03 '23
Youtuber eletricboom made a video about this I think... Or it was probably Steve Mold.. Or both
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u/Melodic_Trash_737 Feb 04 '23
Isn't this current still in the circuit. LEDs use such little power that even when the switch breaks the circuit the LED still draws down the power. Iys called LED ghosting or something
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u/Nozerone Feb 04 '23
1 out of 3 friends has to be special. Well all know which friend it is too, and if you don't know who it is... I'm sorry.
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u/PristineIntention176 Feb 04 '23
I have issues like this throughout my 1947 house. I should call an electrician? Will he fix it or have to rewire the house? Thousands of dollars? Or just leave a few bulbs out?
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u/Jwirv Feb 03 '23
Two lights turn on while one is off, then the one that wasn't on, turns on when the other two go off. Then the cycle repeats a few times.