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LED bulb glows even after switched off - Can capacitor help?

patkim

Dec 7, 2017
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Dec 7, 2017
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Hi,

I have a problem exactly as described here

https://forum.allaboutcircuits.com/threads/light-glows-even-after-it-is-switched-off.196906/

I have a 9W 230V AC LED bulb which is connected to a 2-Way circuit and it glows dim even after switch is turned off. I think I know the issue. There are a number of live wires in the concealed duct inside the wall and some capacitive coupling between wires is generating small current in the wire going to the bulb even when switch is off?? This small current is enough to glow the bulb very faintly.

Also the glow stops when I turn off the double pole main circuit breaker that brings live wire inside the house. So in a way it confirms that the source is some live wire in the duct

The solution provided in that thread is to use contact suppressor, but I do not know if such a device is available in my country.

Another solution suggested is to put a 0.2uF 250 V AC capacitor in parallel to the bulb.

So the question is will something like this work?
https://evelta.com/0-22uf-310vac-10-x2-pitch-15mm/

Any other advice is also appreciated.
Thanks.
 

Externet

Aug 24, 2009
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Aug 24, 2009
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900
Actually I like the faint light presence when off. The capacitance between AC lines in proximity is what causes it, microamperes of induction. A resistor of high value or a capacitor of high voltage AC at low value should shunt the behavior. Try the minimal that works and come back with findings.
I added a single white LED (and resistor) to my bathroom ceiling, powered across the wall switch contacts. (night light); I do not have to turn the blinding light at a midnight visit there and allows walking and aiming fine...
 
Last edited:

Bluejets

Oct 5, 2014
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Also the glow stops when I turn off the double pole main circuit breaker that brings live wire inside the house.
Many of these are related to leakage current on the neutral earth in MEN systems.
Replace the single pole switch to the light with one that is double pole (active and neutral) if it bothers you.(or get a qualified lecky to check your installation)
 

patkim

Dec 7, 2017
11
Joined
Dec 7, 2017
Messages
11
Hi All,
Thank you for your suggestions. I bought that 0.22uF 310 V AC capacitor from the link mentioned in my post. Within 24 hours it landed at my home. I have connected that in parallel to the bulb inside the holder. Now the bulb stays completely off and does not glow at all when switch is off. That capacitor did the magic.
The room no longer feels spooky at night!!!
Thanks and regards.
 
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