Here's a puzzle

dmaavrigdo

dmaavrigdo

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My Satellite Setup
1.2m Laminas OFC1200 dish
Inverto Quad Black Ultra IDLT-QDL412-ULTRA-OPN
Octagon SF8008 twin
Yamaha HTR-2067
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Vansbro Sweden
Small 230 vac LED bulb lit dimly when the power is turned off.
Voltage shown on meter when bulb unscrewed 0 vac.
Voltage shown on meter when bulb screwed in 4.0 Vac.
Discuss or explain.
 

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Last edited:
Bulb being lit by voltage from battery within meter
 
Topper said:
Bulb being lit by voltage from battery within meter
Click to expand...
No the bulb is still lit when the meter is removed,been lit all night.
 
Do you live under a power/transmission line ?
 
Channel Hopper said:
Do you live under a power/transmission line ?
Click to expand...
It's about ten metres from pole mounted 400v lines. Tried the same bulb in a different socket and it doesn't light.Next step is to wander round the house with that bulb in a lamp testing .

Spent some time searching and it seems to be a common occurrence with low wattage LEDs. It's still intriguing that an AC voltage appears when the bulb is inserted.
I'll try a long wire and see if I get free light for the garden.
 
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A 400V supply is not likely to give enough potential for lighting.

An LED diode will give off energy if there is a potential of only 1V or so across the two ends so anything might be causing it, a break of the earth line to the fuse box might create a fluctuating voltage, or 'mains hum' .
 
dmaavrigdo said:
Small 230 vac LED bulb lit dimly when the power is turned off.
Voltage shown on meter when bulb unscrewed 0 vac.
Voltage shown on meter when bulb screwed in 4.0 Vac.
Discuss or explain.
Click to expand...

This brings to mind an occasion when, as a young lad who'd just got his Amateur Radio Licence, I acquired a Heathkit 2W FM Tx/Rx for 2m that had a marked propensity for striking a nearby ceiling mounted Fluorescent Tube and causing it to flicker.
 
Capacitive coupling through the insulation in your household wiring, and a crappy LED driver circuit design that lacks a sufficient discharge resistor across the capacitor inside the lamp to prevent a glow when not powered up... :)
 
Also for....
Usually happens when the neutral is cut and not the active phase.
That is why in the other socket it works well (different socket OK), it interchanges the connections inside the socket.
The internal capacitors to ground, when you turn off the light, are sufficient for that little "leak" and keep "lit" in part.
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Tambien por....
Suele pasar cuando se corta el neutro y no la fase activa.
Por eso en el otro casquillo funciona bien (different socket OK), intercambia las conexiones dentro del casquillo.
Los condensadores internos a masa, cuando apagas la luz, son suficiente para esa pequeña "fuga" y mantienen "encendia" en parte.
 
I agree, the lamp plug or switch is wired backward, switching off the neutral instead of the hot.
 
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