I’ve a standard energy saving light bulb in a room where I keep my PC, there are no windows in the room, but I’ve noticed the light bulb glows every 30 seconds when turned off? At first I thought it was a reflection from a LED on one of the items of computer gear, so I turned everything off, still happens? No mobile phones or wi-fi / Bluetooth devices / known transmitters in house, so what is making this bulb glow?
2007-05-12 03:29:38 · 11 answers · asked by Avon 7 in Science & Mathematics ➔ Physics
Could be radar if you are near an airport.
2007-05-12 03:35:47 · answer #1 · answered by Anonymous · 0⤊ 0⤋
If the mains isn't coming on periodically, which it probably isn't, then the radar explanation if probably the most likely cause. Early warning radar and radar sweeps from nearby airports can cause this. The other possibilities are -
mains-borne networks - these use high frequency fm signals to transfer network data down the mains cables and can cause problems such as this. I've even seen it when the neighbours have a main network, even though I haven't!
plasma / lightning lamps - these can generate HUGE rf fields that can be felt up to 10 feet away ! If you've got one of these, try holding a neon lamp close to it and see the light show!
neighbours' wireless network - these can transmit up to 300m !
near-by cellular phone masts - miles !
near-by radio masts - 10's to 100's of miles depending on the power
There's probably many other possible causes, when looking just remember, for the bulb to glow the r.f. field must be high frequency.
2007-05-14 01:50:32 · answer #2 · answered by Timbo 3 · 0⤊ 0⤋
The most likely cause IS some form of electromagnetic radiation
Radio Transmitter,
Micro waves
Telephone mast
Radar
( any wire less / remote appliances ?)
They are just fluorescent tubes bent into a different shape
To get them to LIGHT you need a high voltage to strike them
To get them to GLOW you need some form of radiation at higher frequency than that of the Mains ( half submerge one in a cup of water or milk and microwave for 30 sec ...watch through the glass door ..... it will glow from the microwave energy)
2007-05-12 18:52:30 · answer #3 · answered by SPARKFISH 4 · 0⤊ 0⤋
Ah! Mine does that too!
It's most bizzare, but the energy saving bulb in the hallway light flashes every 30 seconds or so also when not switched on.
But the bulb hasn't blown up or anything, so I figured it wasn't that big of a deal.
2007-05-12 03:40:40 · answer #4 · answered by laura_popple 3 · 0⤊ 0⤋
Make sure the light is being switched on and off via the live not the neutral. Also check the switch, cable and fitting for any possible tracking to earth.
2007-05-13 08:04:47 · answer #5 · answered by Anonymous · 0⤊ 0⤋
the radar possibility is interesting.
most likely, it is drawing a tiny amount of current that makes it light up. so tiny that even the leakage current in the return wire is enough.
2007-05-12 10:38:04 · answer #6 · answered by Nirmala 4 · 0⤊ 0⤋
Maybe it's whatever it's connected to. try unplugging it. if not there's probably some kind of inductor inside your lamp giving energy to the bulb.
2007-05-12 03:35:02 · answer #7 · answered by electric 3 · 0⤊ 0⤋
You're missing some power source close by. If what you have is true, you have a perpetual motion machine where you get power for free. That's impossible/
2007-05-12 03:34:25 · answer #8 · answered by Gene 7 · 0⤊ 0⤋
lola, if bulb gets hot enough, thru filament it glows
2016-04-01 08:01:39 · answer #9 · answered by ? 4 · 0⤊ 0⤋
most likely it is still drawing a small amount of power from the fuse.
2007-05-12 03:57:41 · answer #10 · answered by SS4 7 · 0⤊ 1⤋