I bought a new desk lamp today from habitat, and very nice it is too. It's all chrome with a half-sphere for a shade, which is also chrome.
Anyway, I plugged it in amongst the zillions of other things that are plugged in under my desk (yes, I'm surge protected), and switched it on. So far, so fine. However, when I switched it off again, my computer speakers made a loud 'pop' noise. I have quite fancy speakers, they have a seperate bass box under the desk, with the two speakers on the desktop, about a metre away from the lamp on each side.
So what is causing the pop? It happens only when I turn the lamp off. Is it the metal, or something to do with the electrics?
Clueless From Birmingham.
Hi there, a few questions about your new lamp
Does the lamp have a normal light bulb fitted?
Does it have a normal switch or one of those touch sensors?
It's one of those screw-in candle bulbs, fairly normal fare. The switch is also normal, and is about 10cm along the wire rather than on the lamp itself.
I don't think its anything to worry about.
The switches used in lamps these days tend to be fairly cheap in construction and can cause some arcing on the contacts, this causes radio interference and is possibly what your amplifier is picking up and sending to the speakers.
Groovy, thanks. I'll just turn my speakers off first before I go to bed, that'll avoid it.Originally Posted by doubting thomas
Yes it sounds like arcing in the switch. It also happens at my office. Whenever a certain switch is turned off there's a loud pop from the computer's speakers. Harmless but annoying.
It also happens when we open and close the fridge. The light switch causes it. >:(
.
Again cheap construction and not enough suppression built into components.
Thats the pay back we get for having lower price goods.
The other thing that often happens comes from mobile phones left near audio
amps that strange bleeping noise caused by the phone logging on to its local transmitter >:(
On reading the thread title my first reaction was "A small explosive charge?"
Seriously;
When I was in Liverpool, if I was at home I could always tell when my mobile was going to ring about 5 seconds before it did because my TV or stereo would go haywire.
Jodrell Bank is a radio quiet zone, there's a big sign at the entrance saying "All mobile phones must be switched off." No please, it's not a request. A couple of years ago they were doing a big survey with the Lovell, and they discovered that the power leads for all the desktops were at a resonant frequency of the wavelength they were using. For two months everyone had to turn of their computers between 10am and 4pm!
Ha ha! Great story. I'd love that, I'd have a real excuse not to do any work instead of the pseudo-excuses I keep inventing. "Ooh, I need to re-grout the bathroom tiles, I'll have to leave this report til tomorrow!"On reading the thread title my first reaction was "A small explosive charge?"
Seriously;
When I was in Liverpool, if I was at home I could always tell when my mobile was going to ring about 5 seconds before it did because my TV or stereo would go haywire.
Jodrell Bank is a radio quiet zone, there's a big sign at the entrance saying "All mobile phones must be switched off." No please, it's not a request. A couple of years ago they were doing a big survey with the Lovell, and they discovered that the power leads for all the desktops were at a resonant frequency of the wavelength they were using. For two months everyone had to turn of their computers between 10am and 4pm!
How's China working out?
It has a stable government, a strong stable currency, the fastest growing economy in the world...
Oh sorry, I see what you mean.
I've been meaning to post an update at the JREF, but I've been rather busy. I'm going to a conference in Chengdu the week after next where I'm supposed to be giving a talk, I'm in the middle of writing a paper, I'm supervising somebody else's data reduction, and since there's a holiday on Monday and Tuesday next week I haven't had much time to do it.
I promise I will soon though!
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