Lightbulb and Hi-fi question!

stereo_steve

This might sound like a very odd question to ask! But as I was running out of the house this morning, I was looking for my keys. I went into my room and turned on the light. Not the ordinary flicky on and off switch but a dimmer switch. At the moment, the light isn't working properly and it goes dim and bright repeatedly. Anyway at the same the light went on the hi-fi started making hissing noises! I tracked the problem to a wire I have connected to my mic slot in the hi-fi.

The question is, how is the hi-fi picking up interference from the light? Or is it coming from the switch? They are both about 2m away from the hi-fi. the only thing that I can think of that comes from light is photons. But I think I'm way track guessing whats causing it!

Also by the way, I held a piece of card in front of the wire but it still pick up the signal! Its driving me nuts!

Saruman

Photons are not the only thing.. there is heat and there is also sound.. probably a lot more stuff too.. anyway i think the sound could be what the stereo is picking up.. especially if you have something connected to the Mic... could be wrong but its plausable.

stereo_steve

Theres no mic connected! I just have a wire I leave in the slot for when I connect it to my mp3 player.

Victor

Dimmer switches use two circuits, one via the light and the other via a resistor (hence some of them hum at low brightness). As you adjust the brightness of the light, you are actually changing the current balance between the 2 circuits. While most of the resistance is given off in heat presumably some is in electro-magnetic waves that are picked up by the speakers / hi-fi. Some speakers will also hiss as they discharge any residual charge when they are turned off.

However, given that you say the dimmer is mis-functioning, I suspect it is shorting out. I would also check to make sure the light and the hi-fi aren't on the same house circuit (they shouldn't be - check this by removing fuses at the fuse board). I suggest you get an electrician to check out the house and dimmer wiring.

amen

hmm most dimmer switchs no longer use resistors. Nearly all use Triacs. Basically these restrice the current available at any particular point in time.

As for your noise you probally have a wiring problem although as the triac acts as a fast switch your speakers/mic could just be picking up the em field generated by the dimmer.

same way a speaker makes noise if you place a mobile beside it and receive a call

Saruman

Stupid question time (gotta love em).. what funciont of your stereo are you using? Is it by any chance the radio? in which case nuff said on the matter!

stereo_steve

Thanks! Its not on the same circuit. The upstairs lighting is all on the same circuit! I supose its about time for a new switch! I only got it a few months ago!

Stupid question time (gotta love em).. what funciont of your stereo are you using? Is it by any chance the radio? in which case nuff said on the matter!

Very funny! no it was on VIDEO!

Saruman

since its dodgy anyway i think its best yeah.. new switch.. haha screwed if it does not work though.. you can call one of thos paranormal programs and say your stereo is posessed by the ghost of someone electrocuted on your dodgy switch!

EvilGeorge

An old priest and a young priest is in order.

Normally get a flick from my light when I plug something in to a socket about 3/4 of a meter below.
Waiting for it to blow but hasn't in the last 10 years.