Silencing a floresent light...

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jhh
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Silencing a floresent light...

Post by jhh » Sat May 24, 2003 11:57 pm

...ok, so not to do with PCs directly, but my pc is directly under one and it's driving me crazy!

I'm getting a very quiet, very high pitched whine coming from it, a little like an old whistling kettle boiling two floors above. What can I do???

I don't own this flat so I can't make any serious changes, and I've tried desk lamps but they don't seem to be bright enough at night + give too many shadows. I'm also skint so no expensive solutions please!!

Mr_Smartepants
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Post by Mr_Smartepants » Sun May 25, 2003 12:17 am

Fluorescent lights buzz when their igniter circuit starts wearing out. You could just try replacing the 'bulb' with a new one. There's also a small isolation transformer wired in there that might be inducing coil whine. You could try wrapping the transformer in low-density foam to try to quiet it.
Last edited by Mr_Smartepants on Tue May 27, 2003 1:53 pm, edited 1 time in total.

LushMD
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Post by LushMD » Sun May 25, 2003 12:31 am

If you can locate one, you might consider a halogen lamp (they are becoming increasingly scarce in the US, at least at the stores near me; apparently some consider them to be a fire hazard :wink:). In any case, halogen lamps are very bright (then again, I use 300-350 watt bulbs; I used to use 500W bulbs, but I can't find them anymore), silent (at least as far as I can tell), and fairly inexpensive ($20 for a floor lamp w/bulb). Take care.

PS I know what you mean about fluorescent bulbs though...that's why I keep my kitchen light off as much as possible.

jhh
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Post by jhh » Sun May 25, 2003 3:48 am

coil whine sounds about right for the noise, where in the assembly wil I find the transformer?

LushMD:
300-350 watts?? 500?? are you trying to emulate perpetual daylight?

LushMD
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Post by LushMD » Sun May 25, 2003 6:34 am

jhh wrote: LushMD:
300-350 watts?? 500?? are you trying to emulate perpetual daylight?
Something like that :wink:). Actually, the bright light makes it easier for me to focus on my studies (less than a month until the boards...hope at least one of my lamps lasts until then...). Take care.

jhh
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Post by jhh » Sun May 25, 2003 6:50 am

what are the 'boards'? sounds strange!

btw, I almost take it as a compliment that I CAN hear the lights - shows off how quiet my pc is!

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Re: Silencing a floresent light...

Post by powergyoza » Sun May 25, 2003 12:43 pm

Your best option may have to be not to use the ceiling fluorescent at all... and use a bright task lamp instead. Or move the computer to a different part of the room.

High wattage halogens are said to be a fire hazard. I'd stay away from them. I've heard as high as 1000 degrees (F/C?) versus 130 for fluorescents at the same lumen output. A 55 watt fluorescent throws out the same amount of light as a 300 watt halogen.
jhh wrote:...ok, so not to do with PCs directly, but my pc is directly under one and it's driving me crazy!

I'm getting a very quiet, very high pitched whine coming from it, a little like an old whistling kettle boiling two floors above. What can I do???

I don't own this flat so I can't make any serious changes, and I've tried desk lamps but they don't seem to be bright enough at night + give too many shadows. I'm also skint so no expensive solutions please!!

Zhentar
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Post by Zhentar » Sun May 25, 2003 12:47 pm

I suggest you use my method- if your monitor doesn't provide enough light, you shouldn't be doing it! :)

of course my monitor whines but I can't afford to get a new monitor.... fortunately it usually stops after a while.

jhh
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Post by jhh » Sun May 25, 2003 12:56 pm

Quite the oposite, the problem is that my monitor produces too much light to be used in a dark room for any length of time, but with TFTs if you turn the brightness down you loose all the dark gray shades to black - hardly ideal for the odd game of quake/tenebrae

Gandalf
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Post by Gandalf » Mon May 26, 2003 12:34 pm

Ditch all convetional lights and buy LED based spots :). There's a decent solution! No heat, no noise, low power consumption, fair amount of light, last a loooooooooong time.

SpyderCat
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Post by SpyderCat » Mon May 26, 2003 1:24 pm

Gandalf wrote:Ditch all convetional lights and buy LED based spots :). There's a decent solution! No heat, no noise, low power consumption, fair amount of light, last a loooooooooong time.
edcrane wrote:After quieting my HDs to a hush I noticed a strange ticking noise. I thought it might be a fan so I stopped each fan in my case (individually) to no avail. Finally I noticed it seemed to coincide with my secondary NIC's activity light which is constantly going on and off. Is it possible that this is actually the LED? or is it likely to be something else on the nic? I don't want to disconnect everything and unsolder it just to find out that LEDs can't make noise-
Still sure LED don't produce noise ? :lol:

jhh
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Post by jhh » Mon May 26, 2003 1:43 pm

Wish I could replace the lights, but I'm not sure the landlady would understand my silenco fetish!

I've just lolved this problem, so I'll give how in case anyone in future searches the forums for a similar problem (we can hope)

I noticed that when I touch the tube the noise stops the noise, and takes a few seconds for it to become audiable when I let go - so I guessed that the tub itself was vibrating and causing the noise.

How to stop it? by increasing the weight of the tube I can change it's resonance, these things are light so two thin strips of acustic foam wrapped around the circumferance was enough!

The diferance was imediate and total! :) At last I can hear my PSU fan again! So long as the foam doesn't start melting I think I've got it sussed.

jhh
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Post by jhh » Mon May 26, 2003 1:49 pm

btw, my science may be wrong, any alternative expalanations an why this works are welcome, but the fact is that it does work very well, even with my ear right up to it I can hardly hear a thing!

Katana Man
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Post by Katana Man » Mon May 26, 2003 4:37 pm

Well, my florescent lights all humm loudly. I tried your technique with holding the lights, and it did not change.

I did notice something interesting at Lowes the other day. I saw some florecent lights that were claiming something like 50% (might have even been higher) quieter than other florescent lights. I didn't have time to check them out fully, and I intend on going back to look into it. I have many florescent lights and replacing with task lamps is not an option. I need a quieter drop ceiling lighting. I hope those new Lowes lights are the trick. I'm not sure if it was a new bulb, or the whole light housing is needed as well. I'm assuming it will be the whole housing. This appears to be where my humm comes from.

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Folks, it's spelled "fluorescent" ;-)

Post by NeilBlanchard » Mon May 26, 2003 4:55 pm

Hello:

The starter and/or ballast is the most common cause of fluorescent lights making noise. Since they actually flash at the same frequency as the AC mains does, it is easy for them to hum. And replacing the ballast is not all that easy -- most likely you'll need an electrician to do it.

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Post by Gandalf » Tue May 27, 2003 9:04 am

SpyderCat wrote:
Gandalf wrote:Ditch all convetional lights and buy LED based spots :). There's a decent solution! No heat, no noise, low power consumption, fair amount of light, last a loooooooooong time.
edcrane wrote:After quieting my HDs to a hush I noticed a strange ticking noise. I thought it might be a fan so I stopped each fan in my case (individually) to no avail. Finally I noticed it seemed to coincide with my secondary NIC's activity light which is constantly going on and off. Is it possible that this is actually the LED? or is it likely to be something else on the nic? I don't want to disconnect everything and unsolder it just to find out that LEDs can't make noise-
Still sure LED don't produce noise ? :lol:
100%.
If a LED produces noise then it's not a LED but a SED (sound emitting diode hehe ;) ). :P. But yeah, I'm fairly sure of it. Unless of course something is really wrong with the LED.

edcrane
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Post by edcrane » Tue May 27, 2003 9:14 am

as far as balancing light to prevent eyestrain, I read an article in an AV forum a while back the suggested running a low brightness light behind your TV (should be applicable to monitor as well) to make sure that your eyes don't get murdered with high contrast transitions and such. I don't have room for that myself, but the effect is also achievable using a flexiable desk lamp and aiming it at the cieling or wall. The important thing is that you don't want a lot of light to be hitting the front of the monitor/tv generating glare, and you want the light to disspipate so it's not just one distracting point of light.

In my case, I used a small desk lamp (as described) with a relatively high quality flexable neck. I installed a 20watt blub (rated at 180 lumens) and keep the thing running pretty much all the time I use the room. It makes everything very comfortable, reducing eye strain without the cost of distracting bright lamps or all encomposing flourescent lights.

Highly recommended room-mod. ;)

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Post by wussboy » Tue May 27, 2003 11:42 am

Yeah, I've heard and seen that as well. It seems to work pretty effectively.

halcyon
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Post by halcyon » Tue May 27, 2003 11:58 am

Neil is right. The most common source in fluorescent lighting buzz is the ballast. If you want to test if it's the starter, you can remove it after you've turned the lamp on (don't do this, unless you know what you are doing though! I'd rather not see any of you get electrocuted). If the buzz remains after the removal of the starter, then it's the ballast. In my opinion, it's almost always the ballast and not the starter.

The ballast that make sound are usually magnetic rather than electronic. Electronic ballasts can shift the switching frequency to beyong 20 kHz and they are inaudible. They also get rid of most of the light flicker (I'm very susceptible to this myself).

Ballasts are usually difficult to replace (unless you're an electrician) and I wouldn't recommend it. A good grade ballast is not necessarily cheap either. These are usually graded by their sound levels to three classes. The A rating is the most silent.

Hope that helps.

regards,
Halcyon

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Post by Vikroda » Tue May 27, 2003 11:46 pm

I think I paid more for the ballast (~$15) than the drop down fixture and the high CRI (color rendition index) tubes I bought at Home Depot. I bought the electronic ballasts because the magnetic ballasts were causing an unacceptable flicker and not because of the sound as this was in my garage. There's a hum with one set of lights but not on the other.
Home Depot didn't carry fixtures with electronic ballasts for the standard diameter tubes. However, some of the fixtures for the thinner tubes did have electronic ballasts (~$40?). I think the thinner tubes are more expensive but are supposed to be more energy efficient.

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Post by Katana Man » Wed May 28, 2003 5:32 am

Is the balast inside the light housing? In otherwords, I could just purchase new light housing with bulbs and replace them all?

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Post by Tungstengruvsten » Wed May 28, 2003 8:19 am

ok-here's the deal. Older flourescents had a separate transformer and starter(basically a neon light)

Over the years these became incorporated into a 'ballast' Inside the ballast is the transformer and starter.

So if you have a starter(little round thing with two terminals on one end) that you can change, you won't have a ballast, you will have a transformer elsewhere. The ballasts are usually heavy black things about 2"x2"x10" and they are very easy to change. Just follow the wires. BUTTT it's usually cheaper to buy an entire fixture than just a ballast.

ALSO-All tubes load the ballast differently-older ones can cause starters to work improperly or create noise and hum due to loading. SO it would probalby be worth your while to try out a different bulb or two before switching the guts out.....

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Post by Katana Man » Wed May 28, 2003 8:26 am

Great, thanks for the info!

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