Silent Lighting

DanOnKeys · Post by **DanOnKeys** » Thu Jun 12, 2003 4:23 pm

I don't understand why LEDs aren't more popular for this purpose. They're not a fragile as the cold cathodes, are much easier to place, and much cheaper. I'd just setup a bunch in different parts of your case (you could eliminate all shadows) -- or maybe just set them up in clusters. There's also "LazerLEDs" available: three bright LEDs pointing at slightly different angles with a standard 4-pin pass-through power connector -- not as cheap as doing it yourself.

lenny · Post by **lenny** » Thu Jun 12, 2003 9:31 pm

Radeonman wrote:I have a window on my case.

I've always wondered if the window (acrylic?) dampens fan / drive noise as well as steel (or aluminum). Or if there's any perceptible difference. One thing for sure though - you're not going to be able to foam that panel.

Radeonman wrote:I am interested in Cold Cathode lights, but am wary of something that needs an inverter.

I'm not sure why you're wary of the inverter. It does have high voltage (approx. 600V) at very low current.

I've played around with the 12" kit from SVC, and it seems OK. Total power drawn for one white 12" tube is approx 2.4W (200mA @ 12V). It draws about twice of that with two tubes (the inverter has dual outputs). I did not notice any noise from it, but I wasn't specifically listening for any either. The inverter does feel warm, but total heat generated cannot exceed 2.4W.

Incidentally I've come across an article somewhere that asserts that LEDs are actually only about as efficient as an incandescent bulb, but the light output is all directed in one direction making it appear brighter. This seems hard to believe for me, but I have no facts to either prove or disprove it. Thought I'll just throw it here and see what the folks think.

Zhentar · Post by **Zhentar** » Fri Jun 13, 2003 12:25 pm

I think that article was wrong; a few years ago (6 I think, can't beleive I remember something so old) I read an article about how LED traffic lights were several times more efficient than incandescent lights, though they cost quite a bit more. Now just about every traffic light in this city is LED so I'd assume the article I read was right..... I think you can find more on Dan's Data about efficiency of different lights.

lenny · Post by **lenny** » Fri Jun 13, 2003 1:37 pm

This is getting seriously off-topic, I won't post any more after this. I got curious enough to google for it. I found something here. Summary: as of 2001, LEDs are not much more efficient compared to incandescents in terms of lumens per watts. They do talk about why they are better at some applications (including traffic lights and flashlights).

There's quite a lot of discussion in one of the sci newsgroups, but I didn't try to follow it.

They've also changed just about all the lights where I live, and there was an article in the papers a couple of years ago talking about how much less electricity the city uses because of the LED traffic lights.

Anyway, I'll try to test out the cold cathode this weekend to see if there's any buzz or hum. I'll test it with a stand-alone power supply so there's no other noise from the PC. That will bring this thread back on topic

ccorayer · Post by **ccorayer** » Sat Jun 14, 2003 8:58 pm

Still massively off topic.... But possibly of some use in the near future.

There is currently in development a 5 watt white LED. This is of interest for many reasons. A company called SureFire is evaluating this for possible use in their flashlights. They are hoping for light in the 80-100 lumen range at 9 volts. Whether this comes to pass is anyone's guess.

Still, I could EASILY see one or two of these LEDs lighting the entire case, and most of a room, and the room down the hall....

Gandalf · Post by **Gandalf** » Sun Jun 15, 2003 6:41 am

LED's can *easily* illuminate an entire room. They illuminate my room anyway. I have three LED spots rated 2W each. They're supposedly 90candela each and deliver 35Lux (at 1metre). I (obviously!) have a 24v ac/dc adaptor for it. I wouldn't want to fry them with 230v

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Gandalf · Post by **Gandalf** » Mon Jun 16, 2003 2:29 am

I'm afraid I don't have a webcam or anything of the sort.
You can however find more details on the LED-lighting here:
http://www.alenco.nl/showroom/LEDverlichting.php3
Though I'm afraid the site is in Dutch

.

I have 3 MR16 LED (check the site) lights. One hovers above my monitor and pretty much shines down on my head. One is mounted at my room door and the third one is somewhere between the other two

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lenny · Post by **lenny** » Thu Jun 19, 2003 10:54 pm

Here's my test results promised earlier.

Summary : I couldn't tell if the lights were on or off, with my ear less than an inch from the inverter.

This is with a sample size of 1 CCFL kit, from 1 vendor. YMMV, etc.

Actually I was contemplating using the CCFL for room lighting. For less than 5W (two 12" tubes), it does a darn good job too. The box says 29,000 cd/m^2 per tube, but I have no way of telling how accurate it is. It definitely needs reflectors and diffusers (or reflectors alone for indirect lighting) to be useful though, since the light emits from a long thin line.

aphonos · Post by **aphonos** » Thu Jun 19, 2003 11:19 pm

lenny wrote:Here's my test results promised earlier.

Summary : I couldn't tell if the lights were on or off, with my ear less than an inch from the inverter.

Try turning your head and opening your eyes.

Lights are hard to see with your ears.

Sorry, couldn't resist

Siili · Post by **Siili** » Fri Jun 20, 2003 1:58 am

Read this old article yesterday on a finnish site. Nice pictures on differently coloured cold cathode lights + a window kit installation.
http://www.muropaketti.com/artikkelit/k ... ndex.phtml
Too bad my computer is under the table, on my left side, so window wouldn't really show anywhere. And would have to remove the Acoustipack on the window area too. Maybe some day when my computer is situated differently.

Silent Lighting

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