Compact fluorescent backlight

parksgm · 07-10-2006, 12:23 PM

Hi all,

I'm building a compact fluorescent backlight upgrade (not CCFLs!) for my 7" Super screen using bulbs like these:

http://genet.gelighting.com/LightPro...ouble+Biax®_T4

...except with a color temperature of 5000K. They'll be arranged in horizontal rows behind the LCD. Heat will be managed through a combination of case design and forced air cooling.

I've searched for a similar project on the forums in an attempt to determine the overall feasability/any potential drawbacks, but all other backlight upgrade threads seem to revolve around using either CCFLs or LCDs. Anyone know of an attempted compact fluorescent light upgrade?

Pics to follow...

Fusion-One · 07-10-2006, 01:58 PM

I tried it. I used 6 850lumen (13w) compact fluros. It got too hot, even with a 120mm fan blowing into the lightbox.

parksgm · 07-10-2006, 06:44 PM

1) Aside from the cooling issue, did it effectively light the screen?

2) What exactly do you mean by "too hot". Did it damage your LCD?

Thanks,

Gregory

Fusion-One · 07-10-2006, 08:39 PM

It was bright, I'd say about twice as bright as the normal backlight. By too hot I mean that the box was so hot i couldn't comfortably hold my hand on it.

turbocad6 · 07-10-2006, 09:14 PM

floresent lamps are way to inefficent, & will make a whole lot more heat than the same amount of light from ccfl's.. why not use ccfl's, there not very expensive really or hard to get.... the side benifit of being able to dim them will be another huge plus... I don't get why you'd rather use the wrong thing for the aplication when the right thing isn't any harder really?

miztahsparklez · 07-10-2006, 11:12 PM

5000k is more of a bluish white isnt it?

Sidewalksalvage · 07-10-2006, 11:19 PM

I think the CCFL is a better way to go. They are much more available and manage temperature much better.

Fusion-One · 07-10-2006, 11:21 PM

Go with CCFL, or LED's. Those're the best options.. and neither is very expensive.

miztahsparklez · 07-10-2006, 11:26 PM

arent LEDS directional though? so wouldnt you get "spotting" unlike an even glow with a ccfl tube?

Fusion-One · 07-10-2006, 11:28 PM

Short answer: No.

parksgm · 07-10-2006, 11:52 PM

No reason to argue the heat or efficiency issues...CCFLs definitely produce less heat and are more efficient...but they are not locally or readily available. In addition, I'd like to get some idea of the amount of illumination I'm going to need to make the screen sunlight readable, and before I order and ship non-returnable CCFLs, I thought that I'd experiment with my $12 for four 13 watt CFLs that are locally returnable.

From what I've read, there is an issue with getting multiple CCFLs running with inverters, and I'm also hesitant to place a CCFL order over the internet for component parts that I can't return if they don't work. Can anyone recommend a source they've used?

parksgm · 07-10-2006, 11:54 PM

Quote: Originally Posted by miztahsparklez

5000k is more of a bluish white isnt it?

According to a couple of sources I've seen (one here, and one elsewhere online) 5000-6000K was the color temperature to shoot for that provides the best color rendition. If anyone has any experience otherwise, please, let me know.

turbocad6 · 07-11-2006, 12:01 AM

dude, sometimes it takes dissasembling of equiptment that cost big bucks, risking damaging, & sometimes it takes taking the plunge & ordering something that may or may not work.... getting something that won't work just cause it's cheap & returnable sounds like a big waste of time to me, but that's just my opinion

ccfl's are cheap & readily available..... sure it'll take a little more research & figuring out.... but in the end you'll be increasing your chances of sucess big time...

turbocad6 · 07-11-2006, 12:03 AM

a good source is mouser... I put a link in the multiple ccfl thread...

miztahsparklez · 07-11-2006, 12:05 AM

hmm maybe it doesnt apply here. but i was under the impression that 5000 was a bluish white, 6000k was a deep blue/purplish white. and somewhere around 4000-4500k was like sunlight white. i suppose a bluish white is better than a yellowish white. but supposedly the light wavelengths in teh 4000k areas provide better usable light.

well, dont mind me, i was just taking my general understanding of lights and trying to apply them to here. but i could be totally off in the monitor world.

i actually prefer a really bright screen, and tend to use the higher color settings on my CRT if that compares to this better, to provide me with that really bright white.

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