Need help finding an RGB LED panel light/bulb

[BruceM]

I did some experiments with an LED T8 tube light and have found that the warm white LEDs (yellowish phosphor blob over blue/UV LED) bother my epilepsy as badly as CFLs-  I guess it's the spiky light spectrum. 

I'm wondering if the white light generated by red, green, and blue LEDs might be more tolerable, but haven't had any luck in finding a panel, tube or bulb light to check out. 

Anyone know of a source for a non-phosphor, white via RGB LED light?

[Wizard]

BruceM,

You need to build a power supply that is supply pure DC for LED for no blink to drive these LED T8 tubes, might have to modify the circuit in the tube itself to work on DC, I have not found commercial version yet, my eye can see it easily that why I did not adopt xmas LED strings at ALL and my CRT monitors are all set at 85Hz. 

Fluorescent lighting devices flicker/blinks no matter you try, it's nature of it's AC at any frequencies is what kept it lit via arc action thru the tubes.  Hence this reason your epilepsy is setting off is caused by blink-blink even your brain can't tell it is.

The LED bulbs from philips does not flicker but not enough lumens (only 220 ish) and costly.

Cheers, Wizard

[BruceM]

Thanks Wizzard, I assumed the same thing before looking into these a bit further.

I've tried some phosphor-white LED lamps on straight (resistive current limiting) battery power-  same "feeling of flicker",  even though there is NO flicker involved.  

The T8 tube lamp uses series connected AC caps for current/voltage limiting, then full wave rectification straight to the LED series strings.  This is a common design for these.  It is pretty easy to convert to pure DC operation, and there are DC 12V units as well.  But the flicker rate of these on full wave rectified DC is 120Hz, just like incandescent bulbs. (Though depth of modulation is greater.)  Still, not many folks are bothered at 120Hz.

Same issue with the new electronic ballast fluorescent lamps-  only on these the lamp polarity switching rates are 50KHz and up. In the better units where the high voltage DC is regulated (the ones that would have no Lister Flicker) there is no low frequency modulation of light output.  What some people  perceive as flicker with these lamps really isn't - it's the odd spiky spectrum that makes some people's brains go wonky.

[Wizard]

Aha.  You can also modify the T8 to have cap across the bridge's output to smooth out pulses.

I have same issue,  but not the medical condition.  I do simply do not like spiky spectrum of white LEDs that you can buy.  More like empty white light or off color detectable.  What you need is warm white high quality white LEDs with triple RGB wide spectrum phosphors.  And might suggest 4 LEDs idea: (red, green, blue and yellow).  But the issue is have to adjust each of four color LEDs to get even white output.

PS: higher CRI, better the spectrum of lamp.  What you need is index of CRI 90 or above.  Average CRI of fluorescent stuff is between 60 to 82.  Above 90, special order stuff.

There are bulbs out there that is made for SAD sufferers.

Cheers, Wizard

[BruceM]

Yep, that's why I'm interesting in finding an RGB LED light for evaluation.  If I have to make my own panel light, I'd use a mix of LED colors (amber seems helpful in some experiments I've done with blue-white LEDs plus amber) in hope of filling in the light spectrum enough to make them comfortable.

The color mix for tube or panels can be adjusted by the ratio (numbers) of each type of LED, as well as current control for each type. 

Since the white LEDs have become more affordable and available in neutral or warm colors, the RGB LED products have disappeared.

I still hope someone will know of a source for an RGB type panel, tube or bulb light that I can get for evaluation.

[bschwartz]

Is this the type of thing you are looking for?
http://cgi.ebay.com/UltraBright-LED-DJ-STAGE-PARTY-Wash-Light-RGB-260p-10_W0QQitemZ290398460340QQcmdZViewItemQQptZAU_DJ_Gear_Lighting_Equipment?hash=item439d18d9b4#ht_9723wt_1024

[BruceM]

Yes, Bshwartz, that's the sort.  Thanks!  I'll have to write them and see if they have any lumen data. Apparently most people are unconcerned about the output level of a lighting product(!) Someone in the US must be selling it- seems unlikely to be made anywhere but in China, these days.

PS- Yep, lots of these, now that I know they are "wash" lights.  Thanks again, Bshwartz.

[Crofter]

I am following this with interest. My first experience with LED lighting was with a cheapy led flashlight and really found the light disturbing. I know that I dont have entirely normal spectrum response since I am red / green deficient but at night with this light I cannot seem to find sharp focus on anything ann my eye mechanism continues trying. I look forward to trying some of the new ones with corrected colors.

not a nighthawk!

[Wizard]

Crofter,

You are experiencing eye focusing issues with excessive blue light sources even is hidden in white light.  I also have same problem with these especially blue LEDs stuff and some white LEDs.

Blue spectrum is hardest to focus and is true in projection TVs.  I always see one blue CRT more closer than other red and green CRTs and is more blurry even with best focusing efforts.

Cheers, Wizard