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View Full Version : Dimmable Fluorescents with electgronic ballasts



az
9th January 2007, 07:08
I just installed some indirect lighting in my parents' kitchen and thought I'd share some of the knowledge I've gained from this, since I certainly didn't know such a thing as dimmable fluorescent tube existed.

So we all know fluorescent tubes. They provide a lot of light and draw relatively low power, their light has an awful color (and color rendition), they flicker, they don't come on instantly, sometimes the ballast hums. I thought so, too. But actually modern fluorescent tubes come in nice warm white tones with quite good color rendition (Just don't get the cheapest ones). There are electronic ballasts which remove the flicker, make the tubes come on almost instantly, lengthen their life by 10%, cut power draw by 10% while providing the same light output, don't hum, just switch the tubes off when they fail (so no flickering and trying to come on all the time), and there are even dimmable ones.

Some of these are controlled via installation buses, which was of no interest to me, but others are controlled via 1-10V control (almost like the 0-10V lighting control for stage lights etc.). They provide a low current 10V voltage. If the full 10V get fed back to them, they dim the lamps to their lowest level, if none-1V is fed back to them, the lamps are fully lit (so if you just leave the dimmer controls unconnected, the lamps will work at 100%). Controlling this couldn't be easier: Just put a 100k log potentiometer (connect the left and middle (wiper) pin of the pot together) between dimmer out and in, and you're done.

I wouldn't have thought it to be this easy, and you can find electronic ballasts for cheap on ebay (though dimmable ones not so much). My parents now have nice, cosy and yet bright and glare-free light in their kitchen. Nice surprise for when they return from their vacation tonight :)

Dr Mordrid
9th January 2007, 10:44
My studio & keying lights are Kino-Flo photo-flourescents with anti-flicker/dimming ballasts. Definitely the way to go, but 4' bulbs run $22 - $48 each :p

Kino-Flo site.... (http://www.kinoflo.com/index.htm)

az
9th January 2007, 11:06
You can get full-spectrum T8 fluos for much less from aquarium dealers etc. You won't have the added "hi-tech" price inflation (like audiophiles or tech geeks of all fashions like to pay...)

Paddy
9th January 2007, 11:30
:up: I use dimmable T5 tubes for my marine tank

VJ
10th January 2007, 05:26
All tube lights in the auditoria of our university are dimmable. This allows one to dim the lights to make a projection easier to read.
In one auditorium there are multiple circuits that can be switched on/off, to allow shut off the lights closer to the projector. There also is one auditorium where the dimmer is by means of buttons, and where there are a number of preset buttons (dim to 25%, 50%, 75%) next to the buttons to dim manually.


Jörg

Dr Mordrid
10th January 2007, 10:17
You can get full-spectrum T8 fluos for much less from aquarium dealers etc. You won't have the added "hi-tech" price inflation (like audiophiles or tech geeks of all fashions like to pay...)
It's not all tech inflation, it's the spectrum especially with the blue, red and green keying lights.

Greebe
10th January 2007, 10:41
Think he's refering to the dealers of such items normally charge an arm and a leg because they specialize in those products Doc. Sadly here in the US even pet stores charge way too much for such things.

Kinda like the 12v 20w quartz halogen bulb for my desk light I got a few days ago @ Home Depot. $7ea+tax for the bloody thing when you can get a desklight with the same for $14. Excessive pricing for such a nominal thing that is mass produced by the millions.

gt40
10th January 2007, 12:47
Think he's refering to the dealers of such items normally charge an arm and a leg because they specialize in those products Doc. Sadly here in the US even pet stores charge way too much for such things.

Kinda like the 12v 20w quartz halogen bulb for my desk light I got a few days ago @ Home Depot. $7ea+tax for the bloody thing when you can get a desklight with the same for $14. Excessive pricing for such a nominal thing that is mass produced by the millions.

Kinda like batteries.
A 2032 3V battery will cost here between $3-$5 from a retailer like Radio Shack with all the fancy packaging.
Or I can buy them for about $0.35 from Digikey :rolleyes:

Tjalfe
10th January 2007, 13:17
or perhaps Cables from e.g. bestbuy/futureshop versus online:_ogre: