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CCFL: Cold Cathode

Posted: 18 Apr 2006, 11:43
by lbyford
Hi all

For any one who is interested I have installed two CCFL lamps in my van. Each of these these appear to me to be about the same brightness as 2 x 8w Flourescent tubes. By my reckoning they use about 1/3 of the power. (the PSU was 400ma for the CCFL).

These lamps are used by car modders and PC modders so are widely available on fleabay. They are all 12v and can be many different colours. You can also get from DIY stores (mine were from Focus) as they are used as kitchen display lighting (it seems) this type are retail packaged and come with a 12v/240v transformer which is not needed. My lamps were £14 ea

Seach on ebay for CCFL or Focus ones are:
http://www.focusdiy.co.uk/invt/43879

jm2pw

Lee.

Posted: 18 Apr 2006, 13:49
by Hacksawbob
wiki'd

Posted: 18 Apr 2006, 18:16
by Ray
Thanks for the info, I have been looking at led lighting but seem to be more expensive. I'll give these a go I think.

Posted: 18 Apr 2006, 19:28
by Dan Wood
To be pedantic, the fluorescent lights i've ever seen in campers are all cold-cathode types.

Suddenly, the phrase 'cold-cathode' has been seized on (by PC modders I think!) and so they are starting to appear as a 'new' idea!

The tubes are thinner, and the driving electronics a little fancier, but the basic technolgy is the same.

Does anyone have a 12V fluorescent lamp that isn't cold cathode? You can tell by counting the wires at each end of the tube. Althought there are two pins on the 'old style' tubes, there is usually only one wire connected in the fitting.

One wire at each end = cold cathode

Posted: 19 Apr 2006, 12:48
by djsalt
hi, i'll try and explain ccfl's :
... to cut a long desciption short http://www.answers.com/topic/fluorescent-lamp
on a small fluorescent tube (the ones we know as ccfl's) it takes a small amount of voltage to start the arc required to get the tube lit. The invertor is always required because due to the nature of fluorescent tubes without it a tube to destroy itself. Once arc'd the tube tryes to demand and increasing amount of current.. thus destoying itslef when the current draw increases to mcuh (doesnt take long!) | the invertor limits the current draw.

A large tube requires a larger voltage to start .. thousands and thousands of volts. The reason most big tubes blink when starting is because they arent provided with enough voltage to correctly arc first time. There are a number of methods that cause some tubes to 'instant on' but lets not go into that :)

-__ basically ccfl's are just fluorescent tubes __- just small

Posted: 20 Apr 2006, 11:53
by lbyford
To be pedantic, the fluorescent lights i've ever seen in campers are all cold-cathode types.

I'll go and stand in the corner. :oops:

:lol:

Posted: 20 Apr 2006, 12:38
by djsalt
To be pedantic, the fluorescent lights i've ever seen in campers are all cold-cathode types.
^^ you werent wrong though :idea: fluorescent tube lights are cold cathode :)