Will this light up a flourescent tube?

zmoz

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I have a bunch of those compact flourescent bulbs that screw into a regular light socket. (the kind with the spiral shaped tube) Right now I have one in a lantern thing that I made...but the problem is to use it I have to plug it into a power inverter to bring the voltage up to 115v AC. Can anyone tell me if I can get one of these: http://www.allelectronics.com/cgi-bin/category.cgi?category=290&item=INV-7&type=store
and use it to light up one of the tubes from the bulb? Will that little inverter light up something like that?
 

Steelwolf

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"This little PC board can power relatively large fluorescent lamps and many other 115 Volt lamps. This inverter will work fine on 4.8 Volts but draws a lot of current no matter what voltage. "

That quote was probably what made zmoz ask. Doug O, what made you say that it won't work? Is it because the board can't handle the power requirements? So would it work if we ran the tiny 4W tubes?
 

zmoz

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Actually, I didn't see that before...but I find it interesting... /ubbthreads/images/graemlins/smile.gif
 

snakebite

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i tried a regular tube on a ccfl inverter and got a dim glow.i have a ballast that runs from 24v dc though.
might be overkill for your setup.
pm me if you need some.
 

php_44

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I know this doesn't help with the parts you have on hand right now - but it is not hard to find compact fluorescent standard base bulbs that are designed to work from 12V.

A quick search for an example with specifications led to this link - Sample 12V CCFL. Looks like you can get a "7W" lamp that runs on 12V at around 600mA (which probably means it's not being driven to full capacity, since the built in inverter is probably not 100% efficient). The life is quoted at around 6000 hours. This would make a nice lantern. There's a lot of alternative energy dealers selling 12V lighting stuff, and it could be a great resource for your project.
 

Doug Owen

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[ QUOTE ]
Steelwolf said:
That quote was probably what made zmoz ask. Doug O, what made you say that it won't work? Is it because the board can't handle the power requirements? So would it work if we ran the tiny 4W tubes?

[/ QUOTE ]

That's a part of it, nowhere near enough power for the job. The voltage is all wrong (too high), current too low, frequency too high.

The driver is high voltage, high frequency, very low current and 'soft' (that is it has high source impedance so the voltage drops as current is drawn, prevening runaway). MOre over, you don't even have access to the tube leads, all you have is the input to the CFL driver circuit (which is expecting 120 Volts from a stiff source at 60 Hz), right?

Aside from this, you have a chance......

"No way" about sums it up to me.

Loose 4 Watt tubes would at most glow or flicker, you'll never get the tube up to working temperature with the less than one watt this unit is going to give you.

Best to use it for what it's designed for. If you need a ten or fifteen watt driver, get or build one.

An AAA cell will light your Arc, but not your car headlight nor will it crank the car.

Doug Owen

Doug Owen
 

James S

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I actually have that exact inverter. It's for CCFL tubes and not regular florescents. I bought it to light a CCFL tube where I didn't have the 9-12v necessary for the inverter it came with.

That particular board uses a lot of power and puts out a lot of power. At the rated 5v it will overheat the small CCFL tube I've got, but it works quite nicely at even lower voltages than it's rated. A great thing to have to experiment with for only $4!.

If i can find it amongst the as yet unsorted boxes of electronics stuff around here I'll go ahead and give it a try. However Doug is correct when he says that the output just won't be enough to make it light to any brightness. It may very well get it to glow a bit, but it doesn't have the power to warm the bulb up for the reasons he mentions.

They also have some 4 and 6 inch CCFL tubes at allelectronics and it will light those just fine and quite brightly. So if you're going to order that, spend an extra $6 or so and get a tube that it will work with /ubbthreads/images/graemlins/smile.gif
 

LED_ASAP

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The biggest problem is that those spiral flourescent bulbs have a inductive ballast built-in. You have to use 120V/60Hz to work with the ballast. The 100KHz-level power provided by those inverters will simply not pass the ballast, needless to say lighting the spirals. Unless you want to try sawing out the base and get direct access to the leads from the tube itself, it will be well off just to buy those regular CCFL tubes.
 

James S

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Oh, hmm, I was assuming that you had the tube separate from the ballast already. Hooking the inverter directly to the ballast is unlikely to do anything but make the inverter warm /ubbthreads/images/graemlins/wink.gif
 

zmoz

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Yes, I already have some of the tubes removed from the balast. Seems that the tubes are rated at about 10,000 hours but the balast only lasts for about 100 starts... /ubbthreads/images/graemlins/rolleyes.gif
 

star882

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"The biggest problem is that those spiral flourescent bulbs have a inductive ballast built-in."
All the new ones use tiny switching power supplies.
 

billw

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It will work to light a bare tube, although not at full brightness,
of course. Here are some pictures of a similar
inverter driving a nominal 27W CFL (not twisty, but otherwise
presumably the same), while drawing about 0.5A at 6V. (3W!)
It's brighter than I expected (brighter than the same
inverter driving a 4W normal "tube", for instance.) Not
nearly as "bright" as when driving a small CCFL, though
(I will not hazzard to guess about total lumens...)

http://www.geocities.com/westfw/electronics/fluor-1.jpg
http://www.geocities.com/westfw/electronics/fluor-2.jpg

As I understand it, a fluorescent ballast or inverter is
sort of like a LED driver, in that the ballast contains any
current limitting that is needed. So a 3W ballast will drop
3W into whatever tube you connect it to, and whether that
actually results in light is up to the tube. (also, whether
the tube will get damaged, etc.) CCFL inverters tend to be
a bit more finely tuned to the tune they're connected to, as
you can watch the current consumption change quite a bit
depending on what tube you connect, but I've gotten light
out of quite a variety of tubes to emit SOME light. (4W
straight tubes, xxW circular bulbs, and the CFL pictured,
not to mention a variety of the sorts of CCFLs they're supposed
to work with.)

The inverter's failure point seems to be the insulation of
the secondary transformer winding. Turn up in input voltage
too far, and you start to get arcing and burnt insulation.
The attempt at a micro-sized jacob's ladder was not successfull,
though I eventually did enough damage to the inverter that it
would no longer light up anything...

Enjoy
BillW
 
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