powering CCFLs

[chico]

hello I was wondering how I could test my CCFLs in my broken computer monitor.
I know that there are computer kits to power CCFLs and I can buy inverters off of digikey, but wouldnt every CCFL have different voltage and current requirements?
or are the CCFL kits and inverters smart?
perhaps CCFLs have a large operating range?

how does this work? I know people use 1 tester on many different CCFLs.

 

[Sceadwian]

CCFL's don't really have voltage/current requirements as such, they have power requirements although the voltage does need to be high enough to start the bulb this is pretty generic for most bulb types. and not excessively critical. What you use would depends on the wattage of the bulbs you're testing, not sure what wattage to suggest for monitor tubes, but basically any low wattage driver will be able to at least test basic functionality of higher wattage bulbs.

 

[debe]

This is what i use, its a savaged powersuply from a broken monitor & runs of a 12V plug pack. Use it for testing CCFL tubes.

 

[chico]

CCFL's don't really have voltage/current requirements as such, they have power requirements although the voltage does need to be high enough to start the bulb this is pretty generic for most bulb types. and not excessively critical. What you use would depends on the wattage of the bulbs you're testing, not sure what wattage to suggest for monitor tubes, but basically any low wattage driver will be able to at least test basic functionality of higher wattage bulbs.

Hmm but to strike (aka start) the CCFL i need to have a high voltage, up to 2KV for these small CCFLs on digikey (here).
If i had a little inverter would I be able to even cause these to turn on? or will they just be dim? If i had an inverter that had too high of a voltage would it break the CCFL or just act as a current source?

 

[Sceadwian]

Your Digikey link is malformed, it goes to the search page not results, but don't worry about it as your question is more general than you might think.

Just to give you an idea, I just scraped a common LCD monitor that had two CFL drivers that drove two tubes each. The output caps were rated at 3kv. I have no way to measure voltage that high but I would say that it would easily strike a 2kv tube.

Excessive strike voltage again isn't technically an issue, it's total energy in the strike that can kill a tube. I have four full sized tubes in my basement that all have black ends from old school bad fluorescent drivers (magnetic ballast with capacitor starters bypassed by arc tubes), they start up right away because of the high strike voltage, but the strike energy is too high so electrode vaporization kills the tube, this is why there's a urban myth about turning tube lights on and off causing great power usage than leaving them on all the time, which is not the case, excessive power cycling however will shorten tube life compared to continuous operation. I think there was a rule of thumb I heard once that if you're not going to be in the room for more than about 10 minutes that it's generally more cost effective to turn the lights off than leave them when comparing energy usage to tube life.

Modern driver designs are at least an order of magnitude better than even a couple years ago though so this issue is mitigated significantly.