My CCFL and Mobo pinouts

[Dgephri]

lets just get some basic Motherboard information straight:

Most boards use 3V for the LEDs...and less than 20mA. Your CCFl takes 12Volts, and likely half (.5A or 500mA) an amp in DRAW. As I understand the process, the CCFl will draw as much as possible from the motherboard, even though it likely has a limiting resistor somewhere on the LED circuit.

Your CCFls won't light up at only 3Volts. And you run the risk of drawing too much from your motherboard LED circuit as well. Do some reading, and get a proper relay.

I have safely used a Crydom DMO 063 to control as many as 6 CCFls. You can't, shouldn't, and hopefully won't, hook it up to your motherboard directly.

[Malatory]

Looking thought this thread and one 1 person is trying to help and that is Dgephri.

You will likely kill your mobo hooking up a CCFL to it. As stated above. They are 12V and the header your trying to use is only 3V.

CCFL are made to run off the same molex conector as Hard drives. If you just bough a CCFL and no Inverter then your trying to add a AC device to a DC power. Yet another way to kill things that you wanted to keep.

[slaveofconvention]

The best, safest, and most reliable way to make a Cold Cathode act as a HD activity light would be to buy a very fast reacting relay, then wire the cathode kit up as normal, except using the relay instead of the manual switch (if it doesn't HAVE a switch then you can just cut EITHER (not both) of the power wires BEFORE the inverter and have the relay in there. Then you wire the relay to the motherboard.

When you buy the relay, make sure you....

1. Get one which will switch with 3v or less (as mentioned above, thats all a motherboard pin-out usually provides)
2. Can handle 12v DC across the switch (because thats what the cathodes run on)
3. Will react fast enough to actually have the light come on before it's turned off again.
4. If possible, I THINK you need to get a SPST (Single pole, single throw) relay as this will be easiest to wire up. It won't confuse you with extra terminals you don't need.

It definitely isnt as simple as connecting s CCFL tube to the mobo pinouts. I don't think it WOULD fry the board, but it definitely wont work.

Ask in your local electronics shop - they should be able to help.

[Dgephri]

use a Crydom DMO-063, 0-3V control line (like your motherboard pins)

0-60V load (you are only working 12V) up to 3Amps! $15, 4 pins, and you can do it. There are 555 timers, and some circuit designs that do basically the same thing.

I have personally used this relay to power up 3 pairs of CCFls, and currently run 2 4LED UV clusters (8 UV LEDs).