Step up to 12V from num/scroll/caps

[thatdecade]

Just thinking out loud, bear with me.

I'm looking to connect a Cold cathode fluorescent lamp to my ipac's LED harness.  Problem is that the light tube is 12V 700mA.

I know the ipac's LED connections are 5V and can only source 10mA, but I think I would be safe stepping up the voltage and using the pc power supply to source the current needed.



The only thing that worries me is the start up time lag (their not instantly on with power).  The bars do have a switch that makes them sound sensitive, but it looks pretty lame with the arcade but proves that the light bars can have fast reaction/start up times.
I may ditch the whole 12V problem by leaving it always powered with the pc and rewiring the sound portion of the tube's inverter circuit so it switches on/off with the keyboard's LEDs.

[SirPeale]

How about some background as to *why* you would want to do this.

[abzman2000]

presumably he wants to use something like scroll lock as an output pin, and use it to control the lights with software, or at least that's what I would do. 

[hanelyp]

Not quite.  That will only feed ~4.3V to the CCFL, the remainder on the 12V being lost in the transistor.  You want the CCFL on the collector (+12V side) of the transistor with the emitter (leg with the little arrow) going to ground.

[abzman2000]

you mean put the ccfl between 12v and the transistor, and hook ground directly into the transistor?