[goms187]

i was thinking would it be possible to run an op amp off the ide activity header and run multiple leds off the op amp then....the only thing im not sure on is what would be used as the common between the op amp and the ide header...im not sure if anyone else understands this but if you do and you can figure this out for me please post back.....thanks

[goms187]

i think i will be using an lm318 as the op amp

[pby5cat]

this could be of help if I read you right.

[goms187]

not exactly what im looking for but might be even easier than the way i was going .....thanks

[Overload]

A MOSFET of the IRF530 or IRF 630 should do the trick. i have done this with simular projects. i made a wal-mart neon flash with the HDD LED. hook the led header to the gate and the load (LEDs and resistor) in series with the supply and the source and drain.

[goms187]

could i get alil schematic

[Overload]

sorry i can't post pictures

[KILLorBE]

Originally posted by Overload
sorry i can't post pictures

You can upload pictures at The Forum Is Down

goms187 is this what you're looking for? (taken from this thread).

I've made a schematic that certainly will work and it's 99.9% Idiot-proof (As long as you connect the 2 wires from your MOBO to the right 2 pins on the optocoupler, there's NO WAY you could kill your MOBO).


Explanation:
R1 isn't necessary (It's there for testing purposes, IE If you hook it up to a 12V PSU to test the circuit (In that case it should be 680 Ohm)).
R2 should be 1.5K - 2K Ohm (Slightly larger should work as well....at least it doesn't do any damage).
T1 is a BD139 (Any other NPN transistor will work, but this one is pretty common and can handle enough power for most applications w/o (passive) cooling).

So you only need to calculate the resistor for the HDD LED (R3, R4, R5 etc..) (Calculator can be found Here).
The optocoupler can be either a TIL111, 4N25, CNY17-4 or similar (Most use the same pin-outs...at least the 3 I mentioned do).

If you don't see a pic, I'll upload it again.

[Overload]

Thanks KILLorBE

That looks better than mine, but here is how i did it
http://www.theforumisdown.com/upload...103/schem1.jpg