ok what i want to try to do is, create a circuit that uses the parallel port to control my CCFL and fan voltages. I dont care about the software I can get that to work. But I need a circuit that will take the information from the parallel port, have a molex connection for power, and outputs of 1 or 2 molex connectors for CCFL's, and 1 or 2 molex connectors for controlling the fan voltages plugged into it.
I would like to be able to have software say, apply 7v to fan A, turn on the CCFL's, and apply 12v to fan B, and to be able to turn them all off, or all on (full power).
I know this is possible, but I am terriable at electronics.

Thanks for your time.

What kind of signals do you plan to use to control this? Just a single voltage on a pin? Also do you want any manual controls or indicators or will it just be hidden away somewhere?

it sounds cool and like it would take a lot of work

and it sounds like he is wanting to control it by software - right?

yes i will be writing software to control it in C++.

No indication will be needed of what the program is doing. I want to be using a simple voltage to turn on the relays (i think the voltage out on the parallel port is 5v + - 0.2v) 5v on the line means relay turns on.
Then in absent of voltage to turn off the relays.

I am guessing i will need about 4 relays.
1 for the CCFL
1 for 7v to the fans
1 for 12v to the fans
1 for expansion, a motorized something or another
Some cool things could probably be made with and and or gates, i can work on that, i just need pretty much a booster from the parallel port to power CCFL's and fans, that i will be able to control with software.

As for the software part, if say i want the CCFL to turn on I have a button that says "Turn on CCFL" and when pressed, the one pin on the parallel port turns on, causing the relay to turn on, causing the CCFL to turn on.

Thank you for your help.

i think all you would have to do is let a wire stick out of those pins and know which pins those are

correct?

yes i know that, what i was asking for was the diagram and componet list need to complete this project.

i guess i dont convay my ideas all that great sometimes.

Will the signal be a constant voltage (meaning when the signal is there, the fan is on) or will it be just a single pulse (single pulse turns on, single pulse turns off)?

constant voltage to keep the fan spinning at 7v (half power) and 12v (full power). I dont want pulsing voltage. Also enough the fan outputs would have to be able to power a couple fans.

Are you working on this Rabbit, trying to come up with a diagram?


Thank you for all your hard work.

Yeah, I should be able to make a diagram, seems like a pretty basic circuit, but I'm just trying to get a good idea of what you want.


From what I understand:
You send a signal to the parallel port. It will be on one of four pins (the signals for the ccfl, 7v, 15v, and expansion).
-Have a preference to what pins are used? Got to find out which pin is the ground, but do you have a preference to what is used? or atleast ones I shouldnt use?

I will probably have these go to transistors or relays (depends on what the currents will be) which will connect the power from the power supply to the fans. I doubt the port could supply enough current to up the voltage to run the fans.
Questions that arise:
-How much current do you plan on running through each line? (total maximum current of each fan or whatever else you want to hook up)
-Do you know the maximum current output of the pins of the port? (If not, I can probably search for it)

-Lastly, I'm not certain about the voltages of the red and yellow wires, anyone know what they are?

on a molex connector red = 12v and yellow = 5

just a note 12v not 15v

no there is like 6 data pins, i think?
go here http://www.hut.fi/Misc/Electronics/circuit...lel_output.html
and here.
http://www.codeproject.com/csharp/cspplcds.asp

i need the fan outputs to be able to control two of these
http://svc.com/120x38mmystech.html
on one output, so 4 fans in total.


and for the expansion i would want 12v i could always add a transformer later too.
and for the CCFL i found this:

Cold Cathode Tubes
Output voltage at 0V - 580V
5 ± 0.03mA
up to 2.9 Watts