How to power external LEDs?...Changed Subject Line..

[Lumpy]

Okay boys..... I need some ideas...

I'm in the process of builing a showcase control panel that can be put away when not in use.  Here's my problem.  I have the TV and computer in my entertainment center and then connect the control panel through my USB Ipac.  My question is how do I go about running power to the control panel to light my LEDs?  I bought the LED acrylic footsteps to light four buttons and two LED lazer cannons for my track ball.  Do I just buy more wire and extend one of the power supply leads to the control panel or is there a way for me to put a computer power supply in the control panel and fire it up without it being attached to a motherboard?  Then I would just have two wires running out of the control panel ( one usb and one power.)

Any and all suggestions welcome.

 

[Psychosylph]

I know it is possible to run a PSU w/o a motherboard; you just have to put a wire (usually piece of paperclip) from one ATX molex port to another.  You'd have to look up which ports, though.  Don't know if that is the best solution, though.

[SirPeale]

Short out the green wire with any black wire on an ATX power supply.  I wouldn't recommend a paper clip as you could short it on something.  Use a quicktap, or cut the wires and wire nut them together.  

Does seem kind of overkill to have another whole PS just to power a few lights.  You could make an extention cable from an unused power header off your existing PS.  That wouldn't be hard.

[TheTick]

You DO NOT need another power supply.

I have the same setup running right now on my "arcade podium" (the front half of a showcase style cab).  I have a single USB extension cable running out of it to the PC. My coin door has +5v LEDs lighting up the reject switches.  Solution: tap into the power from the IPAC.

I don't have a handy link ready, but if you check Andy's site, he's has a diagram that shows you the correct pins to use.

[Lumpy]

I guess I have a few more details with the responses so far.

1.  I would like to be able to turn the lights on and off.  If I run an extension off the computer power supply how would I achive this?  I don't know much about wiring and don't feel like frying myself.  That's why I thought of a second powersupply that I can turn on and off when I want to.  The 4 LEDs that are suppose to be computer feet actually have an on/off button.  But I don't know what to do with the Lazer Cannons on the trackball.

2.  I went to Andy's site and found the link.  Would that be able to power two LED cannons and the four LEDs?

Thanks

Modified Title....thanks Tick....  

[TheTick]

Four to Eight LEDs shouldn't be a problem. Never heard of a LED cannon, I assume its just a different profile.

As far as turning them off, Andy's instructions are for leaving them on. However, if you look at the diagram is shows you leads for NumLock, ScrollLock, and CapsLock. My LEDs are wired to NumLock. If I want the LEDs on I just have to make sure I switch NumLock on before I launch a game. Once the ROMs are running MAME won't let you toggle the LEDs via the keyboard (However, it will usually leave them alone.. stay lit or stay off).

Oh... change the subject line of your first post and you might get more responses.
i.e. "How to power external LEDs?" or "How to power LEDs from USB?"

[StephenH]

Basically, connect them to your PC supply, or to an external power adaptor.

If the LED does not include an internal resistor, you need a resistor in series with it, to drop the voltage down to about 1.7V.

Note: Flasher LEDs need 5-7V

[shmokes]

If you're coming directly off a power supply or USB cable you can always wire to a switch and then to the LED rather than directly to an LED.  It's just as easy.  Just pick up a single pole switch.  Here's a couple pics of one I picked up for a few bucks at Home Depot to wire up a light table I built for my wife (she's a graphic design student).

[shmokes]

And the wiring...

[shmokes]

You can see, in the above picture, that the black wire, coming in from the right side of the picture is power, it hooks to one of the little metal things on the switch (I'm no electrician   ) and then the other black wire runs from the other little metal thing on the switch to my lights.  They're flourescent, of course, but it would work exactly the same.

[Lumpy]

Thanks for the pictures and description shmokes.  I understand there is power in the usb cable, but is there anyway to connect that to LEDs that have the molex power connection or would I need LEDs that already have a USB connection?