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Powering multiple coin door LEDs off a 5v USB tap cable
Franco B:
--- Quote from: DeLuSioNal29 on November 30, 2008, 09:52:04 pm ---Tapping off the 12v power on your power supply is fine for normal coin door bulbs, but for LEDs you would want to use 5v. 12v would pop the leds.
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Just wanted to echo pretty much what Zebidee said.
It depends on what rating the LEDs are. The ones krick linked to are either 6v or 12v, you would have to use a 12v source for both bulbs but you would have to use resistor(s) to drop the voltage to 6v.
A 12v source is also fine to use for '5v' LEDs if its all you have availaible, but once again you would need to drop the voltage to 5v (or ~3.5v or whatever).
AFAIK each 12v lead from a typical supply guarantees 18A without triggering the current limit. So theoretically you could connect over 1500 (3.5v 25mA) LEDs in parallel to a 12v whilst drawing 12.5A
2600:
--- Quote from: krick on November 30, 2008, 08:28:02 pm ---Personally, I'd just tap off the 12v line in my power supply, but I know of someone who has a MAME cab based off a laptop. So powering off the USB is the only way to go unless they want to get a separate "wall wart" just for the coin door lights. I'm not sure what they're doing about a marquee either, come to think of it.
Frankly, I'd never try to power a cab off a laptop.
EDIT:
I think these are the HAPP lights you're referring to...
http://www.happcontrols.com/lighting/915wb61w.htm
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Those are them. As you can see they come in 6v or 12v variants with the built in resistor and a variety of colors.
krick:
--- Quote from: DeLuSioNal29 on November 30, 2008, 09:52:04 pm ---Tapping off the 12v power on your power supply is fine for normal coin door bulbs, but for LEDs you would want to use 5v. 12v would pop the leds.
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I'd use 12v LEDs when tapping the 12v line, of course.
In fact, here's my J-PAC mod to make it work...
http://mame.3feetunder.com/jpacmod/