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Ouch!
10-30-2007, 12:43 PM
Does anyone know How to use molex power to get 3volts to supply a couple of lasers.

I am building a mod which will include a couple of laser pointers that are normally powered by penlight batteries (2x1.5volts each) I want to power them from a molex but I don't know their resitance or current so ohm's law is not very helpful. I don't really want to include a battery pack in my mod, so I'm a bit stuck.

I have heard that these lasers are a bit fussy and that if you overload them they die very quickly. I'm gonna want to switch the lasers on and off idependantly and I've got the switches for that, but I'm not sure how to get 3 volts across them.

Can anybody help?

Ouch!
Collinstheclown
10-30-2007, 03:41 PM
The pin outs are 12V+, GND(-), GND(-), 5V+. Yellow being 12 and red being 5.

I know that 100Ohms is good for LEDs off the 5V, but LEDs arn't super picky. Hope that gives you a good idea of what to do. :)




-CollinstheClown
calumc
10-30-2007, 03:55 PM
well a laser is essentially the same as an LED-a diode. so if you had the stats just feed them into a normal LED calculator
Ouch!
10-30-2007, 04:17 PM
well a laser is essentially the same as an LED-a diode. so if you had the stats just feed them into a normal LED calculator

Looking on ebay where I bought one of the laser pointers I think it's 50 mW So I think I need a 47ohm resistor for that one (according to the LED calculator)

But, I'm only guessing.....and the other one I haven't a clue???

Oh well,

Ouch!
Spawn-Inc
10-30-2007, 05:31 PM
if you have any dollar store near buy they might have a cheap laser pointer that you could test out using some resistors.
Cannibal23
11-22-2007, 01:49 PM
check out the pinout of your atx connector of your power supply i believe there is a 3 volt line or a 3.3 volt line. not sure what spliceing into this will do to your pc so use this at your own risk
SgtM
11-22-2007, 10:06 PM
The pin outs are 12V+, GND(-), GND(-), 5V+. Yellow being 12 and red being 5.

I know that 100Ohms is good for LEDs off the 5V, but LEDs arn't super picky. Hope that gives you a good idea of what to do. :)




-CollinstheClown

^^
What he said.
Single LED calcultor:
http://led.linear1.org/1led.wiz

LED Array calculator:
http://led.linear1.org/led.wiz
Ouch!
11-23-2007, 06:38 AM
Thanks guys,

I think I'm just gonna have to take the plunge!

Keep an eye out for some updates soon.

Ouch!