LED Wiring

[EnderWiggen22]

Hey. Just finishing up my cab, so I picked up 2 2.6 v 28mA red LEDs from Radioshack to use in the coindoor. I want to power them w/ my computers power supply. Does anyone know how to use the 5v or 12v lead to do this?

[Franco B]

You can use either 5v or 12v.

Using the LED series/parallel array wizard at http://led.linear1.org/led.wiz gives the following results:

5v




12v

[Neverending Project]

That calculator is a great tool. If you use 12V and hook them up in series, however, if one LED goes out then neither will light. You can still hook them in parallel using 12V by using 180Ohm resistors instead of the 270 in the diagram, FYI.

[EnderWiggen22]

Wow, Franco. That was incredibly straightfoward and helpful. Thank you

[EnderWiggen22]

One more question: Can I do the parallel wiring like this?

         + A -                    Key:
          l     l                   
          l     Z                  A : LED
          l     l                   
         + A -                   Z : Resistor
          l     l
          l     Z                  O : Power
          l     l
         O    G                  G : Ground

[Franco B]

Your welcome. Im no expert by any means but I have found that site really useful.

Once again im no expert but I dont think you can wire it like that as there are two reistors inline with the top LED. (I may be wrong here)

Could you not wire it like:



         + A - - -                  Key:
          l          l                   
          l         Z                   A : LED
          l          l                  
         + A - Z -                   Z : Resistor
          l          l
          l          |                  O : Power
          l          l
         O         G                  G : Ground

[EnderWiggen22]

Gotcha. Good catch (makes sense now). I'm obviously no expert either... so I certainly appreciate the assist (saves me lots o' tinker-troubleshoot time)