6 led mod question

lovablechevy · Post by **lovablechevy** » Thu Mar 06, 2008 12:04 pm

hello! i was wanting to do the 6 led mod to the psone screen that is talked about here.

i am getting these for my 6 leds.

i don't know much about electronics and was wondering what resistor i am supposed to use. is the 10 ohm one that ben uses in his 3 led mod ok, or does there need to be multiple resistors or just a different ohm...?

thanks for any help, guys!

Website · Post by **Life of Brian** » Thu Mar 06, 2008 7:24 pm

I always use this site when I don't feel like doing math: http://ledcalc.com/

It's pretty self explanatory, but if you need help just ask. You're probably going to be wiring the LEDs in parallel, so click on that.

lovablechevy · Post by **lovablechevy** » Fri Mar 07, 2008 8:52 am

Life of Brian wrote:I always use this site when I don't feel like doing math: http://ledcalc.com/

It's pretty self explanatory, but if you need help just ask. You're probably going to be wiring the LEDs in parallel, so click on that.

thanks, Life of Brian! i think i actually get how to use that.

Kurt_ · Post by **Kurt_** » Fri Mar 07, 2008 12:34 pm

In case you don't, you want 5V source voltage, 20mA current (for your run-of-the-mill LEDs) and 6 LEDs, in parallel. For the voltage drop, measure the voltage drop! I do believe it's 3.7V, I don't know where that number comes from but it is from some memory from way back when.

lovablechevy · Post by **lovablechevy** » Fri Mar 07, 2008 12:55 pm

Kurt_ wrote:In case you don't, you want 5V source voltage, 20mA current (for your run-of-the-mill LEDs) and 6 LEDs, in parallel. For the voltage drop, measure the voltage drop! I do believe it's 3.7V, I don't know where that number comes from but it is from some memory from way back when.

i had figured that out. but thanks!

i do have another question. the leds i have say their drop voltage is 3.4-3.8 and their mA is 20-30. is it ok to change these numbers around in the boxes a little bit so that i get an actual single led current of 20 mA...? or should i just use 3.4 with 20 mA and 3.8 with 30 mA?

i messed around and found that 3.8 volts with a desired led current of 22 gives me 20 mA if i use a 10 ohm 1/4 watt resistor...

thanks for not making me feel completely stupid, guys!

c_mon · Post by **c_mon** » Mon Mar 10, 2008 7:00 pm

Use one 10ohm resistor and you'll be fine.