PDA

View Full Version : Resistor Calculation Question



lookinginalderaanplaces
03-19-2016, 04:45 PM
Hi everyone,

I just have a question about if my current limiting resistor value. I am totally new at this, and I am sorry if I am asking a stupid questions or doing something wrong. I am planning an using a Li-Ion 13500 3.7V 1400mAh PCB Protected Rechargeable Battery Module and a green Luxeon Rebel Star which I think has a diode forward voltage of 3.4. I believe the LED is running at 1000mA. I put the numbers into a LED calculator and it gave me a 1ohm 2w resistor. Are my numbers correct? I also planning on getting a Nano Biscotte Sound Module V3. Will I need to add any numbers in my calculation to account for the soundboard? Is there anything I need to know for ordering everything?

darth_chasm
03-19-2016, 05:13 PM
That's a little high. Calculators always round up to 1 ohm if it is below that. You should always try to do the math yourself first.

(3.7-3.4)/1=0.3 you can go with a 0.47ohm resistor which I believe the store has.

No need for resistors for the board.

lookinginalderaanplaces
03-20-2016, 06:52 PM
Thanks. That really helps.