I have an IR LED array which is powered by 12VDC. There are 10 chains wired in parallel. Each chain has 9 IR LEDs wired in series with a 10ohm 1/4 watt resistor. I also have 2 more chains wired in parallel, however these only have 6 LEDs.
I've used this tool to try and figure out an answer, but want to be sure I'm using the correct values: http://led.linear1.org/led.wiz It does suggest using a 1 Ohm 1/4 watt resistor for the chains of 9, however I only have 10 Ohm as my minimum.
The LEDs have a forward voltage of 1.5V and a current draw of 20mA (to the best of my knowledge).
I want to calculate the correct resistance value to use for these shorter chains.