Help, I have a problem with my LED circuit.?
I am having problems with my LED project, I have 20 LEDs in parallel (2 branches of 10) with a 9v adapter as the power supply. The LEDs consist of 3 red, 3 blue, 3 green and 11 white LEDs. I used an LED calculator to determine that the resistor should be 18 ohms (I used the lowest voltage of LEDs, the red being 2.4V to do the calculation). It is in parallel so the circuit looks like the image (but with 20 LEDs).
So the problem is, all the LED are working fine until I add the red LEDs to the circuit, then only the red ones light up. How do I fix this.
I must confess that my knowledge of electronics is rather limited, I basically learned everything I know from hanging around Instructables. So any help would be appreciated, thanks.