Hi all,
I have a red-green LED of the 3-pin variety (as opposed to the ones with 2 pins that use reversed voltage to switch colour). I am wondering if I need 2 limiting resistors (one on each anode), or if a single resistor on the cathode is sufficient? As it is technically the same as two separate LEDs with their cathodes tied together, and therefore both can be on simultaneously (resulting in a yellowish hue), I am guessing that each side should really have its own resistor? But for practical purposes, is it really necessary?
I realise that I could use phased PWM to rapidly alternate between the two sides, and by ensuring only one or the other is on, get away with a single resistor - but do I need to go to these lengths?
Thanks
Graham
I have a red-green LED of the 3-pin variety (as opposed to the ones with 2 pins that use reversed voltage to switch colour). I am wondering if I need 2 limiting resistors (one on each anode), or if a single resistor on the cathode is sufficient? As it is technically the same as two separate LEDs with their cathodes tied together, and therefore both can be on simultaneously (resulting in a yellowish hue), I am guessing that each side should really have its own resistor? But for practical purposes, is it really necessary?
I realise that I could use phased PWM to rapidly alternate between the two sides, and by ensuring only one or the other is on, get away with a single resistor - but do I need to go to these lengths?
Thanks
Graham