I have ordered the LED's already but dont know how to find out what resistor I should use,100, 180, 220 ohm, just have no idea, and I have tried figuring out the calculator for this but not really understanding much of it.
So I was wounding if someone could please help me out
I am wanting to use 8-10 LED's
Assuming you will use the 12 volts of power the LED you selected according to the sites calculator you will need a 330 ohm .5 watt per LED. Or up to max of 3 in series a single 68 ohm .25 watt resistor in series with LED's. To put 8 in series you would need min 28 volts so max of 3 in series at 12 volts.
So how are you saying I should wire this up? From my understanding my options would be : One resistor per set of 3 LEDs will use one 68 ohm .25 w? (or) 8 LEDs with one 330 ohm .5 w?
Originally posted by Guarino: So much appreciated!!
No problem, glad to help. Remember to observe the polarity on LED, positive to Anode or it won't work.
What do you mean exactly?
Diodes will only allow current to flow in one direction So, you must connect them properly. A LED is a Light Emitting Diode. The longest lead is the Anode so positive is connected here. There is a flat spot also on most led's which is Cathode (shorter lead) and the negative is connected here. All LED's have a maximum continuous current, if exceeded they will burn out so, that is why resistor is needed to limit current. Different voltage require different resistor for same type LED.
