[ay2b]

Originally Posted by Robert Cawthon

Could you point me to something that would tell me what resistances are required for which color? I am not extremely knowledgable about electronics design, but I can wire things up and solder them if given the design. This may be my first foray into design during the off season.

Read the spec on the LED -- it should give you a current and a voltage rating. The voltage rating will probably be somewhere in the 1.5-3.0 volt range; the current rating will probably be somewhere in the 10mA-60mA range. Suppose you have a 2v, 30mA LED.

Suppose you have a typical 5v supply, like on the driver station. Some of that voltage is "used up" by the LED, and some is "used up" by the resistor. The current through both will be the same. If the LED takes 2v, then the resistor takes 3v, to make the total of 5 from the supply. The Voltage/Current/Resistance formula is "V = I * R" (where V = Voltage, I = Current, R = Resistance). In our example, the voltage drop across the resistor is 3v and the current is 30mA (or 0.03A -- always make sure you get your decimal points right). 3v/0.03A = 100 ohms, so you would want a 100 ohm resistor.

I picked example numbers to make the math easy. If you get some value for a resistor and can't find common resistors with that value, just pick something close. The brightness of the LED is related to the current through it. If you pick a resistor which is too small, then the current will be higher and the LED will be brighter (and burn out sooner, up to the point of burning out right away). If you pick a resistor which is too big, then the current will be higher and the LED will be dimmer.