In summary, it is very important to choose the correct resistor in an LED circuit design. Some factors that are important in the calculation are the number of LEDs, the current rating of the LEDs, and the power supply voltage. Ohm’s Law can then be used to select the correct power rating and resistance value. In selecting a resistor, make sure the LEDs are not overdriven past their rated current value as it will not necessarily increase brightness and will reduce LED shelf life. Also, some Riedon resistor designs that may prove useful in a circuit design are the axial-leaded wirewound UT-series, the aluminum-housed wirewound UAL-series, or the thin film PF2200 or PFS35 designs. All of these resistor designs are available through DigiKey.