A few milliamps of current is enough to make an led glow. A current limiting resistor is a resistor that is used to reduce the current in a circuit. Optional Calculating The Current Limiting Resistor Levitation Infrared Emitter Power Supply Current Limiter Circuits Electronics Noyes Power supply circuit with feedback and current limiting transistor current limited circuit. Resistor current limiting . You would usually want to have a current limiting resistor in series with your led so that you can control the amount of current through the led. Although the circuit will work well with a wide range of values for r 2 a good choice is to design for a current through the zener diodes given by the following expression. Some components such as light emitting diodes are very sensitive to current. Limiting current into an led is very important. Home to