Current regulator diodes are a type of diode which can be used to control the current flowing through a circuit. They consist of a cathode and an anode, and work by regulating the voltage between them. When a current is applied to the diode, the voltage across the diode remains constant. When the current increases, the current through the diode also increases, allowing for control of the current within the circuit. This makes current regulator diodes useful in applications such as power supplies, where constant current output is needed.