The main characteristic of the diode is one-way conductivity, that is, under the action of forward voltage, the on-resistance is very small; Under the action of reverse voltage, the on-resistance is extremely large or infinite. Because the diode has the above characteristics, it is often used in the circuit in the voltage regulation principle of the rectifier and voltage regulation diode: the voltage regulation diode is characterized by the reverse voltage breakdown, and the voltage at both ends remains basically unchanged. The rectifier diode was damaged after the reverse breakdown. In this way, when the regulator is connected to the circuit, if the power supply voltage fluctuates, or the voltage changes at each point in the circuit for other reasons, the voltage at both ends of the load will remain basically unchanged.
    Rectifier diode and voltage regulator diode are PN semiconductor devices. The difference is that the rectifier diode uses one-way conductivity. The voltage regulator diode takes advantage of its reverse characteristics. Reverse join in the circuit.