One is a rectifier high voltage diode; The other is to play the role of high voltage protection. If the reverse voltage is too high, the diode will reverse breakdown, forming a path to protect the circuit. The rectifier high voltage diode has the following functions:

If the high voltage diode breaks down, the rectifier will blow the high voltage fuse. If the inside of the high-voltage diode burns out, there will be only AC high voltage and no DC high voltage. When a constant DC voltage is applied between the anode and the cathode, the electrons emitted by the cathode are affected by the positive potential of the anode and fly to the anode. In addition, under the action of magnetic field force and electric field force, there is a magnetic field perpendicular to the electric field in space, so the electrons do wheel swinging motion. Because there is a high-frequency electric field in the anode resonant cavity, an "electron cloud" rotating around the anode will be formed; When the rotating speed is synchronized with the high-frequency magnetic field, electrons give all energy to the high-frequency magnetic field, thus maintaining high-frequency oscillation. This high-frequency energy is output by the microwave energy output device and transmitted to the microwave oven cavity through the waveguide to heat food.