Principle: Using the physical characteristics that the boiling point of water is affected by air pressure, food can be cooked faster and more thoroughly. Normal temperature 1 atmospheric pressure, normal boiling water is about 90- 105 degrees, the pressure in the electric pressure cooker is about 1.5 atmospheric pressure, and the boiling point of water is about 10- 130 degrees, so the food is cooked faster and more thoroughly.

Circuit principle: The schematic diagram of the electric pressure cooker circuit is shown in the following figure.

Turn on the power supply, press the key, the magnetic steel temperature limiter ST acts, the contact is closed, and the main heating circuit is connected through the main heater EH 1 and the overheating fuse FU. Turn the timer (mechanical clockwork type) PT clockwise to the gear with suitable holding time, the PT contact is closed, and the holding circuit is connected through holding heaters EH2 and FU. At this time, the heating indicator light HL 1 and the pressure maintaining indicator light HL2 are both on, and EH 1 and EH2 are heated at the same time, so that the temperature in the pot rises. When the working pressure reaches 100kpa, the ST action button is reset, the contact is disconnected, the power supply of the main heating circuit is cut off, HL 1 is turned off, and EH 1 stops heating. Since PT is counting, HL2 is still running, EH2 is still heating, and the pressure keeps starting. When the PT countdown is over, the PT contact is disconnected, HL2 is closed, EH2 stops heating, and the work is over.

At present, there are three main structures of electric pressure cookers on the market:

First, the prototype of pressure cooker is used for heating control, which is a more traditional way and has a complicated structure;

Second, the floating sealing structure that the inner pot is separated from the pot cover,

It solves many security problems and is the main structure in the market at present. However, there are many problems in the extension of its specifications to high power and large capacity, mainly in the range of 3, 4, 5 and 6 liters, and a few enterprises have developed 7 and 8 liters. Its pressure requirement should not be too high, generally controlled below 80Kpa, which has certain limitations;

The third is compression type, which is also a structure in which the inner pot is separated from the pot cover. Limited by patents, there are not many application enterprises and few products put on the market.