Surge current proof microwave oven circuit

Abstract

A surge current preventing circuit for microwave oven, which contains the first device and second device, when the surge current flows in the first device the stabilized current with the rising of temperature is provided to high and low voltage transformer, with the rising of temperature caused by first device the second has precedence over the first device to provide the stable current to high and low voltage transformer and inhibit the surge current for preventing temperature rising, so the power loss and over heat are reduced, the NTC thermistor is also used in said invention to reduce the cost and simplify the productive procedure.

Description

Technical field [0001] The present invention relates to a microwave oven, in particular to a circuit for preventing surge current in a microwave oven. In particular, it relates to an improved circuit for preventing inrush current in a microwave oven, which reduces the power loss caused by an early inrush current and can prevent an excessive temperature rise. Background technique [0002] Normally, the magnetron of a microwave oven generates microwaves after applying high voltage, and uses this microwave to cook food. [0003] Figure 1 to Figure 2 It is an exploded three-dimensional schematic diagram of a general microwave oven and a schematic structural diagram of a general magnetron drive circuit. Such as figure 1 and figure 2 As shown, the microwave oven door 120 seals the heating chamber 110, and the heating chamber 110 is supplied with microwaves to heat the food placed inside the heating chamber 110. An electric control room 100 for generating microwaves is provided on o...

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Problems solved by technology

but if Figure 4b As shown, the inrush current prevention circuit using the NTC thermistor R1 causes excessive temperature rise and power loss after the load current stabilizes.

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