Power supply circuit and power supply switching circuit of clock chip, power supply switching method and microwave oven

Abstract

The invention provides a power supply switching circuit of a clock chip. The power supply switching circuit comprises a first sampling terminal, a second sampling terminal, an output terminal and a switching control component, wherein the first sampling terminal is used for sampling a first direct current voltage; the second sampling terminal is used for sampling a second direct current voltage; the output terminal is connected to a power input terminal of the clock chip; the switching control component is used for comparing the first direct current voltage with the second direct current voltage and stopping or recovering connection between a second power supply terminal and the power input terminal of the clock chip. The invention further provides a corresponding power supply circuit of the clock chip, a microwave oven and a power supply switching method of the clock chip. By means of the technical scheme, different power sources can be used on different conditions, and the situation that the clock chip cannot be driven due to voltage drops can be avoided at the same time of ensuring that voltages of two power sources cannot flow backward mutually.

Description

technical field [0001] The invention relates to the technical field of power supply switching, in particular to a clock chip power supply switching circuit and a power supply switching method, a clock chip power supply circuit and a microwave oven. Background technique [0002] Also begin to install clock or perpetual calendar etc. on the electric appliance that people use daily, so that check time or date at any time. In the above-mentioned electrical appliances, such as microwave ovens, ovens, etc., the clock chip is directly powered by converting the mains power (alternating current) into direct current. However, when using mains power supply, if there is a power outage, the power plug falls off, etc., it may cause problems such as the need to reset the clock, causing inconvenience in use. [0003] In order to avoid frequent setting of the clock, you can consider setting up a backup power supply inside the electrical appliance, such as a button battery, so that after the...

AI Technical Summary

Problems solved by technology

However, the diode will cause a voltage drop of about 0.7V. When powered by a backup power supply, the actual input voltage value of the clock chip is only 2.3V. However, when the battery voltage drops to 2.5V or below, the clock chip can no longer work normally. As a result, it cannot supply power normally and will reduce the service life of the battery

Images