Capacitor voltage-dropping power supply circuit and device thereof

Abstract

The invention discloses a capacitor voltage-dropping power supply circuit. The capacitor voltage-dropping power supply circuit comprises a capacitor voltage-dropping circuit and a voltage-stabilizing circuit, wherein the live wire end is connected with the capacitor voltage-dropping circuit, the capacitor voltage-dropping circuit is connected with the null wire end through the voltage-stabilizing circuit, the capacitor voltage-dropping circuit and the voltage-stabilizing circuit are separately connected with an external processor, the capacitor voltage-dropping circuit is used to provide a preset small capacitance when the processor is idle and provide a preset large capacitance when the processor works, and the voltage-stabilizing circuit has lower voltage regulation load voltage when the processor is idle and has larger voltage regulation load voltage when the processor works. The invention discloses a device adopting the capacitor voltage-dropping power supply circuit. The capacitor voltage-dropping power supply circuit and device thereof of the invention can effectively reduce the stand-by power consumption, the stand-by power consumption can be less than 0.5W, and the circuit and the device are applicable to the low cost capacitor voltage-dropping power supply scheme which conforms to the stand-by energy conservation demand of household appliances and have an important significance in the reduction of the cost.

Description

technical field [0001] The invention relates to a power supply circuit, in particular to a capacitor step-down power supply circuit with low standby power consumption and low cost. The present invention also relates to a device using the above-mentioned capacitive step-down power supply circuit. Background technique [0002] As we all know, the design scheme of reducing the standby power consumption to less than 0.5W by using the capacitor step-down power supply method has the advantage of being cheap, but to achieve the standby power consumption of less than 0.5W, the capacity of the step-down capacitor is very small, which brings a Obvious problems: the capacity of the step-down capacitor is too small, the supply current is also greatly reduced, and the load capacity is poor. When the load is slightly larger, the output voltage of the 5V Zener tube will be significantly reduced, which will affect the stability of the subsequent processor (CPU). Therefore, this scheme has...

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Problems solved by technology

[0002] As we all know, the design scheme of reducing the standby power consumption to less than 0.5W by using the capacitor step-down power supply method has the advantage of being cheap, but to achieve the standby power consumption of less than 0.5W, the capacity of the step-down capacitor is very small, which brings a Obvious problems: the capacity of the step-down capacitor is too small, the supply current is also greatly reduced, and the load capacity is poor

For the occasions where the load consumes a lot of power and the step-down capacitor must be greater than 0.68U / AC275V to meet its output current requirements, its standby power consumption is usually above 0.8W, which does not meet the requirements of low standby power consumption for energy saving and environmental protection

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