Control method of single live line charging circuit, control circuit of single live line charging circuit and single live line charging circuit

A control circuit of a single live line charging circuit, wherein the single live line charging circuit comprises a first switch, a first conduction element, a first inductor, a second switch, a second conduction element, a third switch, a first input end and a second input end;

• the first input end is connected to a first end of the first switch through the second conduction element;
• the first switch, the first conduction element and the first inductor constitute a buck circuit;
• the first input end is connected to a reference ground through the second switch, the second input end is connected to the reference ground through the third switch, and an alternating current input is connected to the first input end through a load circuit;
• wherein when the control circuit receives a first signal, the control circuit controls the first switch, the first conduction element and the first inductor to work in a buck mode, and the control circuit controls both the second switch and the third switch to be turned off, wherein the first signal indicates a turn-off of the load circuit;
• when the control circuit receives a second signal, the control circuit controls an output end of the single live line charging circuit to be in a charging state when a voltage of the output end of the single live line charging circuit relative to the reference ground is lower than a first voltage threshold, the control circuit controls the output end of the single live line charging circuit to be in a non-charging state when the voltage of the output end of the single live line charging circuit rises to a second voltage threshold, and the output end of the single live line charging circuit returns to the charging state when the voltage of the output end of the single live line charging circuit decreases to the first voltage threshold, wherein the second signal indicates a turn-on of the load circuit;
• and
• the second voltage threshold is greater than the first voltage threshold;
• the first conduction element and the second conduction element are diodes or switches.