Patent ID: 9531183
Filing Date: 2016-12-27
CPC Classification: H02H

Claim Text:
1. A circuit of over-voltage protection used to prevent a power supply to provide an exorbitant voltage to an electronic cigarette, an electronic cigarette case or an electronic cigarette charger, wherein, said circuit comprises a DC input terminal, a DC output terminal, a voltage sampling circuit, a switch control circuit and a switch circuit; the voltage sampling circuit is electrically connected with the DC input terminal and the switch control circuit respectively; the switch control circuit is electrically connected with the switch circuit; the switch circuit is electrically connected with the DC input terminal, the DC output terminal and the switch control circuit respectively; the DC input terminal is used to receive direct current from the power supply; the DC output terminal is used to output direct current; the voltage sampling circuit is used to sampling the voltage of the DC input terminal; the switch control circuit is used to control the conductive or cutoff of the switch circuit; the switch circuit is used to output the direct current from the DC input terminal to the DC output terminal or not based on the control of the switch control circuit; wherein, said switch control circuit comprises a comparator; said switch circuit comprises a semiconductor switch; said semiconductor switch comprises a first pin, a second pin and a third pin; a first input of said comparator is connected with a reference voltage, a second input of said comparator is directly connected with said voltage sampling circuit, and an output of said comparator is directly connected with the first pin of said semiconductor switch, the second pin of the semiconductor switch is directly connected with the positive pole of the DC input terminal, and the third pin of said semiconductor switch is directly connected with the positive pole of the DC output terminal; if the voltage received by the second input of the comparator is over the reference voltage at the first input of the comparator, said comparator controls said semiconductor switch to be cut-off so that the DC output terminal can't be powered; and wherein the reference voltage can be set based on different electronic cigarettes, electronic cigarette cases or different electronic cigarette chargers.