Over-current and over-voltage protection circuit and method for an electronic cigarette

摘要

An over-current and over-voltage protection circuit for an electronic cigarette, comprising a battery and an interface, a control unit and a charging detection switch unit; the control unit is configured for calculating an actual charging current according to the first working voltage and determining whether the actual charging current exceeds a preset charging current threshold value, and sending a first charging controlling signal to the charging detection switch unit; the control unit is further configured for real-timely detecting an input voltage of the interface, determining whether the input voltage of the interface is in over-voltage status, and controlling a turned-on or turned-off operation of the charging detection switch unit. The over-current over-voltage protection circuit and method eliminate the security risk of the battery pole not having a charging management circuit in the non-normal charging status.

主权项

1. An over-current and over-voltage protection circuit for an electronic cigarette, comprising a battery and at least an interface, wherein the over-current and over-voltage protection circuit further comprises a control unit and a charging detection switch unit;
the control unit is electrically connected to the battery, the interface and the charging detection switch unit respectively; the charging detection switch unit is electrically connected to an end of the battery, and the interface is electrically connected to the charging detection switch unit and the battery respectively; the charging detection switch unit is configured for real-timely detecting a first working voltage generated by an actual charging current flowing through an internal resistor of the charging detection switch unit, and sending the first working voltage to the control unit; the control unit is configured for calculating the actual charging current according to the first working voltage and determining whether the actual charging current exceeds a preset charging current threshold value, and sending a first charging controlling signal to the charging detection switch unit; the control unit is further configured for real-timely detecting an input voltage of the interface, determining whether the input voltage of the interface is in over-voltage status, and sending a second charging controlling signal to the charging detection switch unit; the first charging controlling signal or the second charging controlling signal is configured for controlling a turned-on or turned-off operation of the charging detection switch unit.