Battery charging protection circuit composed of PTC components and overvoltage protection components

The PTC element and the overvoltage protection element coordinate to complete the following tasks: 1. Provide current protection against excessive current that may damage the FET and battery pack. 2. When the polarity is reversed, the PTC operates to limit the overcurrent caused by the forward conduction of the Zener diode. 3. When the overvoltage component provides protection against voltage overload, the component limits the conduction current.