Charging circuit and charger

The invention, which is applicable to the field of circuits, provides a charging circuit and a charger. The circuit comprises an electromagnetic compatibility circuit, a full-bridge rectifier and filter circuit, a main transformer transformation circuit, a rectifier and filter circuit, a reverse connection protection circuit, a sampling circuit, a feedback circuit and a PWM control circuit; the electromagnetic compatibility circuit is used for carrying out the high-frequency filtering of alternating-current input; the full-bridge rectifier and filter circuit is used for rectifying alternatingcurrent into pulsating direct current; the main transformer transformation circuit is used for storing and releasing electric energy according to PWM control signals; the rectifier and filter circuitis used for rectifying, filtering and outputting current; the reverse connection protection circuit is used for receiving regulated current and shutting off the charging circuit when the poles of a battery are reversely connected; the sampling circuit is used for acquiring voltage signal output; the feedback circuit is used for comparing the voltage signal with the reference voltage and then outputting a feedback signal; and the PWM control circuit is used for receiving the feedback signal and outputting a PWM control signal. By shutting off the charging circuit when the poles of the battery are reversely connected, the invention prevents the damage of the charger and the battery when the chargeable battery is reversely connected.