The invention relates to an AC charged induction device, which comprises a power circuit, a signal receiving circuit, a gear control circuit, a signal processing circuit, an MCU control circuit, an alarming circuit and an MCU input circuit, wherein the MCU control circuit outputs a gear control signal to the gear control circuit for gear selection; the gear control circuit is electrically connected with the signal receiving circuit for controlling a sampling resistor accessed to the signal processing circuit; the signal receiving circuit detects electric signals, and the detected electric signals are transmitted to the signal processing circuit; the signal processing circuit receives the electric signals detected by the signal receiving circuit, the electric signals are amplified and filtered and then transmitted to the MCU input circuit, conduction of a triode is controlled, signals are outputted to the MCU control circuit, the MCU control circuit is used for receiving signals of the MCU input circuit, analyzing the voltage grade of the detected electric signals and controlling the alarming circuit to give an alarm. While whether the device is charged is detected, the voltage grade of the device can be detected.