Alternating-current detection circuit

An AC detection circuit, including a live wire input end and a neutral wire input end; a first diode and a second diode being both Zener diodes and with anodes connected to each other; a first resistor and a second resistor; a rectification module connected to the live wire input end and the neutral wire input end; a power supply for supplying power; a current mirror module with a current value at the first output end and a current value at the second output end having a fixed ratio; a unidirectional conduction module, configured to enable unidirectional conduction of the current from the current mirror module to the first diode; and a current comparison module, including an oscillator, a timer, a current comparator and a reference current source, and configured to compare the current value of the second output end of the current mirror module with a reference current value.