Patent ID: 8988234
Filing Date: 2015-03-24
Classification: G01R

Abstract:
1. An alarm system for alarming when there is a power leakage from an electronic device, comprising: a voltage decreasing circuit adapted to receive a first voltage from a live wire output terminal and output a second voltage; a switch circuit adapted to output a control signal when the power leakage is detected; wherein the switch circuit is electrically connected to a connection port; the connection port is electrically connected to the live wire output terminal and a neutral wire output terminal; and an alarm circuit adapted to receive the control signal and alarms; wherein the second voltage is provided to the alarm circuit; the connection port is electrically connected to the electronic device to provide power supply for the electronic device; wherein the voltage decreasing circuit comprises a first resistor, a zener diode, and a capacitor; the first resistor comprises a first resistor first terminal and a first resistor second terminal; the zener diode comprises a zener diode anode and a zener diode cathode; the first resistor first terminal is electrically connected to the live wire output terminal for receiving the first voltage; the first resistor second terminal is electrically connected to the zener diode anode; the zener diode cathode is adapted to output the second voltage; the zener diode cathode is electrically connected to the neutral wire output terminal via the capacitor; the switch circuit comprises a second resistor and a transistor; the connection port comprises a live wire input terminal, a neutral wire input terminal and a ground wire input terminal; the second resistor comprises a second resistor first terminal and a second resistor second terminal; the transistor comprises a transistor base, a transistor emitter and a transistor collector; the second resistor first terminal is electrically connected to the ground wire input terminal; the second resistor second terminal is electrically connected to the transistor base; the transistor collector is electrically connected to a connection point between the zener diode and the capacitor; and the transistor emitter is adapted to output the control signal.