Patent ID: 7995033

Claim:
A power saving device adapted to automatically control a power source of a display for saving power, comprising: a first power connector adapted for connecting to a power source; a second power connector adapted for connecting to a power wire of the display; an infrared sensor for sensing user status and initiating a user status signal; an infrared coupling circuit connected to the infrared sensor; an amplifying circuit connected to the infrared coupling circuit for receiving the user status signal via the infrared coupling circuit and amplifying the user status signal; a wave shaping circuit connected to the amplifying circuit for receiving the amplified user status signal and converting the amplified user status signal to a voltage signal; and a switch circuit connected between the first power connector and the second power connector for receiving the voltage signal and converting the voltage signal to a control signal to control the connection between the first power connector and the second power connector; wherein the infrared coupling circuit comprises a first resistor and a coupling capacitor, an output terminal of the infrared sensor is connected to the amplifying circuit via the coupling capacitor, a ground terminal of the infrared sensor is grounded, the first resistor is connected between the output terminal and ground; and wherein the amplifying circuit includes an amplifier, a second resistor, a third resistor, a fourth resistor, and a fifth resistor, an inverting input terminal of the amplifier is connected to the infrared coupling circuit via the second resistor, a non-inverting input terminal of the amplifier is grounded, an output terminal of the amplifier is connected to the fourth resistor, fifth resistor, and ground in turn, a node between the fourth resistor and fifth resistor is connected to the inverting input terminal of the amplifier via the third resistor, the output terminal of the amplifier is also connected to the wave shaping circuit.