| 摘要 |
A standby power reduction device is provided, including a capacitor connected in parallel to a main switch controlling a switching mode power supply, without the necessity of providing a starting circuit, thereby reducing the cost and enabling miniaturization of product. The standby power reduction device includes a switching mode power supply (SMPS) receiving a power voltage rectified from AC power and generating a first output voltage and a second output voltage, a voltage-dividing circuit electrically connected to the SMPS, receiving the second output voltage and generating a divided voltage, a control circuit electrically connected to the voltage-dividing circuit, operated by the divided voltage and including a control transistor, a charging circuit electrically connected to the control circuit, operated by the control circuit and including a booster transistor, an EDLC electrically connected to the charging circuit and charging electric energy by the charging circuit, a voltage detector connected in parallel to the EDLC and detecting a charge voltage of the EDLC, a control switch electrically connected to the control circuit, operated by the control circuit and including a first switching transistor, a main switch operated by the control switch, controlling the operation of the SMPS and including a second switching transistor and a wired OR circuit, a photo-coupler controlling the operation of the main switch according to a command of a device operated by a first output voltage, and a first capacitor connected in parallel to the second switching transistor of the main switch, wherein the first capacitor operates the SMPS using a current flowing in the first capacitor when an electronic device is connected to the AC power for the first time. |
