| 摘要 |
PURPOSE: An STB(Set-Top Box) and a TV embedding a power sensor are provided to turn on or off power remotely. CONSTITUTION: An on or off state checking device checks the on or off state of power of an electronic device such as a TV connected to an outlet. A coil is penetrated in one of TV power lines. The on or off state checking device has a bridge diode and a comparator. Since power quantity consumed in the TV is increased when the TV is turned on, a voltage detected in a coil sensor is increased. When the TV is turned off, the voltage of the coil sensor is decreased. A microcomputer detects the increase and decrease of the voltage, and judges the on or off state of the power. |
