Patent ID: 6466519
Filing Date: 2002-10-15
Classification: G04C,H02J

Abstract:
An electronic apparatus comprising:a power supply; a capacitor for accumulating charge from said power supply; an electronic circuit selectively driven by the accumulated charge from said capacitor; an oscillating circuit; an oscillation detecting circuit for determining when said oscillating circuit is in an oscillating state; a voltage-comparing circuit for determining when the voltage of said capacitor is not less than a first reference voltage; a switching circuit responsive to a control input for selectively coupling said capacitor to drive said electronic circuit, whereby said electronic circuit is placed in a power-active mode, and for selectively decoupling said capacitor from said electronic circuit, whereby said electronic circuit is placed in an inactive mode; a power-supply-control unit having a control output coupled to said control input of said switching circuit, said power-supply-control unit being effective for transitioning said electronic circuit from said inactive mode to said active mode in response to the detection result from one of said oscillation detecting circuit and voltage-comparing circuit, and effective for transitioning said electronic circuit from said active mode to said inactive mode in response to the detected result from the other one of said oscillation detecting circuit and voltage-comparing circuit.