Electronic timepiece
AssigneeKabushiki Kaisha Suwa Seikosha
InventorHiroyuki Chihara
Life of this patent
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Abstract
Energy is conserved and the life of a lithium battery is extended in a timepiece by using a voltage reduction circuit for normal operation and a voltage regulating circuit during periods of heavy current drain, e.g., alarm or lamp function. A no-clock detector indicates the functional status of the timekeeping standard signal generator and voltage is raised to enable self-starting when oscillator signals are absent. A timer holds the regulated voltage on-line until operations stabilize after a period of heavy load and capacitors used in the voltage reduction circuit bolster the regulated voltage output during high load periods.
Claims16
In electronic timepiece including a time standard signal generating circuit, divider circuit means receiving said standard signal and outputting timekeeping signals of lower frequency, display means indicating at least timekeeping data, and a source of voltage, and at least one heavy load circuit intermittently operating and drawing a current from said voltage source, said heavy load current being large in comparison with normal operating current for timekeeping, the improvement therein comprising:
- a voltage reduction circuit, said reduction circuit providing a voltage output which is a division of said source voltage;
- a voltage regulation circuit, said regulation circuit providing a constant voltage output;
- power control circuit means for selecting one of said voltage reduction and voltage regulation circuits to provide voltage input to said timekeeping circuits, said regulation circuit being selected when said at least one heavy load circuit operates, said reduction circuit being selected when said at least one heavy load circuit is inoperative;
- and
- means for detecting operation of said at least one heavy load circuit.
Dependencies are inferred from the claim text.