Title:
ELECTRONIC TIMEPIECE
Document Type and Number:
WIPO Patent Application WO/1995/027926
Kind Code:
A1
Abstract:
An electronic timepiece in which a stepping motor is controlled by pulse width modulation, using a power source comprising a solar cell and an electric double-layer capacitor, whose output voltage may fluctuate. The stepping motor is driven by pulses from a plurality of pulse generators, each producing pulses of a different width. The fluctuating output from the power source is detected, and depending on the output voltage, one out of the generators is selected to minimize the current of pulses that flows to drive the stepping motor. Accordingly, the stepping motor is always driven with the minimum necessary current, resulting in efficient use of the power source.
Inventors:
SATO KOICHI (JP)
Application Number:
PCT/JP1995/000679
Publication Date:
October 19, 1995
Filing Date:
April 06, 1995
Export Citation:
Assignee:
CITIZEN WATCH CO LTD (JP)
SATO KOICHI (JP)
SATO KOICHI (JP)
International Classes:
G04C3/14; (IPC1-7): G04C3/14
Foreign References:
| JPS5376069A | 1978-07-06 | |||
| JPS5387768A | 1978-08-02 | |||
| JPS618392B2 | 1986-03-13 | |||
| JPS5777984A | 1982-05-15 | |||
| JP4050548B2 | 2008-02-20 | |||
| JPS62289785A | 1987-12-16 | |||
| JPS62238484A | 1987-10-19 | |||
| JPH0480689A | 1992-03-13 | |||
| JPS61123991U | 1986-08-04 |
Other References:
Microfilm of the specification and drawings annexed to the written application of Japanese Utility Model Application No. 30789/1982, (Laid-open No. 134100/1983), (Rhythm Watch Co. Ltd.), 9 September 1983 (09.09.83), (Family: none).
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