Patent US4396889A successfully refreshed from Google Patents.
US4396889A
Expired / Lapsed
US
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Nonadjusting battery life detector
Assignee: Seiko Instruments Inc
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Filing: 1980-12-05
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Granted: 1983-08-02
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Expires: 2000-12-05
Abstract
Abstract A battery life detector operates by sensing battery voltage. The detector consists of a pair of series combinations of a constant voltage source and a constant current source which are connected to a terminal to which a battery voltage is applied. The constant voltage source outputs are connected to respective inputs of a differential amplifier.
Inventors
- 👤 Satoshi Arai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:30
CPC Classifications
G; G01; G01R; G01R19/00; G01R19/165; G01R19/16533; G01R19/16538; G01R19/16542
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
82 words
Nonadjusting battery life detector characterized in that a first constant voltage source for generating a constant voltage relative to the ground is connected to a battery in series through a first constant current source, a second constant voltage source for generating a constant voltage is connected to the battery in series through a second constant current source, and the constant output voltages from the first and second constant voltage sources are supplied to the two input terminals of a differential amplifier, respectively.
Claim 2
Dependent Claim
82 words
Nonadjusting battery life detector characterized in that a first constant voltage source for generating a constant voltage relative to the ground is connected to a battery in series through a first constant current source, a second constant voltage source for generating a constant voltage is connected to the battery in series through a second constant current source, and the constant output voltages from the first and second constant voltage sources are supplied to the two input terminals of a differential amplifier, respectively.
Claim 3
Dependent Claim
60 words
Nonadjusting battery life detector as claimed in claim 1 characterized in that a first sampling transistor is connected between the second constant current source and the ground, a second sampling transistor is connected between the first constant current source and the battery, and a collector of the second sampling transistor is connected to the battery terminal of the differential amplifier.
Claim 4
Dependent Claim
198 words
A battery life detector, comprising: a differential amplifier having a non-inverting input and an inverting input; a terminal for connection, in use, to a battery for receiving a battery voltage to be detected; a first constant voltage source having an output terminal connected to the non-inverting input of said differential amplifier for applying a constant voltage to the differential amplifier non-inverting input; a first constant current source connected in series with said first constant voltage source for applying a constant current to said first constant voltage source; a second constant voltage source having an output terminal connected to the inverting input of said differential amplifier for applying a constant voltage to the differential amplifier inverting input; a second constant current source connected in series with said second constant voltage source for applying a constant current to said second constant voltage source; and means for intermittently connecting the series combination of said first constant voltage source and said first constant current source to said terminal and for intermittently connecting the series combination of said second constant voltage source and said second constant current source to said terminal thereby to operate the battery detector circuit in a sampling operating mode.
Claim 5
Dependent Claim
198 words
A battery life detector, comprising: a differential amplifier having a non-inverting input and an inverting input; a terminal for connection, in use, to a battery for receiving a battery voltage to be detected; a first constant voltage source having an output terminal connected to the non-inverting input of said differential amplifier for applying a constant voltage to the differential amplifier non-inverting input; a first constant current source connected in series with said first constant voltage source for applying a constant current to said first constant voltage source; a second constant voltage source having an output terminal connected to the inverting input of said differential amplifier for applying a constant voltage to the differential amplifier inverting input; a second constant current source connected in series with said second constant voltage source for applying a constant current to said second constant voltage source; and means for intermittently connecting the series combination of said first constant voltage source and said first constant current source to said terminal and for intermittently connecting the series combination of said second constant voltage source and said second constant current source to said terminal thereby to operate the battery detector circuit in a sampling operating mode.
Claim 6
Dependent Claim
79 words
A battery life detector according to claim 3, wherein said means for intermittently connecting is comprised of a first transistor having a collector-emitter path connected in series with said second constant current source and ground, and a second transistor having two collectors with a first collector-emitter path connected in series with said first constant current source and said terminal and with a second collector-emitter path connected in series with a power input of said differential amplifier and said terminal.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-08-01 | 1987-01-31 | 1987-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-01 | 1991-01-31 | 1991-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-01 | 1995-01-31 | 1995-08-02 | $7700.00 | Window Closed / Lapsed |