Patent US4270508A successfully refreshed from Google Patents.
Patent US4160176A successfully refreshed from Google Patents.
US4160176A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic watch
Assignee: Seiko Instruments Inc
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Filing: 1977-08-23
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Granted: 1979-07-03
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Expires: 1997-08-23
Abstract
Abstract A circuit for detecting battery voltage for example in an electronic watch in order to provide a warning that the battery is almost depleted comprises two NOT circuits connected across the battery terminals. Each of the NOT circuits comprises a P-channel MOS transistor and an N-channel MOS transistor. The output of the first NOT circuit is connected to the input of the second NOT circuit and also through a biasing resistance to the input of the first NOT circuit. The output of the second NOT circuit is connected to circuitry for presenting a visual display when the output is inverted. When the voltage of the battery drops below a predetermined level, the output of the second NOT circuit is inverted to provide an indication that the battery is nearing depletion.
Inventors
- 👤 Norio Takahashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:44
CPC Classifications
G; G01; G01R; G01R19/00; G01R19/165; G01R19/16533; G01R19/16538; G01R19/16542; G04; G04C; G04C10/00; G04C10/04; H; H03; H03K; H03K17/00; H03K17/30; H03K17/302
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
86 words
A circuit for detecting battery voltage comprising first and second NOT circuits connected between positive and negative terminals of a battery, each of said circuits comprising a P-channel MOS transistor and an N-channel MOS transistor, means connecting the output of said first NOT circuit to the input of said second NOT transistor and resistance means interconnecting the output and input of said first NOT circuit, the output of said second NOT circuit being the output of said battery voltage connecting circuit for connection to indicating means.
Claim 2
Dependent Claim
86 words
A circuit for detecting battery voltage comprising first and second NOT circuits connected between positive and negative terminals of a battery, each of said circuits comprising a P-channel MOS transistor and an N-channel MOS transistor, means connecting the output of said first NOT circuit to the input of said second NOT transistor and resistance means interconnecting the output and input of said first NOT circuit, the output of said second NOT circuit being the output of said battery voltage connecting circuit for connection to indicating means.
Claim 3
Dependent Claim
36 words
A battery voltage detecting circuit according to claim 1, further comprising pulse controlled electronic switch means for intermittently connecting said first NOT circuit to a battery only when a pulse is applied to said switch means.
Claim 4
Dependent Claim
22 words
A battery voltage detecting circuit according to claim 1, comprising means for shifting the voltage detecting level of said voltage detecting circuit.
Claim 5
Dependent Claim
84 words
A battery voltage detecting circuit according to claim 1, in which each of said NOT circuits comprises a P-channel MOS transistor having its source connected with the positive terminal of said battery, an N-channel MOS transistor having its drain connected with the drain of said P-channel MOS transistor and its source connected with the negative terminal of said battery and means connecting the gates of said transistors with one another, the common drain connection of said transistors constituting the output of said NOT circuit.
Claim 6
Dependent Claim
41 words
A battery voltage detecting circuit according to claim 4, in which said resistance means connects the common drain of said MOS transistors comprising said first NOT circuit with the common gate connection of said MOS transistors comprising said first NOT circuit.
Claim 7
Dependent Claim
116 words
A battery voltage detecting circuit according to claim 4, further comprising pulse controlled switch means for connecting said first NOT circuit to said battery intermittently, said switch means comprising a second P-channel MOS transistor connecting the source of said P-channel MOS transistor of said first NOT circuit with said positive terminal, a second N-channel MOS transistor connecting the source of said N-channel MOS transistor of said first NOT circuit with said negative terminal, means including an inverter connecting the gates of said second P-channel MOS transistor with the gate of said second N-channel MOS transistor and means for supplying an intermittent pulse to the gate connections of said second P-channel transistor and said second N-channel transistor.
Claim 8
Dependent Claim
32 words
A battery voltage detecting circuit according to claim 4, further comprising a voltage lowering element connected between the source of each of said MOS transistors and respective ones of said battery terminals.
References Cited (Backward Citations)
US3628070A
Cited
US3898790A
Cited
US3949545A
Cited
US4001808A
Cited
US4037399A
Cited
US3999368A
Cited
US4041691A
Cited
US4024415A
Cited
US4043112A
Cited
US4032864A
Cited
US4074515A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-07-02 | 1983-01-01 | 1983-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-07-02 | 1987-01-01 | 1987-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-07-02 | 1991-01-01 | 1991-07-03 | $7700.00 | Window Closed / Lapsed |