Patent US4031050A successfully refreshed from Google Patents.
Patent US3921064A successfully refreshed from Google Patents.
US3921064A
Expired / Lapsed
US
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Power source checker device
Assignee: Pentax Corp
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Filing: 1974-04-17
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Granted: 1975-11-18
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Expires: 1994-04-17
Abstract
Abstract This device provides for checking whether a power source terminal voltage exceeds a minimum requirement. A luminescent diode serves as a controllable indicator element for the device and also serves as a circuit element across which a reference voltage is developed. In operation, when the terminal voltage exceeds the minimum requirement, the reference voltage and a detection voltage differ in magnitude by at least a predetermined amount, a comparison circuit forms a positive feedback control signal, and a switching circuit responds thereto to close a positive feedback loop leading to an increase in both the current flowing through the diode and the reference voltage developed across it.
Inventors
- 👤 Chiharu Mori
- 👤 Masahiro Kawasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:10
CPC Classifications
G; G01; G01R; G01R15/00; G01R15/04; G01R19/00; G01R19/165; G01R19/16533; G01R19/16538; G01R19/16542; G01R31/00; G01R31/36; G01R31/374
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
212 words
A device for checking whether a power source terminal voltage exceeds a minimum requirement, which comprises: first and second current flow paths arranged in parallel to draw respective currents from the power source; the current flow paths including circuit elements arranged to provide reference and detection voltages that differ in magnitude by at least a predetermined amount when the terminal voltage exceeds the minimum requirement; a luminescent diode serving as one of the circuit elements, the diode being connected in the first current flow path so as to be forward biased and to have the reference voltage developed across it; the diode also serving as a controllable visual indicator, the diode lighting up when there is current flowing through it in excess of a threshold value; comparison circuit means having a first input connected to respond to the reference voltage developed across the diode, a second input connected to respond to the detection voltage, and an output for producing a positive feedback control signal when the reference and detection voltages differ by at least the predetermined amount; and switching circuit means responsive to the positive feedback control signal for closing a positive feedback loop so as to increase both the current flowing through the diode and the reference voltage developed across it.
Claim 2
Independent Claim
212 words
A device for checking whether a power source terminal voltage exceeds a minimum requirement, which comprises: first and second current flow paths arranged in parallel to draw respective currents from the power source; the current flow paths including circuit elements arranged to provide reference and detection voltages that differ in magnitude by at least a predetermined amount when the terminal voltage exceeds the minimum requirement; a luminescent diode serving as one of the circuit elements, the diode being connected in the first current flow path so as to be forward biased and to have the reference voltage developed across it; the diode also serving as a controllable visual indicator, the diode lighting up when there is current flowing through it in excess of a threshold value; comparison circuit means having a first input connected to respond to the reference voltage developed across the diode, a second input connected to respond to the detection voltage, and an output for producing a positive feedback control signal when the reference and detection voltages differ by at least the predetermined amount; and switching circuit means responsive to the positive feedback control signal for closing a positive feedback loop so as to increase both the current flowing through the diode and the reference voltage developed across it.
References Cited (Backward Citations)
US3670246A
Cited
US3832629A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-17 | 1979-05-19 | 1979-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-17 | 1983-05-19 | 1983-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-17 | 1987-05-19 | 1987-11-18 | $7700.00 | Window Closed / Lapsed |