Patent US3786342A successfully refreshed from Google Patents.
US3786342A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Battery discharge indicators
Assignee: TECH/OPS SEVCON Inc A DE CORP
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Filing: 1972-06-07
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Granted: 1974-01-15
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Expires: 1992-06-07
Abstract
Abstract A current-compensated battery discharge indicator comprises voltage sensing means operable to provide an indication when the battery voltage falls below a predetermined value, and current sensing means adapted to sense a magnetic field generated by load current drawn from the battery and operable upon increase of the load current to lower the predetermined value of the voltage at which the voltage sensing means is operable to provide the said indication. The current sensing means may comprise a ring core of magnetic material through which passes a cable carrying the load current, and a magneto-sensitive resistor disposed in an air-gap in the ring core.
Inventors
- 👤 L Molyneux
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:59
CPC Classifications
G; G01; G01R; G01R19/00; G01R19/165; G01R19/16533; G01R19/16538; G01R19/16542; H; H01; H01M; H01M10/00; H01M10/42; H01M10/48; H01M50/00; H01M50/50; H01M50/569; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
101 words
A battery discharge indicator comprising voltage sensing means adapted to be connected to a battery and operable to provide an indication when the battery voltage falls below a predetermined value, and current sensing means adapted to sense a magnetic field generated by load current drawn from the battery and operable upon increase of the load current drawn from the battery to lower the predetermined value of the voltage at which the voltage sensing means is operable to provide the said indication, said current sensing means being operable at substantially all levels of load current that may be drawn from the battery.
Claim 2
Dependent Claim
101 words
A battery discharge indicator comprising voltage sensing means adapted to be connected to a battery and operable to provide an indication when the battery voltage falls below a predetermined value, and current sensing means adapted to sense a magnetic field generated by load current drawn from the battery and operable upon increase of the load current drawn from the battery to lower the predetermined value of the voltage at which the voltage sensing means is operable to provide the said indication, said current sensing means being operable at substantially all levels of load current that may be drawn from the battery.
Claim 3
Dependent Claim
69 words
A battery discharge indicator as claimed in claim 1, in which the current sensing means comprises a core of magnetic mAterial positioned, in use, relative to a load current carrying cable connected to the battery so that, in operation, a magnetic field is generated in the core by load current flowing in the cable, and a magneto-sensitive device positioned so as to lie, in operation, in the magnetic field.
Claim 4
Dependent Claim
64 words
A battery discharge indicator as claimed in claim 2, in which the core of magnetic material is shaped to surround at least partially, in use, the load current carrying cable connected to the battery, so as to form a closed magnetic circuit enclosing the cable, and the magneto-sensitive device is connected to the core so as to be disposed within the closed magnetic circuit.
Claim 5
Dependent Claim
59 words
A battery discharge indicator as claimed in claim 3, in which the core is formed from a ring of magnetic material having a central aperture of a size sufficient to receive a load current carrying cable threaded, in use, through the ring, the ring being formed with a radially extending air gap in which the magneto-sensitive device is disposed.
Claim 6
Dependent Claim
30 words
A battery discharge indicator as claimed in claim 2 in which the magneto sensitive device is a magneto-sensitive resistor whose resistance varies with the magnetic field applied to the resistor.
Claim 7
Dependent Claim
86 words
A battery discharge indicator as claimed in claim 5, in which the voltage sensing means comprises a chain of resistors including the magneto-sensitive resistor forming a voltage divider adapted to be connected across the battery and arranged to provide an output voltage dependent on the voltage of the battery and the resistance of the magneto-sensitive resistor, and a voltage-responsive circuit arranged to receive the output voltage from the voltage divider and operable to provide the said indication when the output voltage falls below a preset value.
Claim 8
Dependent Claim
48 words
A battery discharge indicator as claimed in claim 6, in which the chain of resistors includes a variable resistor for adjusting the predetermined value of the battery voltage, for a given load current, at which the output voltage of the voltage divider is equal to the preset voltage.
Claim 9
Dependent Claim
92 words
A battery discharge indicator as claimed in claim 6, in which the voltage-responsive circuit comprises a relaxation oscillator including a programmed unijunction transistor the gate electrode of which is connected to the voltage divider so that, in use, a fall in the output voltage of the voltage divider below the preset value causes the programmed unijunction transistor to be rendered alternating conducting and non-conducting, and an indicating circuit including an indicating lamp adapted to be alterately energised and de-energised in response to the alternate conduction and non-conduction of the programmed unijunction transistor.
Claim 10
Dependent Claim
58 words
A battery discharge indicator as claimed in claim 8, in which there is provided a further indicating circuit including a further lamp and connected to the programmed unijunction transistor so that the further lamp is, in use, continuously energised when the programmed unijunction transistor is held non-conducted by the output voltage remaining in excess of the pre-set voltage.
Claim 11
Dependent Claim
72 words
A battery discharge indicator as claimed in claim 6, in which the voltage-responsive circuit comprises a bistable circuit adapted to be put in a first condition when the output voltage of the voltage divider exceeds the pre-set voltage and to be put in a second condition when the output voltage falls below the pre-set voltage, and indicating means operable to provide an indication when the bistable circuit is in its second condition.
Claim 12
Dependent Claim
103 words
A battery discharge indicator comprising voltage sensing means adapted to be connected to a battery and to sense the voltage thereof at all levels of load current, current sensing means adapted to sense a magnetic field generated by load current drawn from the battery, and circuit means adapted to provide an indication when the voltage sensed by the voltage sensing means falls below a value which is varied in dependence on the magnitude of the load current sensed by the current sensing mEans, said circuit means being so arranged that an increase in the load current causing a decrease in the said value.
Claim 13
Dependent Claim
103 words
A battery discharge indicator comprising voltage sensing means adapted to be connected to a battery and to sense the voltage thereof at all levels of load current, current sensing means adapted to sense a magnetic field generated by load current drawn from the battery, and circuit means adapted to provide an indication when the voltage sensed by the voltage sensing means falls below a value which is varied in dependence on the magnitude of the load current sensed by the current sensing mEans, said circuit means being so arranged that an increase in the load current causing a decrease in the said value.
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) | 1977-01-14 | 1977-07-16 | 1978-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-14 | 1981-07-16 | 1982-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-14 | 1985-07-16 | 1986-01-15 | $7700.00 | Window Closed / Lapsed |