US3919616A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Constant voltage power supply
Assignee: Cooper Industries LLC
•
Filing: 1972-12-06
•
Granted: 1975-11-11
•
Expires: 1992-12-06
Abstract
Abstract A constant voltage, current limited power supply primarily intended for use as a single cell, nickel cadmium battery charger. The nickel cadmium cell has a temperature characteristic of approximately minus 1.1 mV/*F. The system disclosed herein also has substantially this same temperature characteristic due to taking advantage of the intrinsic temperature characteristic of a forward-biased base-emitter junction of a silicon transistor. A forward-biased base-emitter junction is used as a system voltage reference and the voltage feedback arrangement permits the output voltage to be substantially above the reference voltage without reflecting a magnified voltage characteristic at the output.
Inventors
- 👤 Joseph M Allison
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:56
CPC Classifications
G; G05; G05F; G05F1/00; G05F1/10; G05F1/46; G05F1/56; G05F1/565; G05F1/567; H; H02; H02J; H02J7/00; H02J7/90; H02J7/971; H02J7/975; H02J7/977; H02J7/96
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
155 words
A power supply circuit for charging a battery having a temperature-voltage coefficient comprising a voltage supply, a reference means connected to said voltage supply for controlling the voltage of said supply, said reference means having a temperature coefficient similar to the said temperature coefficient of said battery being charged, output means connected to said voltage source, a current source connected to said reference means, said current source being independent of the voltage of said battery being charged, a zener diode comprising said reference, a transistor, said transistor having a base, an emitter, and a collector, said base of said transistor being connected to said zener diode, means for connecting said base emitter voltage to a battery to be charged, said transistor and said zener being so connected that said output voltage is equal to said base emitter voltage plus a constant times said zener voltage and said constant is equal to or less than one.
Claim 2
Dependent Claim
155 words
A power supply circuit for charging a battery having a temperature-voltage coefficient comprising a voltage supply, a reference means connected to said voltage supply for controlling the voltage of said supply, said reference means having a temperature coefficient similar to the said temperature coefficient of said battery being charged, output means connected to said voltage source, a current source connected to said reference means, said current source being independent of the voltage of said battery being charged, a zener diode comprising said reference, a transistor, said transistor having a base, an emitter, and a collector, said base of said transistor being connected to said zener diode, means for connecting said base emitter voltage to a battery to be charged, said transistor and said zener being so connected that said output voltage is equal to said base emitter voltage plus a constant times said zener voltage and said constant is equal to or less than one.
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) | 1978-11-10 | 1979-05-12 | 1979-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-10 | 1983-05-12 | 1983-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-10 | 1987-05-12 | 1987-11-11 | $7700.00 | Window Closed / Lapsed |