Patent US3814947A successfully refreshed from Google Patents.
US3814947A
Expired / Lapsed
US
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Electrical circuit for providing automatic alternate switching
Assignee: Individual
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Filing: 1973-05-21
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Granted: 1974-06-04
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Expires: 1993-05-21
Abstract
Abstract Alternate switching between two parallel circuits is accomplished by the use of a relay and an incandescent lamp in each circuit. Each circuit is routed through the energization coil of its own relay and the contact and off terminal of the relay in the other circuit to prevent simultaneous closure of both circuits. Increased resistance in the circuit in use due to temperature rise in the incandescent lamp causes the other circuit to close following any interruption of the current supply. Appropriate intermittent breaking of the supply circuit effects automatic alternate flip-flop type switching between circuits.
Inventors
- 👤 J Friedman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:18
CPC Classifications
G; G09; G09B; G09B23/00; G09B23/06; G09B23/18; G09B23/183
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
146 words
An electrical circuit for providing automatic alternate switching comprising an input, an output, first and second substantially identical incandescent lamps, first and second relays, each relay comprising an energization coil and a current carrying contact having on and off terminals, the off terminals of each relay being connected directly to each other and to said input, said first lamp, the energization coil of said first relay, the current carrying contact of said second relay and its off terminal being connected in series between the input and output, and, said second lamp, the energization coil of said second relay, the current carrying contact of said first relay and its off terminal being connected in series between the input and output, a source of electrical current connected between said input and ground, means for intermittently disconnecting said source of electrical current, and means connecting said output to ground.
Claim 2
Dependent Claim
146 words
An electrical circuit for providing automatic alternate switching comprising an input, an output, first and second substantially identical incandescent lamps, first and second relays, each relay comprising an energization coil and a current carrying contact having on and off terminals, the off terminals of each relay being connected directly to each other and to said input, said first lamp, the energization coil of said first relay, the current carrying contact of said second relay and its off terminal being connected in series between the input and output, and, said second lamp, the energization coil of said second relay, the current carrying contact of said first relay and its off terminal being connected in series between the input and output, a source of electrical current connected between said input and ground, means for intermittently disconnecting said source of electrical current, and means connecting said output to ground.
References Cited (Backward Citations)
US3065379A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-03 | 1977-12-03 | 1978-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-03 | 1981-12-03 | 1982-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-03 | 1985-12-03 | 1986-06-04 | $7700.00 | Window Closed / Lapsed |