US3795842A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit for monitoring voltages in a polyphase electrical supply
Assignee: Univ AMP Inc
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Filing: 1972-06-09
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Granted: 1974-03-05
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Expires: 1992-06-09
Abstract
Abstract A triac, a pair of diacs, a neon bulb and a photocell monitor all of the voltages in a polyphase electrical supply and disconnect a load when any of the voltages decrease below a predetermined threshold value.
Inventors
- 👤 F Kovacs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 02:26
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/24; H02H3/253
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
273 words
A circuit for monitoring voltages in a polyphase electrical supply and for protecting a load from a decrease in voltage on any phase, said circuit being designed for use with a contactor having a coil and first, second and third switches, said circuit comprising: first, second and third input terminals, each of said switches being connected between said load and a corresponding one of said input terminals; a triac having first and second terminals and a gate, said coil of said contactor being connected between said first input terminal and said first terminal of said triac, said second terminal of said triac being connected to said second input terminal; a photocell; a neon bulb, said bulb being mounted adjacent said photo-cell so that light from said bulb activates said photocell when said bulb is energized; first and second diacs each having first and second terminals; first and second rheostats, said neon bulb being connected between said first terminal of said first diac and said second input terminal, said first rheostat being connected between said second terminal of said first diac and said third input terminal; first and second resistors, said first resistor being connected between said second input terminal and said second terminal of said first diac, said second resistor being connected between said first terminal of said second diac and a first lead of said photocell, a second lead of said photocell being coupled to said first input terminal, said second terminal of said second diac being connected to said gate of said triac, said second rheostat being connected between said second input terminal and said first terminal of said second diac.
Claim 2
Dependent Claim
273 words
A circuit for monitoring voltages in a polyphase electrical supply and for protecting a load from a decrease in voltage on any phase, said circuit being designed for use with a contactor having a coil and first, second and third switches, said circuit comprising: first, second and third input terminals, each of said switches being connected between said load and a corresponding one of said input terminals; a triac having first and second terminals and a gate, said coil of said contactor being connected between said first input terminal and said first terminal of said triac, said second terminal of said triac being connected to said second input terminal; a photocell; a neon bulb, said bulb being mounted adjacent said photo-cell so that light from said bulb activates said photocell when said bulb is energized; first and second diacs each having first and second terminals; first and second rheostats, said neon bulb being connected between said first terminal of said first diac and said second input terminal, said first rheostat being connected between said second terminal of said first diac and said third input terminal; first and second resistors, said first resistor being connected between said second input terminal and said second terminal of said first diac, said second resistor being connected between said first terminal of said second diac and a first lead of said photocell, a second lead of said photocell being coupled to said first input terminal, said second terminal of said second diac being connected to said gate of said triac, said second rheostat being connected between said second input terminal and said first terminal of said second diac.
Claim 3
Dependent Claim
37 words
A circuit for monitoring voltages in a polyphase electrical supply as defined in claim 1 including: a third resistor, said third resistor being connected between said second input terminal and said first terminal of said second diac.
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) | 1977-03-04 | 1977-09-03 | 1978-03-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-04 | 1981-09-03 | 1982-03-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-04 | 1985-09-03 | 1986-03-05 | $7700.00 | Window Closed / Lapsed |