US4713652A
Expired / Lapsed
US
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Electrical apparatus
Assignee: EMI Group Electronics Ltd
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Filing: 1985-11-19
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Granted: 1987-12-15
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Expires: 2005-11-19
Abstract
Abstract An electrical apparatus for monitoring electrical continuity includes a number of input circuits each associated with a respective arm of a multi-phase rectifier circuit the continuity of which is to be monitored. Each input circuit includes a comparator which generates a train of pulses P while an input current persists in the arm. If a discontinuity arises in an arm for a first preset interval of time a monostable in that arm generates a first trigger signal. If the discontinuity persists for a further preset interval of time another monostable, common to all the arms, triggers an alarm via a bistable circuit.
Inventors
- 👤 Steven J. French
- 👤 David L. Neasham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:00
CPC Classifications
H; H02; H02H; H02H7/00; H02H7/10; H02H7/12; H02H7/125; H02H7/1255; G; G01; G01R; G01R31/00; G01R31/50; G01R31/52; G01R31/54
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
141 words
An electrical apparatus suitable for monitoring electrical continuity of the input arms of a rectifier circuit, the apparatus comprising a plurality of pulse generating means, each being associated with a respective input arm of the rectifier circuit and generating a succession of electrical pulses while an electrical signal prevails in said input arm, and a plurality of first timing circuits, each being associated with a respective input arm of the rectifier circuit and generating a respective first electrical signal provided an interruption of a respective succession of electrical pulses persists for a first part of a preset interval of time, and a second timing circuit, being responsive to a said first electrical signal generated by any of said plurality of first timing circuits, to initiate an alarm signal provided said interruption persists for the remainder of said preset interval of time.
Claim 2
Dependent Claim
141 words
An electrical apparatus suitable for monitoring electrical continuity of the input arms of a rectifier circuit, the apparatus comprising a plurality of pulse generating means, each being associated with a respective input arm of the rectifier circuit and generating a succession of electrical pulses while an electrical signal prevails in said input arm, and a plurality of first timing circuits, each being associated with a respective input arm of the rectifier circuit and generating a respective first electrical signal provided an interruption of a respective succession of electrical pulses persists for a first part of a preset interval of time, and a second timing circuit, being responsive to a said first electrical signal generated by any of said plurality of first timing circuits, to initiate an alarm signal provided said interruption persists for the remainder of said preset interval of time.
Claim 3
Dependent Claim
55 words
An electrical apparatus according to claim 1 wherein each of said first timing circuits includes a respective first monostable circuit and said second timing circuit includes a second monostable circuit, said first and second monostable circuits having time constants which are related to said first and remaining parts respectively of said preset interval of time.
Claim 4
Dependent Claim
41 words
An electrical apparatus according to claim 2 wherein said second timing circuit is capable of generating an alarm signal provided also that the magnitude of a said electrical signal in at least one of the input arms exceeds a threshold value.
Claim 5
Dependent Claim
50 words
An electrical apparatus according to claim 3 wherein each said current sensing means includes a circuit responsive to the positive and negative half cycles of a supply wave form and generating, at different output locations, respective electrical signals related to the current in the respective arm of the rectifier circuit.
Claim 6
Dependent Claim
47 words
An electrical apparatus according to claim 4 suitable for monitoring electrical continuity of the input arms of a rectifier circuit connected to a multiphase power supply, the apparatus including a plurality of said current sensing means, each being associated with a respective phase of the multiphase supply.
Claim 7
Dependent Claim
23 words
An electrical apparatus according to claim 3 including a respective current sensing means for coupling to each input arm of the rectifier circuit.
Claim 8
Dependent Claim
23 words
An electrical apparatus according to claim 2 including a respective current sensing means for coupling to each input arm of the rectifier circuit.
Claim 9
Dependent Claim
50 words
An electrical apparatus according to claim 7 wherein each said current sensing means includes a circuit responsive to the positive and negative half cycles of a supply wave form and generating, at different output locations, respective electrical signals related to the current in the respective arm of the rectifier circuit.
Claim 10
Dependent Claim
47 words
An electrical apparatus according to claim 8 suitable for monitoring electrical continuity of the input arms of a rectifier circuit connected to a multiphase power supply, the apparatus including a plurality of said current sensing means, each being associated with a respective phase of the multiphase supply.
Claim 11
Dependent Claim
23 words
An electrical apparatus according to claim 1 including a respective current sensing means for coupling to each input arm of the rectifier circuit.
Claim 12
Dependent Claim
50 words
An electrical apparatus according to claim 10 wherein each said current sensing means includes a circuit responsive to the positive and negative half cycles of a supply wave form and generating, at different output location, respective electrical signals related to the current in the respective arm of the rectifier circuit.
Claim 13
Dependent Claim
47 words
An electrical apparatus according to claim 11 suitable for monitoring electrical continuity of the input arms of a rectifier circuit connected to a multiphase power supply, the apparatus including a plurality of said current sensing means, each being associated with a respective phase of the multiphase supply.
Claim 14
Dependent Claim
41 words
An electrical apparatus according to claim 1 wherein said second timing circuit is capable of generating an alarm signal provided also that the magnitude of a said electrical signal in at least one of the input arms exceeds a threshold value.
Claim 15
Dependent Claim
22 words
An electrical apparatus according to 13 including a respective current sensing means for coupling to each input arm of the rectifier circuit.
Claim 16
Dependent Claim
22 words
An electrical apparatus according to 13 including a respective current sensing means for coupling to each input arm of the rectifier circuit.
Claim 17
Dependent Claim
50 words
An electrical apparatus according to claim 14 wherein each said current sensing means includes a circuit responsive to the positive and negative half cycles of a supply wave form and generating, at different output locations, respective electrical signals related to the current in the respective arm of the rectifier circuit.
Claim 18
Dependent Claim
47 words
An electrical apparatus according to claim 15 suitable for monitoring electrical continuity of the input arms of a rectifier circuit connected to a multiphase power supply, the apparatus including a plurality of said current sensing means, each being associated with a respective phase of the multiphase supply.
Claim 19
Dependent Claim
149 words
A power supply including a rectifier circuit and an electrical apparatus for monitoring electrical continuity of the input arms of the rectifier circuit, wherein said electrical apparatus comprises a plurality of pulse generating means, each being associated with a respective input arm of the rectifier circuit and generating a succession of electrical pulses while an electrical signal prevails in said input arm, a plurality of first timing circuits, each being associated with a respective input arm of the rectifier circuit and generating a respective first electrical signal provided an interruption of a respective succession of electrical pulses persists for a first part of a preset interval of time, and a second timing circuit, being responsive to a said first electrical signal generated by any of said plurality of first timing circuits, to initiate an alarm signal provided, said interrruption persists for the remainder of said preset interval of time.
Claim 20
Dependent Claim
149 words
A power supply including a rectifier circuit and an electrical apparatus for monitoring electrical continuity of the input arms of the rectifier circuit, wherein said electrical apparatus comprises a plurality of pulse generating means, each being associated with a respective input arm of the rectifier circuit and generating a succession of electrical pulses while an electrical signal prevails in said input arm, a plurality of first timing circuits, each being associated with a respective input arm of the rectifier circuit and generating a respective first electrical signal provided an interruption of a respective succession of electrical pulses persists for a first part of a preset interval of time, and a second timing circuit, being responsive to a said first electrical signal generated by any of said plurality of first timing circuits, to initiate an alarm signal provided, said interrruption persists for the remainder of said preset interval of time.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-12-14 | 1991-06-15 | 1991-12-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-12-14 | 1995-06-15 | 1995-12-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-12-14 | 1999-06-15 | 1999-12-15 | $7700.00 | Window Closed / Lapsed |