US5086367A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit breaker
Assignee: Mitsubishi Electric Corp
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Filing: 1990-12-03
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Granted: 1992-02-04
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Expires: 2010-12-03
Abstract
Abstract A circuit breaker having the overcurrent tripping characteristic, which is capable of detecting an overcurrent flowing through main circuit between an ac source and a load. The circuit breaker comprises a pre-alarm circuit having a pre-alarm characteristic, a pre-alarm signal output circuit for producing an alarm in response to the output of the pre-alarm circuit and a photocoupler for controlling the data transmission between the circuits. The circuit breaker can detect the main circuit current before it becomes an overcurrent and generate the alarm accurately.
Inventors
- 👤 Kazuhiro Ishii
- 👤 Hideaki Moriwaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:03
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/08; H02H3/02; H02H3/04; H02H1/00; H02H1/0061; H02H1/0069
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
126 words
A circuit breaker operative to detect an overcurrent flowing through a main circuit between an AC source and a load, and to perform an overcurrent tripping function, said circuit breaker further comprising: a pre-alarm circuit with such a pre-alarming function as to generate an alarm output signal before a current flowing through a main circuit exceeds an overcurrent; a pre-alarm signal output circuit driven by said alarm output signal from the pre-alarm circuit and being operative to generate at least one of an audio and visual alarm; and a photo-coupler coupled between said pre-alarm circuit and said pre-alarm signal output circuit and being operative in such a direction as to block the transmission of a signal from the pre-alarm signal output circuit to the pre-alarm circuit.
Claim 2
Dependent Claim
126 words
A circuit breaker operative to detect an overcurrent flowing through a main circuit between an AC source and a load, and to perform an overcurrent tripping function, said circuit breaker further comprising: a pre-alarm circuit with such a pre-alarming function as to generate an alarm output signal before a current flowing through a main circuit exceeds an overcurrent; a pre-alarm signal output circuit driven by said alarm output signal from the pre-alarm circuit and being operative to generate at least one of an audio and visual alarm; and a photo-coupler coupled between said pre-alarm circuit and said pre-alarm signal output circuit and being operative in such a direction as to block the transmission of a signal from the pre-alarm signal output circuit to the pre-alarm circuit.
Claim 3
Dependent Claim
33 words
The circuit breaker as defined in claim 1 wherein said pre-alarm circuit produces the pre-alarm signal, when the main circuit current exceeds a value not larger than 70% of a rated current value.
Claim 4
Dependent Claim
31 words
The circuit breaker as defined in claim 1 wherein said photocoupler comprises a light emission diode coupled to said pre-alarm circuit and a phototransistor coupled to said pre-alarm signal output circuit.
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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) | 1995-02-03 | 1995-08-05 | 1996-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-02-03 | 1999-08-05 | 2000-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-02-03 | 2003-08-05 | 2004-02-04 | $7700.00 | Window Closed / Lapsed |