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Patent US5086366A successfully refreshed from Google Patents.
US5086366A
Expired / Lapsed
US
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Prealarm circuit breaker
Assignee: Mitsubishi Electric Corp
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Filing: 1991-03-14
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Granted: 1992-02-04
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Expires: 2011-03-14
Abstract
Abstract In a prealarm circuit breaker which can issue a prealarm signal before occurrence of trip, a pair-transistor is employed in a charging circuit of a pair of capacitors, one of which serves to make a time delay after pickup of an overcurrent and the other of which serves to make a time delay pickup of a current of prealarm level.
Inventors
- 👤 Kazuhiro Ishii
- 👤 Kouji Hirotsune
- 👤 Ichiro Arinobu
- 👤 Kazushi Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:14
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/08; H02H3/093; H02H3/02; H02H3/04
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
151 words
A prealarm circuit breaker, which has an overcurrent trip apparatus and a prealarm apparatus for issuing a prealarm signal before occurrence of trip, comprising: a pair-transistor having a pair of transistors; current detection means for making a detection voltage responding to a current flowing through said prealarm circuit breaker; voltage applying means for operating said pair-transistor in response to said detection voltage; a pair of resistors which are connected in series to said transistors, respectively; trip signal generation means connected in series to one of said transistors, said trip signal generation means issuing a trip signal with a predetermined delay time when said detection voltage exceeds a predetermined pickup voltage for trip; and prealarm signal generation means connected in series to the other one of said transistors, said signal generation means issuing the prealarm signal with a predetermined delay time when said detection voltage exceeds a predetermined pickup voltage for prealarm.
Claim 2
Dependent Claim
151 words
A prealarm circuit breaker, which has an overcurrent trip apparatus and a prealarm apparatus for issuing a prealarm signal before occurrence of trip, comprising: a pair-transistor having a pair of transistors; current detection means for making a detection voltage responding to a current flowing through said prealarm circuit breaker; voltage applying means for operating said pair-transistor in response to said detection voltage; a pair of resistors which are connected in series to said transistors, respectively; trip signal generation means connected in series to one of said transistors, said trip signal generation means issuing a trip signal with a predetermined delay time when said detection voltage exceeds a predetermined pickup voltage for trip; and prealarm signal generation means connected in series to the other one of said transistors, said signal generation means issuing the prealarm signal with a predetermined delay time when said detection voltage exceeds a predetermined pickup voltage for prealarm.
Claim 3
Dependent Claim
35 words
A prealarm circuit breaker in accordance with claim 1, wherein each of said predetermined delay times is dependent on a time for charging a capacitor through each of said transistors and each of said resistors.
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) | 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 |