Patent US3968426A successfully refreshed from Google Patents.
US3968426A
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US
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Method of A.C. insulation testing utilizing a variable inductive reactor in parallel with a test specimen
Assignee: Individual
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Filing: 1974-12-05
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Granted: 1976-07-06
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Expires: 1994-12-05
Abstract
Abstract Insulation is tested by the method of connecting a variable inductive reactor across a voltage supply in parallel with a test specimen. The inductance of the reactor is varied until its reactance equals that of the sample as indicated by the supply current to the parallel circuit.
Inventors
- 👤 Charles F. Ward, Jr.
- 👤 Norman L. Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 01:43
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/08; G01R31/12; G01R31/14; H; H01; H01F; H01F29/00; H01F29/08; H01F29/10
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
94 words
The method of destructive testing of a.c. insulation comprising connecting a variable inductive reactor across a voltage supply in parallel with a test specimen, monitoring the current supplied to the parallel circuit by said voltage supply, varying the inductance of the variable inductive reactor until its reactance equals that of, the specimen as indicated by the supply current to the parallel circuit becoming of minimum value, and adjusting the supply voltage to a predetermined greater magnitude so as to cause, upon breakdown of the insulation, a detectable burning thereof at the point of failure.
Claim 2
Independent Claim
94 words
The method of destructive testing of a.c. insulation comprising connecting a variable inductive reactor across a voltage supply in parallel with a test specimen, monitoring the current supplied to the parallel circuit by said voltage supply, varying the inductance of the variable inductive reactor until its reactance equals that of, the specimen as indicated by the supply current to the parallel circuit becoming of minimum value, and adjusting the supply voltage to a predetermined greater magnitude so as to cause, upon breakdown of the insulation, a detectable burning thereof at the point of failure.
Claim 3
Dependent Claim
13 words
The method of claim 1 in which a variable voltage supply is employed.
Claim 4
Dependent Claim
25 words
The method of claim 2 in which during breakdown test the specimen is subjected to a preselected increased voltage for a predetermined period of time.
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) | 1979-07-06 | 1980-01-05 | 1980-07-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-07-06 | 1984-01-05 | 1984-07-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-07-06 | 1988-01-05 | 1988-07-06 | $7700.00 | Window Closed / Lapsed |