US3710238A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sensitive sound fault meter and detector utilizing a double side band frequency current-generator
Assignee: Sola Basic Industries Inc
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Filing: 1971-04-27
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Granted: 1973-01-09
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Expires: 1991-04-27
Abstract
Abstract An electrical leakage detector indicating hazard level, for use in hospitals or the like, using a constant current generator having at least two side band frequencies on either side of the line frequency with a high impedance return to the ground from the constant current generator, together with a discriminator means to distinguish between the power line frequency and the two side band frequencies and for indicating departure of current from predetermined limits.
Inventors
- 👤 W Peterson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 11:24
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/16; H02H3/17; G; G01; G01R; G01R27/00; G01R27/02; G01R27/16; G01R27/18
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
128 words
In a leakage detector for a power system having two isolated conductors to be monitored, said power system having a predetermined frequency, the combination including a constant current generator having an output of at least two side band frequencies, one above and one below said predetermined frequency, means connecting one side of the output of said current generator to earth ground, means for feeding the other side of the output of said current generator through a transformer means to said two conductors, discriminator means, means connecting said transformer means to said discriminator means, said discriminator means distinguishing between said side band frequencies and the frequency of the line being monitored, and means connected to said discriminator means to indicate the impedance of the power systEm to earth ground.
Claim 2
Dependent Claim
128 words
In a leakage detector for a power system having two isolated conductors to be monitored, said power system having a predetermined frequency, the combination including a constant current generator having an output of at least two side band frequencies, one above and one below said predetermined frequency, means connecting one side of the output of said current generator to earth ground, means for feeding the other side of the output of said current generator through a transformer means to said two conductors, discriminator means, means connecting said transformer means to said discriminator means, said discriminator means distinguishing between said side band frequencies and the frequency of the line being monitored, and means connected to said discriminator means to indicate the impedance of the power systEm to earth ground.
Claim 3
Dependent Claim
28 words
In a leakage detector as claimed in claim 1 and including means to indicate when the impedance to earth ground is more os less than a predetermined value.
Claim 4
Dependent Claim
23 words
In a leakage detector as claimed in claim 1 and wherein the constant current generator includes an operational amplifier in a closed loop.
Claim 5
Dependent Claim
22 words
In a leakage detector as claimed in claim 3 wherein the constant current generator is driven by double side band signal means.
Claim 6
Dependent Claim
27 words
In a leakage detector as claimed in claim 1 wherein the discriminator means includes filter means to distinguish between the side band frequencies and said predetermined frequency.
Claim 7
Dependent Claim
36 words
In a leakage detector as claimed in claim 1 and including means for providing guard voltage means to drive guard shields between circuit means connected to said isolated conductors and other components of said leakage detector.
References Cited (Backward Citations)
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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) | 1976-01-09 | 1976-07-10 | 1977-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-09 | 1980-07-10 | 1981-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-09 | 1984-07-10 | 1985-01-09 | $7700.00 | Window Closed / Lapsed |