Patent US3857070A successfully refreshed from Google Patents.
US3857070A
Expired / Lapsed
US
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Single-lamp ground detector for converter-inverter power supplies
Assignee: United States Atomic Energy Commission
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Filing: 1973-09-07
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Granted: 1974-12-24
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Expires: 1993-09-07
Abstract
Abstract A single-lamp ground detector is used in a converter-inverter power supply system. In can sense grounds on any one of the three busses, AC input, DC link and AC output.
Inventors
- 👤 J Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 03:45
CPC Classifications
H; H02; H02H; H02H7/00; H02H7/10; H02H7/12; H02H7/1216
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
156 words
A ground detector system for a converter-inverter power supply comprising an AC input converter section, a DC link with a positive and negative line and an AC output inverter section in combination with a fault detecting circuit on the DC link, said fault detecting circuit being connected between the positive and negative lines and comprising a ground detector two-position switch in series with a lamp and a tapped resistor, the ground detector switch having a Lamp Test position connected to the positive line and a Ground Detect position connected to the sole ground, the tapped end of the resistor connected to a common point of two series resistors which are connected between the positive and negative lines, the switch providing that the lamp will light only if there is a fault or non-infinite resistance to ground in one of the AC input lines, AC output lines or DC link when the Ground Detect position is actuated.
Claim 2
Dependent Claim
156 words
A ground detector system for a converter-inverter power supply comprising an AC input converter section, a DC link with a positive and negative line and an AC output inverter section in combination with a fault detecting circuit on the DC link, said fault detecting circuit being connected between the positive and negative lines and comprising a ground detector two-position switch in series with a lamp and a tapped resistor, the ground detector switch having a Lamp Test position connected to the positive line and a Ground Detect position connected to the sole ground, the tapped end of the resistor connected to a common point of two series resistors which are connected between the positive and negative lines, the switch providing that the lamp will light only if there is a fault or non-infinite resistance to ground in one of the AC input lines, AC output lines or DC link when the Ground Detect position is actuated.
Claim 3
Dependent Claim
37 words
The ground detector system of claim 1 wherein a fault in the positive or negative line of the DC link will cause a flow of direct current through the lamp when the Ground Detect position is actuated.
Claim 4
Dependent Claim
33 words
The ground detector system of claim 1 wherein a fault in the AC input lines will cause the lamp to be energized by a staircase current when the Ground Detect position is activated.
Claim 5
Dependent Claim
34 words
The ground detector system of claim 1 wherein a fault in the AC output lines will cause the lamp to be energized by a square wave current when the Ground Detect position is actuated.
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) | 1977-12-23 | 1978-06-24 | 1978-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-23 | 1982-06-24 | 1982-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-23 | 1986-06-24 | 1986-12-24 | $7700.00 | Window Closed / Lapsed |