US3555360A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Phase controlled ground fault circuit interrupter
Assignee: Hubbell Inc
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Filing: 1969-03-20
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Granted: 1971-01-12
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Expires: 1989-03-20
Abstract
Abstract A ground fault circuit interrupter of the type which includes a differential transformer having a toroidal core, two identical primary windings of opposing polarity, and a secondary winding. In this invention, a biasing winding is also added to the core which normally opposes one primary winding and aids the other. During normal operation, the biasing winding induces a voltage in the secondary winding which keeps the load circuit breaker closed. The circuit breaker opens when the secondary voltage drips below an established minimum value.
Inventors
- 👤 Sung Chuel Lee
- 👤 Clifford E Brockway
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 19:29
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/26; H02H3/32; H02H3/33; H02H3/331
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
132 words
A ground fault circuit interrupter which comprises: first and second conductors connectable between a power supply and a load; a closed magnetic core; a first primary winding on said core in series with said first conductor; a second primary winding on said core in series with said second conductor, the magnetic flux produced in said core by said second winding substantially canceling the flux produced by said first winding when the currents in said conductors are equal; a biasing winding on said core connected across said first and second conductors; a secondary winding on said core; circuit breaker means in one of said conductors; and sensing circuit means responsive to the voltage induced in said secondary winding for maintaining said circuit breaker means closed when said voltage exceeds a preselected minimum value.
Claim 2
Dependent Claim
132 words
A ground fault circuit interrupter which comprises: first and second conductors connectable between a power supply and a load; a closed magnetic core; a first primary winding on said core in series with said first conductor; a second primary winding on said core in series with said second conductor, the magnetic flux produced in said core by said second winding substantially canceling the flux produced by said first winding when the currents in said conductors are equal; a biasing winding on said core connected across said first and second conductors; a secondary winding on said core; circuit breaker means in one of said conductors; and sensing circuit means responsive to the voltage induced in said secondary winding for maintaining said circuit breaker means closed when said voltage exceeds a preselected minimum value.
Claim 3
Dependent Claim
16 words
The interrupter of claim 1 further including means for controlling current flow through said biasing winding.
Claim 4
Dependent Claim
13 words
The interrupter of claim 2 wherein said current control means is a rheostat.
Claim 5
Dependent Claim
55 words
The interrupter of claim 1 wherein said sensing circuit means comprises: solid state switching means connected between said first and second conductors; means for triggering said switching means into its conductive state when the induced secondary voltage exceeds said preselected minimum value; and circuit breaker coil means responsive to current flow through said switching means.
Claim 6
Dependent Claim
16 words
The interrupter of claim 4 wherein said coil means is in series with said switching means.
Claim 7
Dependent Claim
44 words
The interrupter of claim 4 wherein second solid state switching means is connected between said first and second conductors and is triggered into its conductive state when the other switching means becomes nonconductive, said coil means being in series with said second switching means.
Claim 8
Dependent Claim
23 words
The interrupter of claim 4 wherein said switching means is a controlled rectifier having its gate and cathode connected across said secondary winding.
Claim 9
Dependent Claim
21 words
The interrupter of claim 7 wherein an avalanche diode is in series between said secondary winding and said gate. second winding
Claim 10
Dependent Claim
16 words
The interrupter of claim 1 further including means for rectifying the output of said secondary winding.
Claim 11
Dependent Claim
148 words
A ground fault circuit interrupter which comprises: first and second conductors connectable between a power supply and a load; a first primary winding on said core in series with said first conductor; a second primary winding on said core in series with said second conductor, the magnetic flux produced in said core by said second winding substantially canceling the flux produced by said first winding when the currents in said conductors are equal; a biasing winding on said core connected across said first and second conductors; a rheostat in series with said biasing winding; a circuit breaker operating coil; a controlled rectifier having its anode-cathode circuit in series with said operating coil across said first and second conductors and its gatE-cathode circuit across said secondary winding; an avalanche diode in series with the gate of said controlled rectifier; and means for rectifying the output of said secondary winding.
Claim 12
Dependent Claim
148 words
A ground fault circuit interrupter which comprises: first and second conductors connectable between a power supply and a load; a first primary winding on said core in series with said first conductor; a second primary winding on said core in series with said second conductor, the magnetic flux produced in said core by said second winding substantially canceling the flux produced by said first winding when the currents in said conductors are equal; a biasing winding on said core connected across said first and second conductors; a rheostat in series with said biasing winding; a circuit breaker operating coil; a controlled rectifier having its anode-cathode circuit in series with said operating coil across said first and second conductors and its gatE-cathode circuit across said secondary winding; an avalanche diode in series with the gate of said controlled rectifier; and means for rectifying the output of said secondary winding.
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) | 1974-01-11 | 1974-07-13 | 1975-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-11 | 1978-07-13 | 1979-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-11 | 1982-07-13 | 1983-01-12 | $7700.00 | Window Closed / Lapsed |