US3673480A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit for operating polyphase induction motors from single phase supply
Assignee: Individual
•
Filing: 1970-10-26
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Granted: 1972-06-27
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Expires: 1990-10-26
Abstract
Abstract A circuit for providing the phased currents necessary for starting and operating polyphase motors from a single phase voltage supply. Out of phase currents are obtained by connecting a capacitor to one or more of the motor windings. Upon the motors'' reaching nearly full speed, a potential voltage relay operates to remove the capacitor from the motor circuit. Chatter of the potential voltage relay is avoided by inclusion in the circuit of a series resistor which is selectively shorted by a further relay connected in parallel with the starting capacitor.
Inventors
- 👤 Colin G Johnstone
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:25
CPC Classifications
H; H02; H02P; H02P1/00; H02P1/16; H02P1/26
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
106 words
In a circuit for operating a polyphase induction motor from a single phase voltage supply, the combination comprising, a series connection of a first relay coil means, a first contact means controlled thereby and an induction motor starting capacitor, means connected in parallel with said induction motor starting capacitor for reducing a charge stored thereon, means for applying a single phase voltage across said series connection, and, means for supplying inputs to a polyphase induction motor, consisting of first and second input means connected to said single phase applying means and third input means connected between said first relay coil means and said first contact means.
Claim 2
Dependent Claim
106 words
In a circuit for operating a polyphase induction motor from a single phase voltage supply, the combination comprising, a series connection of a first relay coil means, a first contact means controlled thereby and an induction motor starting capacitor, means connected in parallel with said induction motor starting capacitor for reducing a charge stored thereon, means for applying a single phase voltage across said series connection, and, means for supplying inputs to a polyphase induction motor, consisting of first and second input means connected to said single phase applying means and third input means connected between said first relay coil means and said first contact means.
Claim 3
Dependent Claim
15 words
The circuit of claim 1, wherein said series connection further comprises a variable impedance means.
Claim 4
Dependent Claim
18 words
The circuit of claim 1, wherein, said first contact means are normally closed, thereby completing said series circuit.
Claim 5
Dependent Claim
30 words
The circuit of claim 2, wherein, said charge reducing means is connected to vary said variable impedance in response to the value of voltage on said induction motor starting capacitor.
Claim 6
Dependent Claim
22 words
The circuit of claim 1, further comprising means for visually indicating the presence of a charge on said induction motor starting capacitor.
Claim 7
Dependent Claim
22 words
The circuit of claim 5, wherein said indicating means comprises a neon bulb connected in parallel with said induction motor starting capacitor.
Claim 8
Dependent Claim
41 words
The circuit of claim 2, wherein said variable impedance means comprises a resistor with a second relay contact means connected in parallel therewith, and said charge reducing means comprises a second relay coil means for controlling said second relay contact means.
Claim 9
Dependent Claim
14 words
The circuit of claim 7, wherein said second relay contact means is normally open.
Claim 10
Dependent Claim
32 words
The circuit of claim 1, wherein said induction motor starting capacitor comprises a plurality of capacitors so arranged that they may be connected in series, parallel or singly in said series circuit.
Claim 11
Dependent Claim
82 words
In a circuit for operating a polyphase induction motor from a single phase voltage supply, first and second relay coil means connected in series by a first relay contact means operated by said first coil means, variable impedance means connected in series with said first relay coil means, capacitor means connected in parallel across said second relay coil means by second relay contact means operated by said second coil means, and means for applying a single phase voltage across said series connection.
Claim 12
Dependent Claim
82 words
In a circuit for operating a polyphase induction motor from a single phase voltage supply, first and second relay coil means connected in series by a first relay contact means operated by said first coil means, variable impedance means connected in series with said first relay coil means, capacitor means connected in parallel across said second relay coil means by second relay contact means operated by said second coil means, and means for applying a single phase voltage across said series connection.
Claim 13
Dependent Claim
45 words
The circuit of claim 10, further comprising means for supplying inpuTs to a three phase motor, consisting of first and second input means connected to said single phase applying means, and third input means connected between said first coil means and said first contact means.
Claim 14
Dependent Claim
21 words
The circuit of claim 10, further comprising means connected in parallel with said capacitor means for reducing a charge stored thereon.
Claim 15
Dependent Claim
14 words
The circuit of claim 12, wherein said charge reducing means comprises a resistor means.
Claim 16
Dependent Claim
30 words
The circuit of claim 13, wherein said variable impedance means comprises a resistor with a third relay contact means connected in parallel therewith and controlled by said second coil means.
Claim 17
Dependent Claim
23 words
The circuit of claim 14, wherein said first contact means is normally closed and said second and third contact means are normally open.
Claim 18
Dependent Claim
71 words
The circuit of claim 10, further comprising means for supplying inputs to a three phase motor, consisting of first and second input means connected to said single phase applying means, and third input means connected between said first coil means and said first contact means, and wherein said variable impedance means comprises a resistor with a third relay contact means connected in parallel therewith and controlled by said second coil means.
References Cited (Backward Citations)
US2832925A
Cited
US3122693A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |