Patent US2713703A successfully refreshed from Google Patents.
Patent US3678353A successfully refreshed from Google Patents.
US3678353A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic device for electrically braking induction motors, particularly three-phase motors
Assignee: Individual
•
Filing: 1971-03-17
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Granted: 1972-07-18
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Expires: 1991-03-17
Abstract
Abstract A dynamic brake circuit for an a-c motor which includes a single phase a-c circuit connected across two stator terminals of a three phase motor after the motor energizing circuit is opened. A first diode is connected in series with the single phase a-c circuit and the two stator terminals. Two additional diodes are connected from the stator terminal receiving the first diode to the other two stator terminals, respectively, by the device which connects the single phase a-c circuit to the stator terminals.
Inventors
- 👤 Giorgio Marchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:54
CPC Classifications
H; H02; H02P; H02P3/00; H02P3/06; H02P3/18; H02P3/20; H02P3/24
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
259 words
An electric braking system for an induction motor having a stator winding structure, and wherein braking is achieved by means of a braking torque generated by a counter-rotating magnetic field; said system including: an a-c power supply circuit, a single-phase a-c braking current supply circuit, first and second rectifier means each capable of conducting unidirectional current therethrough, first switching means selectively operable for connecting and disconnecting said a-c power supply circuit to said stator winding structure, a first closed circuit including the series connection of said single-phase a-c braking current supply circuit, said first rectifier means, and said stator winding structure, with said first rectifier means being poled to allow unidirectional current flow in said first closed circuit and through said stator winding structure with a given polarity, a second closed circuit including the closed series connection of said second rectifier means and said stator winding structure, with said second rectifier means being poled to allow unidirectional current flow in said second closed circuit and through said stator winding structure with said given polarity, second switching means connected in both said first and second closed cirCuits and operable to close said first and second closed circuits after said first switching means opens, whereby, during motor braking, said first switching means is opened and said switching means is closed so that currents circulate through said stator winding structure the motor rotor, which circulating currents have a magnitude proportional to the speed of the rotor, and build up a counterrotating magnetic field which produces a braking torque for stopping rotor rotation.
Claim 2
Dependent Claim
259 words
An electric braking system for an induction motor having a stator winding structure, and wherein braking is achieved by means of a braking torque generated by a counter-rotating magnetic field; said system including: an a-c power supply circuit, a single-phase a-c braking current supply circuit, first and second rectifier means each capable of conducting unidirectional current therethrough, first switching means selectively operable for connecting and disconnecting said a-c power supply circuit to said stator winding structure, a first closed circuit including the series connection of said single-phase a-c braking current supply circuit, said first rectifier means, and said stator winding structure, with said first rectifier means being poled to allow unidirectional current flow in said first closed circuit and through said stator winding structure with a given polarity, a second closed circuit including the closed series connection of said second rectifier means and said stator winding structure, with said second rectifier means being poled to allow unidirectional current flow in said second closed circuit and through said stator winding structure with said given polarity, second switching means connected in both said first and second closed cirCuits and operable to close said first and second closed circuits after said first switching means opens, whereby, during motor braking, said first switching means is opened and said switching means is closed so that currents circulate through said stator winding structure the motor rotor, which circulating currents have a magnitude proportional to the speed of the rotor, and build up a counterrotating magnetic field which produces a braking torque for stopping rotor rotation.
Claim 3
Dependent Claim
153 words
The braking system of claim 1 wherein said stator winding structure is a multiphase winding having at least first, second and third terminals and wherein said a-c power supply circuit comprises a multiphase a-c source, and wherein said second rectifier means includes a first diode and a second diode, each having anode and cathode electrodes; one of each of said anode or cathode electrodes of said first and second diodes connected to said first and second terminals respectively of said multiphase winding; said first rectifier means having anode and cathode terminals; one of said anode or said cathode electrodes of said first rectifier means connected to said third terminal; the other of said anode or cathode electrodes of said first and second diodes connected to said third terminal; all of the electrodes of said first and second diodes and of said first rectifier means consisting of one of all anodes or all cathodes.
Claim 4
Dependent Claim
172 words
The braking system of claim 1 wherein said stator winding structure is a multiphase winding having at least first, second and third terminals and wherein said a-c power supply circuit comprises a multiphase a-c source, and wherein said second rectifier means includes a first diode and a second diode, each having anode and cathode electrodes; one of each of said anode or cathode electrodes of said first and second diodes connected to said first and second terminals respectively of said multiphase winding; said second rectifier means including third and fourth diodes, each having anode and cathode electrodes; one of each of said anode or cathode electrodes of said third and fourth diodes connected to said first and second terminals of said multiphase winding, whereby either all anodes or all cathodes of said diodes are connected to said first and second terminals; said third terminals and the other of said anode or cathode terminals of said third and fourth diodes being connected to respective terminals of said single-phase a-c braking current supply circuit.
Claim 5
Dependent Claim
74 words
The braking system of claim 1 wherein said stator winding structure is a single-phase winding having first and second terminals; each of said first and second rectifier means having respective anode and cathode electrodes; one of each of either both said anode electrodes or both said cathode electrodes connected to said first terminal; the other of said both anode or both cathode electrodes of said second rectifier means being connected to said second terminal.
Claim 6
Dependent Claim
44 words
The electric braking system of claim 1 wherein said first rectifier means comprises a controlled rectifier having a control electrode, and which further includes control circuit means connected to said control electrode for controlling the conduction of said controlled rectifier in a predetermined manner.
Claim 7
Dependent Claim
44 words
The braking system of claim 2 which further includes transformer means connected between said first and third terminals; and means coupling said transformer means to said second switching means for opening said second switching means when current in said stator winding structure is zero.
Claim 8
Dependent Claim
44 words
The braking system of claim 5 which further includes transformer means connected between said first and third terminals; and means coupling said transformer means to said second switching means for opening said second switching means when current in said stator winding structure is zero.
References Cited (Backward Citations)
US2445430A
Cited
US2818539A
Cited
US2929977A
Cited
US2922097A
Cited
US3209225A
Cited
US3412304A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-18 | 1976-01-17 | 1976-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-18 | 1980-01-17 | 1980-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-18 | 1984-01-17 | 1984-07-18 | $7700.00 | Window Closed / Lapsed |