Patent US3851235A successfully refreshed from Google Patents.
US3851235A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bridge circuit for controlling a direct current motor
Assignee: Ford Motor Co
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Filing: 1973-12-26
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Granted: 1974-11-26
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Expires: 1993-12-26
Abstract
Abstract A bridge circuit for controlling a direct current motor permits the direction of rotation of the motor to be reversed while permitting the motor speed and its torque or current-level to be separately and independently controlled for each direction of motor rotation. The bridge circuit includes first and second transistors connected in adjacent legs of the bridge circuit and, respectively, first and second circuit means coupled to the first and second transistors for controlling the magnitude of voltage applied to these transistors. The other legs of the bridge circuit include third and fourth transistors. Third and fourth circuit means are coupled, respectively, to the third and fourth transistors for limiting the current which can flow through the third and fourth transistors to respective maximum values. First switching means are provided for controlling the simultaneous application of a control voltage to the first and fourth circuit means, and second switching circuit means are provided for controlling the simultaneous application of a control voltage to the first and fourth circuit means. The winding of the direct current motor is connected across opposite terminals of the bridge circuit.
Inventors
- 👤 C Harrison
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:01
CPC Classifications
H; H02; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/285; H02P7/288
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
363 words
A bridge circuit for the control of a direct current motor, said bridge circuit having first, second, third and fourth terminals, said first and third terminals being voltage supply terminals for connection to a direct current source of electrical energy and said motor having a winding connecting across said second and fourth terminals, said bridge circuit comprising: a. a first transistor having a control electrode and an output circuit, said first transistor output circuit being connected between said first and second terminals; b. a second transistor having a control electrode and an output circuit, said second transistor output circuit being connected between said first and fourth terminals; c. a third transistor having a control electrode and an output circuit, said third transistor output circuit being coupled to said second and third terminals; d. a fourth transistor having a control electrode and an output circuit, said fourth transistor output circuit being coupled to said third and fourth terminals; e. first circuit means for controlling the magnitude of voltage to be applied to said first transistor control electrode and to be applied at said second terminal; f. second circuit means for controlling the magnitude of voltage to be applied to said second transistor control electrode and to be applied at said fourth terminal; g. third circuit means for limiting the current which can flow through said third transistor output circuit to a maximum value, said third circuit means being coupled to said third transistor control electrode; h. fourth circuit means for limiting the current which can flow through said fourth transistor output circuit to a maximum value, said fourth circuit means being coupled to said fourth transistor control electrode; i. first switching circuit means for controlling the simultaneous application of a control voltage to said first and fourth circuit means; and j. second switching circuit means for controlling the simultaneous application of a control voltage to said second and third circuit means; whereby the direction of the current flowing through said motor winding may be controlled, the voltage applied across said motor winding may be controlled to control motor speed and the current flowing through said motor winding may be limited to a maximum value.
Claim 2
Dependent Claim
363 words
A bridge circuit for the control of a direct current motor, said bridge circuit having first, second, third and fourth terminals, said first and third terminals being voltage supply terminals for connection to a direct current source of electrical energy and said motor having a winding connecting across said second and fourth terminals, said bridge circuit comprising: a. a first transistor having a control electrode and an output circuit, said first transistor output circuit being connected between said first and second terminals; b. a second transistor having a control electrode and an output circuit, said second transistor output circuit being connected between said first and fourth terminals; c. a third transistor having a control electrode and an output circuit, said third transistor output circuit being coupled to said second and third terminals; d. a fourth transistor having a control electrode and an output circuit, said fourth transistor output circuit being coupled to said third and fourth terminals; e. first circuit means for controlling the magnitude of voltage to be applied to said first transistor control electrode and to be applied at said second terminal; f. second circuit means for controlling the magnitude of voltage to be applied to said second transistor control electrode and to be applied at said fourth terminal; g. third circuit means for limiting the current which can flow through said third transistor output circuit to a maximum value, said third circuit means being coupled to said third transistor control electrode; h. fourth circuit means for limiting the current which can flow through said fourth transistor output circuit to a maximum value, said fourth circuit means being coupled to said fourth transistor control electrode; i. first switching circuit means for controlling the simultaneous application of a control voltage to said first and fourth circuit means; and j. second switching circuit means for controlling the simultaneous application of a control voltage to said second and third circuit means; whereby the direction of the current flowing through said motor winding may be controlled, the voltage applied across said motor winding may be controlled to control motor speed and the current flowing through said motor winding may be limited to a maximum value.
Claim 3
Dependent Claim
59 words
A bridge circuit for the control of a direct current motor in accordance with claim 1 wherein said first circuit means comprises a potentiometer having a movable arm coupled to said control electrode of said first transistor and wherein said second circuit means comprises a potentiometer having a movable arm coupled to said control electrode of said second transistor.
Claim 4
Dependent Claim
99 words
A bridge circuit for the control of a direct current motor in accordance with claim 1 wherein said third circuit means comprises a potentiometer having a movable arm coupled to said control electrode of said third transistor, wherein said output circuit of said third transistor is coupled to said bridge circuit third terminal through a first resistor, wherein said fourth circuit means comprises a potentiometer having a movable arm, coupled to said control electrode of said fourth transistor, and wherein said output circuit of said fourth transistor is coupled to said bridge circuit third terminal through a second resistor.
Claim 5
Dependent Claim
59 words
A bridge circuit for the control of a direct current motor in accordance with claim 3 wherein said first circuit means comprises a potentiometer having a movable arm coupled to said control electrode of said first transistor and wherein said second circuit means comprises a potentiometer having a movable arm coupled to said control electrode of said second transistor.
Claim 6
Dependent Claim
88 words
A bridge circuit in accordance with claim 1 wherein said third circuit means comprises means for generating a predetermined voltage coupled to said control electrode of said third transistor, wherein said third transistor output circuit is coupled through a first resistor to said bridge circuit third terminal, wherein said fourth circuit means comprises means for generating a predetermined reference voltage coupled to said control electrode of said fourth transistor, and wherein said fourth transistor output circuit is coupled through a second resistor to said bridge circuit third terminal.
Claim 7
Dependent Claim
55 words
A bridge circuit for the control of a direct current motor in accordance with claim 1 wherein said first circuit means is coupled to said control electrode of said first transistor through a first diode and wherein said second circuit means is coupled to said control electrode of said second transistor through a second diode.
Claim 8
Dependent Claim
54 words
A bridge circuit for the control of a direct current motor in accordance with claim 2 wherein said first means is coupled to said control electrode of said first transistor through a first diode and wherein said second circuit means is coupled to said control electrode of said second transistor through a second diode.
Claim 9
Dependent Claim
54 words
A bridge circuit for the control of a direct current motor in accordance with claim 3 wherein said first means is coupled to said control electrode of said first transistor through a first diode and wherein said second circuit means is coupled to said control electrode of said second transistor through a second diode.
Claim 10
Dependent Claim
54 words
A bridge circuit for the control of a direct current motor in accordance with claim 4 wherein said first means is coupled to said control electrode of said first transistor through a first diode and wherein said second circuit means is coupled to said control electrode of said second transistor through a second diode.
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) | 1977-11-25 | 1978-05-27 | 1978-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-25 | 1982-05-27 | 1982-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-25 | 1986-05-27 | 1986-11-26 | $7700.00 | Window Closed / Lapsed |