US4206394A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Motor control circuit
Assignee: Braun GmbH
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Filing: 1978-06-21
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Granted: 1980-06-03
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Expires: 1998-06-21
Abstract
Abstract A motor control circuit of the Wheatstone bridge type is described for driving a direct current motor, selectively, in one direction or the other for the general purpose of automatically setting the diaphragm of a photographic camera in accordance with the light impinging on a photo-responsive element.
Inventors
- 👤 Robert Flandorfer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:19
CPC Classifications
H; H02; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/285; H02P7/288; H02P7/2885
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
151 words
In a control circuit for the bidirectional actuation of a d.c. motor that is coupled to a positioning element, including a d.c. voltage source, a bridge circuit comprising at least two transistors in a push-pull circuit arrangement, a voltage dividing means for said source, a first sensor (2) responsive to the position of said positioning element (35) and connected to an input of said bridge circuit, the improvement which comprises a feedback network including (a second sensor (28) responsive to the current through said d.c. motor and connected to an input of said push-pull circuit such that it tends to increase the voltage fed to the d.c. motor whenever the load of the same is increased, and a negative feedback network (18) leading from the output of the push-pull circuit to an input of said bridge circuit and dimensioned such that the internal resistance of said push-pull circuit is substantially reduced.)
Claim 2
Dependent Claim
151 words
In a control circuit for the bidirectional actuation of a d.c. motor that is coupled to a positioning element, including a d.c. voltage source, a bridge circuit comprising at least two transistors in a push-pull circuit arrangement, a voltage dividing means for said source, a first sensor (2) responsive to the position of said positioning element (35) and connected to an input of said bridge circuit, the improvement which comprises a feedback network including (a second sensor (28) responsive to the current through said d.c. motor and connected to an input of said push-pull circuit such that it tends to increase the voltage fed to the d.c. motor whenever the load of the same is increased, and a negative feedback network (18) leading from the output of the push-pull circuit to an input of said bridge circuit and dimensioned such that the internal resistance of said push-pull circuit is substantially reduced.)
Claim 3
Dependent Claim
43 words
A control circuit in accordance with claim 1 wherein said voltage dividing means comprises a pair of resistors in series between terminals of said supply source and a transistor push-pull circuit including a negative feedback loop reducing the internal resistance of said circuit.
Claim 4
Dependent Claim
23 words
A control circuit as claimed in claim 2 wherein said negative feedback loop in said second push-pull circuit incorporates an operational amplifier (31).
References Cited (Backward Citations)
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US3260912A
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US3427520A
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US3477004A
Cited
US3652913A
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US3809981A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-06-03 | 1983-12-03 | 1984-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-06-03 | 1987-12-03 | 1988-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-06-03 | 1991-12-03 | 1992-06-03 | $7700.00 | Window Closed / Lapsed |