US3590356A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light sensitive servomotor control circuit
Assignee: Bendix Corp
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Filing: 1969-02-17
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Granted: 1971-06-29
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Expires: 1989-02-17
Abstract
Abstract A light sensitive control circuit for a voltage sensitive motor is described. The circuit includes two light sensitive elements which receive equal amounts of light when an element which is controlled by the circuit is positioned properly. Undesired movement of the element results in changes in the light received by the light sensitive elements thereby resulting in a loss of their equality. The diodes form a part of a balanced circuit, across which the motor is connected. In the balanced position, both sides of the motor are at the same potential and it remains stationary. When the control circuit becomes unbalanced in response to changes in the light sensitive elements, the motor is connected across a potential difference and rotates in a direction dictated by the direction of the potential difference. Rotation of the motor corrects the position of the element under control and simultaneously equalizes the light impinging upon the light sensitive elements and thereby rebalances the control circuit.
Inventors
- 👤 Laurence C Hofmeister
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:13
CPC Classifications
G; G05; G05D; G05D1/00; G05D1/08; G05D1/0808; G05D1/0816; G05D3/00; G05D3/12; G05D3/14; G05D3/1409; G05D3/1472
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
313 words
An electrical circuit for receiving an input signal indicative of the spatial orientation of a mechanical member and yielding an output signal for causing said mechanical member to maintain a desired spatial orientation, said circuit being connected between a source of operating voltage and ground, said circuit comprising: two current paths connected in parallel between said source of operating voltage and ground, each said current path including a photosensitive element and first and second transistor amplifiers, each said transistor amplifier having a control input terminal; an electric motor connected mechanically to said mechanical member and connected electrically between the junctions of said first and second amplifiers in each of said two current paths, whereby said motor will move in direction and amount according to the unbalance in current flowing in said current paths, positive feedback means for increasing the sensitivity of said circuit to unbalance of current in said current paths whereby an increase in current in one of said paths causes reduction of current in the order of said paths and vice versa; and means for varying an electrical parameter of said photosensitive elements to cause unbalance of current in said paths, including: a plurality of light sources, each said light source illuminating one said photosensitive element, a ligHt filter, said light filter being interposed between said light sources and said photosensitive elements, the opacity of said light filter varying along a linear dimension of said filter, said filter being mechanically connected to said mechanical member, said filter being moved along said linear dimension by movement of said mechanical member, whereby movement of said mechanical member from said desired orientation causes said filter to so move that said light sources illuminate said photosensitive elements unequally thereby unbalancing the currents in said two current paths and causing said motor to move in direction and amount to restore said member to said desired orientation.
Claim 2
Dependent Claim
313 words
An electrical circuit for receiving an input signal indicative of the spatial orientation of a mechanical member and yielding an output signal for causing said mechanical member to maintain a desired spatial orientation, said circuit being connected between a source of operating voltage and ground, said circuit comprising: two current paths connected in parallel between said source of operating voltage and ground, each said current path including a photosensitive element and first and second transistor amplifiers, each said transistor amplifier having a control input terminal; an electric motor connected mechanically to said mechanical member and connected electrically between the junctions of said first and second amplifiers in each of said two current paths, whereby said motor will move in direction and amount according to the unbalance in current flowing in said current paths, positive feedback means for increasing the sensitivity of said circuit to unbalance of current in said current paths whereby an increase in current in one of said paths causes reduction of current in the order of said paths and vice versa; and means for varying an electrical parameter of said photosensitive elements to cause unbalance of current in said paths, including: a plurality of light sources, each said light source illuminating one said photosensitive element, a ligHt filter, said light filter being interposed between said light sources and said photosensitive elements, the opacity of said light filter varying along a linear dimension of said filter, said filter being mechanically connected to said mechanical member, said filter being moved along said linear dimension by movement of said mechanical member, whereby movement of said mechanical member from said desired orientation causes said filter to so move that said light sources illuminate said photosensitive elements unequally thereby unbalancing the currents in said two current paths and causing said motor to move in direction and amount to restore said member to said desired orientation.
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) | 1974-06-28 | 1974-12-28 | 1975-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-28 | 1978-12-28 | 1979-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-28 | 1982-12-28 | 1983-06-29 | $7700.00 | Window Closed / Lapsed |