Patent US3582981A successfully refreshed from Google Patents.
US3582981A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solenoid driver circuit
Assignee: AT&T Inc
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Filing: 1969-03-18
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Granted: 1971-06-01
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Expires: 1989-03-18
Abstract
Abstract A circuit for operating and holding a solenoid in response to an applied signal includes two transistor switches. The first switch closes a path between a capacitor and the solenoid coil to attain a voltage level necessary to operate the solenoid. The second switch closes a path between the capacitor and ground discharging the capacitor thereby decreasing the voltage applied to the coil after a predetermined time to a lower level required during the hold condition.
Inventors
- 👤 Stephen A Dalyai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:19
CPC Classifications
H; H01; H01H; H01H47/00; H01H47/02; H01H47/04; H01H47/043; H03; H03K; H03K17/00; H03K17/51; H03K17/56; H03K17/60; H03K17/64
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
122 words
Apparatus for operating a solenoid in response to an externally applied signal comprising: a solenoid coil having first and second terminals, a voltage source having first and second terminals, said voltage source first terminal being connected to said solenoid coil first terminal, a capacitor having first and second terminals, means for charging said capacitor by establishing a charging path from said voltage source first terminal through said capacitor to said voltage source second terminal, first and second transistor switches responsive to said externally applied signal for simultaneously connecting said capacitor second terminal to said solenoid coil second terminal and said capacitor first terminal to said voltage source second terminal, and means responsive to said second transistor switch for interrupting said charging path.
Claim 2
Dependent Claim
122 words
Apparatus for operating a solenoid in response to an externally applied signal comprising: a solenoid coil having first and second terminals, a voltage source having first and second terminals, said voltage source first terminal being connected to said solenoid coil first terminal, a capacitor having first and second terminals, means for charging said capacitor by establishing a charging path from said voltage source first terminal through said capacitor to said voltage source second terminal, first and second transistor switches responsive to said externally applied signal for simultaneously connecting said capacitor second terminal to said solenoid coil second terminal and said capacitor first terminal to said voltage source second terminal, and means responsive to said second transistor switch for interrupting said charging path.
Claim 3
Dependent Claim
138 words
In combination in a solenoid driver circuit: an inductive coil having two terminals, a source of direct current voltage having a reference terminal and a voltage level terminal, said voltage level terminal being connected to a first of said two coil terminals, a storage capacitor having first and second output terminals, means connecting said storage capacitor first terminal to said voltage source voltage level terminal and means connecting said storage capacitor second terminal to said voltage source reference terminal for charging said capacitor, switching means responsive to external stimuli for simultaneously connecting said capacitor second output terminal to the second of said two coil terminals and said capacitor first output terminal to said voltage source reference terminal, and means responsive to said external stimuli for disconnecting said storage capacitor second output terminal from said voltage source reference terminal.
Claim 4
Dependent Claim
138 words
In combination in a solenoid driver circuit: an inductive coil having two terminals, a source of direct current voltage having a reference terminal and a voltage level terminal, said voltage level terminal being connected to a first of said two coil terminals, a storage capacitor having first and second output terminals, means connecting said storage capacitor first terminal to said voltage source voltage level terminal and means connecting said storage capacitor second terminal to said voltage source reference terminal for charging said capacitor, switching means responsive to external stimuli for simultaneously connecting said capacitor second output terminal to the second of said two coil terminals and said capacitor first output terminal to said voltage source reference terminal, and means responsive to said external stimuli for disconnecting said storage capacitor second output terminal from said voltage source reference terminal.
Claim 5
Dependent Claim
41 words
A combination in accordance with claim 2 wherein said means connecting said storage capacitor first terminal to said voltage source reference terminal includes a diode poled to conduct current from said storage capacitor second terminal to said voltage source reference terminal.
Claim 6
Dependent Claim
48 words
A combination in accordance with claim 2 wherein said switching means includes a first transistor having base, collector and emitter electrodes, said first transistor collector electrode being connected to said storage capacitor first terminal and said first transistor emitter electrode being connected to said voltage source reference terminal.
Claim 7
Dependent Claim
51 words
A combination in accordance with claim 4 wherein said switching means further includes a second transistor having base, emitter and collector electrodes, said second transistor collector electrode being connected to the second of said two coil terminals and said second transistor emitter terminal being connected to said storage capacitor second terminal.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-31 | 1974-11-30 | 1975-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-31 | 1978-11-30 | 1979-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-31 | 1982-11-30 | 1983-06-01 | $7700.00 | Window Closed / Lapsed |