US3852646A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solenoid drive circuit
Assignee: Design Elements Inc
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Filing: 1970-12-28
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Granted: 1974-12-03
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Expires: 1990-12-28
Abstract
Abstract A circuit for initially applying an unusually large drive voltage to a solenoid coil and for subsequently reducing the applied voltage during the travel of the solenoid plunger. The solenoid coil is serially connected to a first transistor circuit operating as an on-off switch and to a second transistor circuit connected parallel to the first transistor circuit and operating to variably control the voltage applied to the solenoid. A capacitor-charge timing circuit controls the variable transistor and thereby gradually reduces the voltage applied to the solenoid.
Inventors
- 👤 E Mason
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:01
CPC Classifications
H; H01; H01H; H01H47/00; H01H47/02; H01H47/04; H03; H03K; H03K17/00; H03K17/51; H03K17/56; H03K17/60; H03K17/64
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
209 words
A solenoid drive circuit for energizing and de-energizing a solenoid in response to suitable signals at a drive circuit input, said circuit comprising: a. a first electronic switch means in series with said solenoid and a source of driving power for switching a current through said solenoid, the first switch means having a control input connected to and being controlled at said drive circuit input; b. an electronic valve means connected parallel to said first switch means for providing a time changing current through said solenoid, the valve means having a control input; c. a timing means for providing a time changing current for controlling said valve means and comprising serially connected timing resistance, capacitance and a diode connected to permit current flow in a direction to turn on said valve means and to charge said capacitance, said timing means connected between the control input of the valve means and said drive circuit input; and d. capacitance discharge means for at times discharging the capacitance and comprising a second electronic switch means connected to discharge said capacitance when turned on and a second diode connected in series with the second electronic switch means and said capacitance in a polarity to be reverse biased except during discharge of the capacitance.
Claim 2
Dependent Claim
209 words
A solenoid drive circuit for energizing and de-energizing a solenoid in response to suitable signals at a drive circuit input, said circuit comprising: a. a first electronic switch means in series with said solenoid and a source of driving power for switching a current through said solenoid, the first switch means having a control input connected to and being controlled at said drive circuit input; b. an electronic valve means connected parallel to said first switch means for providing a time changing current through said solenoid, the valve means having a control input; c. a timing means for providing a time changing current for controlling said valve means and comprising serially connected timing resistance, capacitance and a diode connected to permit current flow in a direction to turn on said valve means and to charge said capacitance, said timing means connected between the control input of the valve means and said drive circuit input; and d. capacitance discharge means for at times discharging the capacitance and comprising a second electronic switch means connected to discharge said capacitance when turned on and a second diode connected in series with the second electronic switch means and said capacitance in a polarity to be reverse biased except during discharge of the capacitance.
Claim 3
Dependent Claim
41 words
A drive circuit according to claim 1 wherein: said first electronic switch means includes a bipolar junction transistor and said valve means includes a bipolar junction transistor having timing circuit charging current flowing through the base-emitter junction of the valve means.
Claim 4
Dependent Claim
51 words
A drive circuit according to claim 2 wherein: the capacitance and diode share a common node and said second electronic switch means is a bipolar junction transistor having its emitter connected to said common node, its base connected to said drive circuit input, And its collector connected to said second diode.
Claim 5
Dependent Claim
71 words
A drive circuit according to claim 2 wherein: said valve means comprises a first transistor in an emitter follower configuration and a second bipolar junction transistor connected to the output of the emitter follower, and the emitter follower is connected to the logic level power supply and said second transistor and said first electronic switch are NPN devices and are the only transistors subject to collector voltages above the logic level.
Claim 6
Dependent Claim
64 words
A drive circuit according to claim 4 wherein: said second electronic switch is a PNP junction transistor having its emitter connected between the first diode and the capacitance, having its base connected to the drive circuit input and having its collector connected to the anode of said second diode, the cathode of said second diode being connected to the opposite side of said capacitance.
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) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |