US4964014A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solenoid valve driver
Assignee: Deere and Co
•
Filing: 1989-01-06
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Granted: 1990-10-16
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Expires: 2009-01-06
Abstract
Abstract A solenoid current control system includes a microprocessor which periodically generates a desired peak current value and which energizes the solenoid coil. Current through the coil is sensed via a series resistor and the sensed current is compared to the desired peak current by comparator. The comparator generates an interrupt signal when the sensed current reaches the desired peak value. The interrupt signal is applied to the microprocessor which responds by de-energizing the coil.
Inventors
- 👤 Thomas E. Boe
- 👤 Vijay M. Dharia
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 08:04
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/20; H; H01; H01F; H01F7/00; H01F7/06; H01F7/08; H01F7/18; H01F7/1844; F02D2041/2017
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
102 words
A system for controlling an electrical current applied to a coil of a solenoid, comprising: means for periodically energizing the coil; means for sensing actual current through the coil; means for generating a reference current value corresponding to a desired peak coil current; means for comparing the actual current to the reference current value and for generating a first signal when the actual current reaches the reference current value; means for periodically de-energizing the coil in response to generation of the first signal; and means for reducing the reference current value if no first signal is generated within a certain time period.
Claim 2
Independent Claim
102 words
A system for controlling an electrical current applied to a coil of a solenoid, comprising: means for periodically energizing the coil; means for sensing actual current through the coil; means for generating a reference current value corresponding to a desired peak coil current; means for comparing the actual current to the reference current value and for generating a first signal when the actual current reaches the reference current value; means for periodically de-energizing the coil in response to generation of the first signal; and means for reducing the reference current value if no first signal is generated within a certain time period.
Claim 3
Dependent Claim
32 words
The current control system of claim 1, further comprising: means for generating a second signal if actual coil current does not reach the reduced reference current value within a predetermined time period.
Claim 4
Independent Claim
111 words
A system for controlling an electrical current applied to a coil of a solenoid, comprising: means for periodically energizing the coil; means for sensing actual current through the coil; means for generating a reference current value corresponding to a desired peak coil current; means for comparing the actual current to the reference current value and for generating a first signal when the actual current reaches the reference current value; means for periodically de-energizing the coil in response to generation of the first signal; and means for re-energizing the coil a predetermined time after the de-energization of the coil, wherein the predetermined time decreases as a function of increasing reference current value.
Claim 5
Independent Claim
111 words
A system for controlling an electrical current applied to a coil of a solenoid, comprising: means for periodically energizing the coil; means for sensing actual current through the coil; means for generating a reference current value corresponding to a desired peak coil current; means for comparing the actual current to the reference current value and for generating a first signal when the actual current reaches the reference current value; means for periodically de-energizing the coil in response to generation of the first signal; and means for re-energizing the coil a predetermined time after the de-energization of the coil, wherein the predetermined time decreases as a function of increasing reference current value.
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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) | 1993-10-15 | 1994-04-16 | 1994-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-10-15 | 1998-04-16 | 1998-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-10-15 | 2002-04-16 | 2002-10-16 | $7700.00 | Window Closed / Lapsed |