US3679873A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stabilizing circuit for anticipating controller
Assignee: Monsanto Co
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Filing: 1971-01-11
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Granted: 1972-07-25
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Expires: 1991-01-11
Abstract
Abstract An SCR is supplied with quick-acting positive feedback bias to insure reliable turn-on. A slower acting negative feedback bias then turns the SCR off. The positive feedback bias makes the circuit less sensitive to variations among SCR''s and other circuit components.
Inventors
- 👤 John R Bray
- 👤 Perry F Mckinney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:31
CPC Classifications
G; G05; G05D; G05D23/00; G05D23/19; G05D23/20; G05D23/24; G05D23/1906; G05D23/1909
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
158 words
Circuitry comprising in combination: a. an A.C. energized solid state switching device having input and output circuits; b. means in said output circuit for energizing a load upon conduction by said switching device; c. said input circuit comprising, serially connected: 1. a signal source; 2. a first negative feedback network producing when energized a first bias voltage tending to oppose conduction of said switching device, said first bias voltage increasing at a relatively slow nonlinear rate toward a given first limiting value; 3. a second positive feedback network producing when energized a second bias voltage tending to enhance conduction of said switching device, said second bias voltage increasing at a relatively fast nonlinear rate toward a limiting value less than said first given value, whereby the resultant feedback bias voltage first enhances and then opposes conduction of said switching device; d. each of said first and second networks being energized during the period when said load is energized.
Claim 2
Dependent Claim
158 words
Circuitry comprising in combination: a. an A.C. energized solid state switching device having input and output circuits; b. means in said output circuit for energizing a load upon conduction by said switching device; c. said input circuit comprising, serially connected: 1. a signal source; 2. a first negative feedback network producing when energized a first bias voltage tending to oppose conduction of said switching device, said first bias voltage increasing at a relatively slow nonlinear rate toward a given first limiting value; 3. a second positive feedback network producing when energized a second bias voltage tending to enhance conduction of said switching device, said second bias voltage increasing at a relatively fast nonlinear rate toward a limiting value less than said first given value, whereby the resultant feedback bias voltage first enhances and then opposes conduction of said switching device; d. each of said first and second networks being energized during the period when said load is energized.
Claim 3
Dependent Claim
23 words
The circuitry defined in claim 1, wherein said signal source includes means for generating a signal related to the temperature of said load.
Claim 4
Dependent Claim
37 words
a first negative feedback network producing when energized a first bias voltage tending to oppose conduction of said switching device, said first bias voltage increasing at a relatively slow nonlinear rate toward a given first limiting value;
Claim 5
Dependent Claim
37 words
a first negative feedback network producing when energized a first bias voltage tending to oppose conduction of said switching device, said first bias voltage increasing at a relatively slow nonlinear rate toward a given first limiting value;
Claim 6
Dependent Claim
75 words
a second positive feedback network producing when energized a second bias voltage tending to enhance conduction of said switching device, said second bias voltage increasing at a relatively fast nonlinear rate toward a limiting value less than said first given value, whereby the resultant feedback bias voltage first enhances and then opposes conduction of said switching device; d. each of said first and second networks being energized during the period when said load is energized.
Claim 7
Dependent Claim
75 words
a second positive feedback network producing when energized a second bias voltage tending to enhance conduction of said switching device, said second bias voltage increasing at a relatively fast nonlinear rate toward a limiting value less than said first given value, whereby the resultant feedback bias voltage first enhances and then opposes conduction of said switching device; d. each of said first and second networks being energized during the period when said load is energized.
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) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |