Patent US3668557A successfully refreshed from Google Patents.
US3668557A
Expired / Lapsed
US
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Low frequency blocking oscillator
Assignee: United States Department of the Navy
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Filing: 1970-09-04
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Granted: 1972-06-06
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Expires: 1990-09-04
Abstract
Abstract A low frequency astable blocking oscillator composed of a transistor with a first transformer winding in the collector circuit and a second transformer winding in the base circuit to provide regenerative feedback between the collector and the base. A capacitor is connected to the transistor and is charged by a constant current source to initiate operation of the blocking oscillator when a predetermined voltage is reached. A voltage breakdown device is coupled to the transistor to raise the voltage required by the capacitor before blocking oscillator action commences thereby providing low frequency operation.
Inventors
- 👤 Charles H Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:05
CPC Classifications
H; H03; H03K; H03K3/00; H03K3/02; H03K3/26; H03K3/30
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
97 words
A low frequency blocking oscillator comprising a transistor having base, emitter and collector electrodes, means for providing regenerative feedback between said collector and base electrodes including a transformer having a first winding connected to said collector electrode and a second winding connected to said base electrode, an avalanche breakdown device connected to said emitter electrode of said transistor for raising the threshold voltage of said transistor, energy storage means connected between said second transformer winding and said breakdown device, and means for charging said energy storage means to said raised threshold voltage to initiate operation of transistor.
Claim 2
Dependent Claim
97 words
A low frequency blocking oscillator comprising a transistor having base, emitter and collector electrodes, means for providing regenerative feedback between said collector and base electrodes including a transformer having a first winding connected to said collector electrode and a second winding connected to said base electrode, an avalanche breakdown device connected to said emitter electrode of said transistor for raising the threshold voltage of said transistor, energy storage means connected between said second transformer winding and said breakdown device, and means for charging said energy storage means to said raised threshold voltage to initiate operation of transistor.
Claim 3
Dependent Claim
40 words
A low frequency blocking oscillator according to claim 1 wherein said energy storage means is a capacitor, and said means for charging said energy storage means is a constant current source connected to said capacitor and said first transformer winding.
Claim 4
Dependent Claim
47 words
A low frequency blocking oscillator according to claim 2 wherein said constant current source comprises a transistor having its collector connected to said second transformer winding and said capacitor, and having its base connected to a voltage divider including a diode a voltage divider and a diode.
Claim 5
Dependent Claim
35 words
A low frequency blocking oscillator according to claim 3 further comprising a diode in parallel with said first transformer winding to limit current flyback, and wherein said avalanche breakdown device comprises a silicon unilateral switch.
References Cited (Backward Citations)
US2981898A
Cited
US3292015A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-06 | 1975-12-06 | 1976-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-06 | 1979-12-06 | 1980-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-06 | 1983-12-06 | 1984-06-06 | $7700.00 | Window Closed / Lapsed |