US3202922A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transistor chopper
Assignee: Gevaert Photo Producten NV
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Filing: 1961-04-03
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Granted: 1965-08-24
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Expires: 1981-04-03
Abstract
No abstract record available.
Inventors
- 👤 Schamphelaere Lucien Amede De
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:14
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/38; H03F3/387
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
196 words
A TRANSISTOR CHOPPER DIRECT CURRENT AMPLIFIER OF THE FEEDBACK COMPENSATION TYPE FOR AMPLIFYING SMALL INPUT VOLTAGES, COMPRISING: (A) A CHOPPER TRANSISTOR HAVING ITS EMITTER-COLLECTOR PATH CONNECTED IN SERIES WITH A COMPENSATION RESISTOR AND THE SOURCE OF SIGNALS TO BE AMPLIFIED, (B) AN ALTERNATING CURRENT AMPLIFIER HAVING ITS INPUT TERMINALS CONNECTED ACROSS THE EMITTER-COLLECTOR PATH OF SAID TRANSISTOR FOR PERIODIC SHORT-CIRCUITING THEREBY, (C) A PHASE-SENSITIVE DEMODULATOR HAVING ITS SIGNAL INPUT CONNECTED TO THE OUTPUT OF SAID AMPLIFIER, AND HAVING ITS OUTPUT CONNECTED SERIALLY THROUGH A LOAD IMPEDANCE AND SAID COMPENSATION RESISTOR, TO DEVELOP ACROSS THE LATTER A FEEDBACK VOLTAGE, IN SERIES WITH THE SIGNALS TO BE AMPLIFIED, FOR DIFFERENCE COMPARISON THEREWITH, (D) A SQUARE-WAVE GENERATOR CONNECTED TO SUPPLY A REFERENCE SIGNAL TO SAID DEMODULATOR, AND (E) MEANS FOR APPLYING THE OUTPUT VOLTAGE OF SAID SQUARE-WAVE GENERATOR BETWEEN THE BASE ELECTRODE OF SAID CHOPPER TRANSISTOR AND ONE OTHER ELECTRODE THEREOF, SAID MEANS COMPRISING A DIODE CHARACTERIZED BY FORWARD CONDUCTIVITY ONLY FOR APPLIED VOLTAGES GREATER THAN THE LOWEST POTENTIAL DIFFERENCE BETWEEN SAID GENERATOR AND SAID OTHER ELECTRODE OF THE TRANSISTOR; WHEREBY THE BASE VOLTAGE OF SAID TRANSISTOR IS DRIVEN TO A ZERO VALUE DURING ALTERNATE HALF-CYCLES OF SAID GENERATOR.
Claim 2
Dependent Claim
196 words
A TRANSISTOR CHOPPER DIRECT CURRENT AMPLIFIER OF THE FEEDBACK COMPENSATION TYPE FOR AMPLIFYING SMALL INPUT VOLTAGES, COMPRISING: (A) A CHOPPER TRANSISTOR HAVING ITS EMITTER-COLLECTOR PATH CONNECTED IN SERIES WITH A COMPENSATION RESISTOR AND THE SOURCE OF SIGNALS TO BE AMPLIFIED, (B) AN ALTERNATING CURRENT AMPLIFIER HAVING ITS INPUT TERMINALS CONNECTED ACROSS THE EMITTER-COLLECTOR PATH OF SAID TRANSISTOR FOR PERIODIC SHORT-CIRCUITING THEREBY, (C) A PHASE-SENSITIVE DEMODULATOR HAVING ITS SIGNAL INPUT CONNECTED TO THE OUTPUT OF SAID AMPLIFIER, AND HAVING ITS OUTPUT CONNECTED SERIALLY THROUGH A LOAD IMPEDANCE AND SAID COMPENSATION RESISTOR, TO DEVELOP ACROSS THE LATTER A FEEDBACK VOLTAGE, IN SERIES WITH THE SIGNALS TO BE AMPLIFIED, FOR DIFFERENCE COMPARISON THEREWITH, (D) A SQUARE-WAVE GENERATOR CONNECTED TO SUPPLY A REFERENCE SIGNAL TO SAID DEMODULATOR, AND (E) MEANS FOR APPLYING THE OUTPUT VOLTAGE OF SAID SQUARE-WAVE GENERATOR BETWEEN THE BASE ELECTRODE OF SAID CHOPPER TRANSISTOR AND ONE OTHER ELECTRODE THEREOF, SAID MEANS COMPRISING A DIODE CHARACTERIZED BY FORWARD CONDUCTIVITY ONLY FOR APPLIED VOLTAGES GREATER THAN THE LOWEST POTENTIAL DIFFERENCE BETWEEN SAID GENERATOR AND SAID OTHER ELECTRODE OF THE TRANSISTOR; WHEREBY THE BASE VOLTAGE OF SAID TRANSISTOR IS DRIVEN TO A ZERO VALUE DURING ALTERNATE HALF-CYCLES OF SAID GENERATOR.
References Cited (Backward Citations)
US3003122A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-08-23 | 1969-02-22 | 1969-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-08-23 | 1973-02-22 | 1973-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-08-23 | 1977-02-22 | 1977-08-24 | $7700.00 | Window Closed / Lapsed |