Patent US3767946A successfully refreshed from Google Patents.
US3767946A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Junction field effect transistor device for replacing a pentode
Assignee: AT&T Inc
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Filing: 1972-07-17
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Granted: 1973-10-23
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Expires: 1992-07-17
Abstract
Abstract A field-effect transistor device for replacing a pentode includes four terminals which correspond to a cathode terminal, a control grid terminal, a screen grid terminal and a plate terminal of the pentode. When placed into an oscillator circuit to replace the pentode, voltage signals appearing at the terminal corresponding to the control grid terminal of the pentode are utilized by a first transistor circuit to provide feedback signals at the terminal which corresponds to the screen grid terminal of the pentode. The same voltage signals are amplified by a second transistor circuit to supply output signals at the terminal corresponding to the plate terminal of the pentode.
Inventors
- 👤 R Berger
- 👤 A Holt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:15
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/51; H03K17/56; H03K17/567; H03B; H03B5/00; H03B5/30; H03B5/32; H03B5/36; H03B5/364; H03B2200/00; H03B2200/0002; H03B2200/0012
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
152 words
A field-effect transistor device for replacing a vacuum tube having at least a cathode, a control grid, a plate, and a screen grid, the device comprising: a first and a second field-effect transistor circuit, each having a source termination, a gate termination and a drain termination, the source termination of the first circuit being coupled to the source termination of the second circuit and the gate termination of the first circuit being coupled to the gate termination of the second circuit; and means, corresponding to cathode, control gird, plate and screen grid connections of the vacuum tube for connecting the coupled source terminations, the coupled gate terminations, the drain termination of the first circuit and the drain termination of the second circuit to a ground terminal, to a signal voltage terminal, to a positively biased output loop terminal and to a positively biased signal feedback terminal of an external electric circuit, respectively.
Claim 2
Dependent Claim
152 words
A field-effect transistor device for replacing a vacuum tube having at least a cathode, a control grid, a plate, and a screen grid, the device comprising: a first and a second field-effect transistor circuit, each having a source termination, a gate termination and a drain termination, the source termination of the first circuit being coupled to the source termination of the second circuit and the gate termination of the first circuit being coupled to the gate termination of the second circuit; and means, corresponding to cathode, control gird, plate and screen grid connections of the vacuum tube for connecting the coupled source terminations, the coupled gate terminations, the drain termination of the first circuit and the drain termination of the second circuit to a ground terminal, to a signal voltage terminal, to a positively biased output loop terminal and to a positively biased signal feedback terminal of an external electric circuit, respectively.
Claim 3
Dependent Claim
126 words
A device according to claim 1 wherein at least one of the field-effect transistor circuits is a cascoded circuit comprising: a first field-effect transistor having a source, a gate and a drain, the source of the first transistor being coupled to the source termination of thE cascoded circuit and the gate of the first transistor being coupled to the gate termination of the cascoded circuit; and a second field effect transistor having a source, a gate and a drain, the source of the second transistor being coupled to the drain of the first transistor, the gate of the second transistor being coupled to the source of the first transistor and the drain of the second transistor being coupled to the drain termination of the cascoded circuit.
Claim 4
Dependent Claim
27 words
A device according to claim 1 further comprising an impedance coupled between the sources of the transistor circuits and the ground terminal of the external electric circuit.
Claim 5
Dependent Claim
15 words
A device according to claim 3 wherein the impedance is a normally forward biased diode.
Claim 6
Dependent Claim
197 words
A field-effect transistor circuit for replacing the function of a pentode vacuum tube in an oscillator circuit having an oscillator loop, a feedback loop and a common ground return for each loop, the transistor circuit comprising: a first and a second field-effect transistor each having a source, a gate and a drain, the source of the first transistor being coupled to the gate of the second transistor and the drain of the first transistor being coupled to the source of the second transistor; a third field-effect transistor having a source, a gate and a drain, the source of the third transistor being coupled to the source of the first transistor, and the gate of the third transistor being coupled to the gate of the first transistor; and means for coupling the source of the first transistor to the common ground return for each loop, the gate of the first transistor to a terminal in the oscillator loop to receive oscillating voltage signals, the drain of the second transistor to a positively biased point of the output loop and the drain of the third transistor to a positively biased point of the oscillator loop in the oscillator circuit.
Claim 7
Dependent Claim
197 words
A field-effect transistor circuit for replacing the function of a pentode vacuum tube in an oscillator circuit having an oscillator loop, a feedback loop and a common ground return for each loop, the transistor circuit comprising: a first and a second field-effect transistor each having a source, a gate and a drain, the source of the first transistor being coupled to the gate of the second transistor and the drain of the first transistor being coupled to the source of the second transistor; a third field-effect transistor having a source, a gate and a drain, the source of the third transistor being coupled to the source of the first transistor, and the gate of the third transistor being coupled to the gate of the first transistor; and means for coupling the source of the first transistor to the common ground return for each loop, the gate of the first transistor to a terminal in the oscillator loop to receive oscillating voltage signals, the drain of the second transistor to a positively biased point of the output loop and the drain of the third transistor to a positively biased point of the oscillator loop in the oscillator circuit.
Claim 8
Dependent Claim
216 words
A field-effect transistor device for replacing a vacuum tube in a circuit, which comprises: a base; a cathode pin, a control grid pin, a screen grid pin and a plate pin geometrically mounted in the base to correspond to similar positions of contact pins of the tube; the first field-effect transistor having a source, a gate and a drain mounted with respect to the base, the gate of such first transistor being coupled to the control grid pin; a second field-effect transistor having a source, a gate and a drain mounted with respect to the base, the source of the second transistor being coupled to the drain of the first transistor, the gate of the second transistor being coupled to the source of the first transistor and the drain of the second transistor being coupled to the plate pin; a third field-effect transistor having a source, a gate and a drain mounted with respect to the base, the source of the third transistor being coupled to the source of the first transistor, the gate of the third transistor being coupled to the control grid pin and the drain of the third transistor being coupled to the screen grid pin; and an impedance coupled between the sources of the first and third transistors and the cathode pin.
Claim 9
Dependent Claim
216 words
A field-effect transistor device for replacing a vacuum tube in a circuit, which comprises: a base; a cathode pin, a control grid pin, a screen grid pin and a plate pin geometrically mounted in the base to correspond to similar positions of contact pins of the tube; the first field-effect transistor having a source, a gate and a drain mounted with respect to the base, the gate of such first transistor being coupled to the control grid pin; a second field-effect transistor having a source, a gate and a drain mounted with respect to the base, the source of the second transistor being coupled to the drain of the first transistor, the gate of the second transistor being coupled to the source of the first transistor and the drain of the second transistor being coupled to the plate pin; a third field-effect transistor having a source, a gate and a drain mounted with respect to the base, the source of the third transistor being coupled to the source of the first transistor, the gate of the third transistor being coupled to the control grid pin and the drain of the third transistor being coupled to the screen grid pin; and an impedance coupled between the sources of the first and third transistors and the cathode pin.
Claim 10
Dependent Claim
14 words
A device according to claim 6 wherein the impedance comprises a forward biased diode.
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) | 1976-10-22 | 1977-04-23 | 1977-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-22 | 1981-04-23 | 1981-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-22 | 1985-04-23 | 1985-10-23 | $7700.00 | Window Closed / Lapsed |