Patent US4578596A successfully refreshed from Google Patents.
US4578596A
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Circuit arrangement for driving a thyristor with a phototransistor
Assignee: Siemens AG
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Filing: 1984-10-24
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Granted: 1986-03-25
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Expires: 2004-10-24
Abstract
Abstract In a circuit arrangement for drive of a thyristor with a phototransistor, the collector-emitter path of the phototransistor is between one of two alternating voltage terminals and a gate terminal of the thyristor. In order to prevent an activation of the unilluminated phototransistor due to a steep voltage edge (dv/dt) load), its base current given such a load is carried off via an IGFET of the enhancement type. This IGFET is controlled by an IGFET of the depletion type acting as a current source which lies between a gate terminal and source terminal of the enhancement type IGFET. A capacitor is connected in series with the depletion-type IGFET. This series connection lies between the two alternating voltage terminals.
Inventors
- 👤 Jenoe Tihanyi
- 👤 Christine Fellinger
- 👤 Ludwig Leipold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:56
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/51; H03K17/78; H03K17/79; H03K17/08; H03K17/082; H03K17/0826; H10; H10F; H10F39/00; H10F39/10; H10F39/103
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
146 words
A circuit arrangement for driving at least one thyristor connected to an alternating voltage from a phototransistor, comprising: (a) a phototransistor connected to drive the thyristor connected to an alternating voltage; (b) an emitter-collector path of said phototransistor connected between a first of two alternating voltage terminals and a gate terminal of said thyristor; (c) a drain-source path of an enhancement type IGFET connected between a base terminal of said phototransistor and a second of said two alternating voltage terminals; (d) a drain-source path of a depletion type IGFET connected between a gate terminal and a source terminal of said enhancement type IGFET; (e) a gate terminal of said depletion type IGFET and a source terminal thereof being electrically connected to said second alternating voltage terminal; and (f) a capacitor connected between the drain terminal of said depletion type IGFET and said first alternating voltage terminal.
Claim 2
Dependent Claim
146 words
A circuit arrangement for driving at least one thyristor connected to an alternating voltage from a phototransistor, comprising: (a) a phototransistor connected to drive the thyristor connected to an alternating voltage; (b) an emitter-collector path of said phototransistor connected between a first of two alternating voltage terminals and a gate terminal of said thyristor; (c) a drain-source path of an enhancement type IGFET connected between a base terminal of said phototransistor and a second of said two alternating voltage terminals; (d) a drain-source path of a depletion type IGFET connected between a gate terminal and a source terminal of said enhancement type IGFET; (e) a gate terminal of said depletion type IGFET and a source terminal thereof being electrically connected to said second alternating voltage terminal; and (f) a capacitor connected between the drain terminal of said depletion type IGFET and said first alternating voltage terminal.
Claim 3
Dependent Claim
22 words
A circuit arrangement of claim 1 wherein said second alternating voltage terminal is electrically connected to a cathode terminal of said thyristor.
Claim 4
Dependent Claim
25 words
A circuit arrangement of claim 1 wherein a Zener diode is connected between the gate terminal of said enhancement-type IGFET and the source terminal thereof.
Claim 5
Dependent Claim
45 words
A circuit arrangement of claim 1 wherein a diode is connected between an anode terminal of said thyristor and said first alternating voltage terminal, said diode being poled such that it is reverse biased when voltage in a non-conducting direction is fed to said thyristor.
Claim 6
Dependent Claim
103 words
A circuit arrangement for driving at least one thyristor connected to an alternating voltage from a phototransistor, comprising: a phototransistor having its collector connected to a first alternating voltage terminal and its emitter available for driving a thyristor; a first IGFET having its drain-source path connected between a base of the phototransistor and a second alternating voltage terminal; a second IGFET having its drain-source path connected between a gate of the first IGFET and the second alternating voltage terminal, its gate being connected to its source; and a capacitor connecting between the first alternating voltage terminal and the gate of the first IGFET.
Claim 7
Dependent Claim
103 words
A circuit arrangement for driving at least one thyristor connected to an alternating voltage from a phototransistor, comprising: a phototransistor having its collector connected to a first alternating voltage terminal and its emitter available for driving a thyristor; a first IGFET having its drain-source path connected between a base of the phototransistor and a second alternating voltage terminal; a second IGFET having its drain-source path connected between a gate of the first IGFET and the second alternating voltage terminal, its gate being connected to its source; and a capacitor connecting between the first alternating voltage terminal and the gate of the first IGFET.
Claim 8
Dependent Claim
38 words
A circuit arrangement according to claim 5 wherein an anode of the thyristor connects through a diode to the first terminal, its cathode connects to a second terminal, and its gate connects to the emitter of the phototransistor.
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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) | 1989-03-24 | 1989-09-23 | 1990-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-24 | 1993-09-23 | 1994-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-24 | 1997-09-23 | 1998-03-25 | $7700.00 | Window Closed / Lapsed |