US4572947A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Triggering method for light triggered thyristors
Assignee: Westinghouse Electric Corp
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Filing: 1984-05-29
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Granted: 1986-02-25
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Expires: 2004-05-29
Abstract
Abstract The present invention provides a method for triggering a light triggered thyristor (LT 2 ) which method comprises using a light source to provide background excitation of carriers in at least the amplifying gate areas of the LT 2 prior to triggering the device. The background excitation is of a low level and will not trigger the device or cause excessive leakage current. At the desired time a second light signal is used to trigger the LT 2 .
Inventors
- 👤 Yu C. Kao
- 👤 Scott G. Leslie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:05
CPC Classifications
H; H10; H10F; H10F30/00; H10F30/20; H10F30/21; H10F30/26; H10F30/263
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
98 words
A method for triggering a light fired thyristor, said light fired thyristor having a photocathode area, an amplifying gate area and a main cathode area, said photocathode area having walls forming an optical well therein, said method comprising exciting carriers in at least the amplifying gate area with light energy, of a predetermined power level, from a first light source, said light energy from said first light source being incapable of triggering the light fired thyristor and thereafter triggering the light fired thyristor by directing light energy from a second light source at at least the optical well.
Claim 2
Independent Claim
98 words
A method for triggering a light fired thyristor, said light fired thyristor having a photocathode area, an amplifying gate area and a main cathode area, said photocathode area having walls forming an optical well therein, said method comprising exciting carriers in at least the amplifying gate area with light energy, of a predetermined power level, from a first light source, said light energy from said first light source being incapable of triggering the light fired thyristor and thereafter triggering the light fired thyristor by directing light energy from a second light source at at least the optical well.
Claim 3
Dependent Claim
26 words
The method of claim 1 in which carriers are excited in the photocathode area and the amplifying gate area by light from the first light source.
Claim 4
Dependent Claim
29 words
The method of claim 1 in which carriers are excited in the photocathode, the amplifying gate area and the main cathode area by light from the first light source.
Claim 5
Dependent Claim
30 words
The method of claim 1 in which the light energy from the first light source is 10%/mm 2 of the minimum light energy required to fire the LT 2 .
Claim 6
Dependent Claim
26 words
The method of claim 1 in which the light energy from the first light source is applied to the light fired thyristor as a constant light.
Claim 7
Dependent Claim
27 words
The method of claim 1 in which the light energy from the first light source is applied to the light fired thyristor in a series of pulses.
References Cited (Backward Citations)
US3459944A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-02-24 | 1989-08-26 | 1990-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-24 | 1993-08-26 | 1994-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-24 | 1997-08-26 | 1998-02-25 | $7700.00 | Window Closed / Lapsed |