US3564293A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature-compensating thyristor control
Assignee: POWER SEMICONDUCTORS Inc
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Filing: 1968-04-16
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Granted: 1971-02-16
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Expires: 1988-04-16
Abstract
Abstract A temperature-sensing element is mounted in good heat transfer relation with a thyristor, and is connected to a control winding of the thyristor firing control circuit. When the temperature of the thyristor rises too high for existing operating conditions the sensing element is effective to reduce the current flow in the thyristor, without stooping it altogether. A signal derived from the current flow through the thyristor may be combined with a signal from the temperature-sensing means to provide a control more accurately representative of the junction temperature in the thyristor. The control is continuous over a predetermined temperature range.
Inventors
- 👤 John E Mungenast
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:57
CPC Classifications
H; H02; H02H; H02H7/00; H02H7/20; H02H7/205
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
173 words
In a control circuit comprising a semiconductor switching device operating in on and off conditions, and means operatively connected to said switching device and effective to produce a control signal for controlling the relative time durations of said on and off conditions of said switching device; the improvement which comprises means operatively connected to said switching device for sensing the temperature thereof, and means connecting said temperature-sensing means and said control signal-producing means and effective, as the sensed temperature of said switching device increases and decreases within a predetermined temperature range, to substantially continuously respectively decrease and increase the time duration of said on condition relative to the time duration of said off condition, and further comprising means for sensing the current flowing through said switching device and means operatively connecting said current sensing means and said signal producing means and effective as the sensed current increases and decreases to correspondingly act to respectively decrease and increase the time duration of said on condition relative to the time duration of said off condition.
Claim 2
Dependent Claim
173 words
In a control circuit comprising a semiconductor switching device operating in on and off conditions, and means operatively connected to said switching device and effective to produce a control signal for controlling the relative time durations of said on and off conditions of said switching device; the improvement which comprises means operatively connected to said switching device for sensing the temperature thereof, and means connecting said temperature-sensing means and said control signal-producing means and effective, as the sensed temperature of said switching device increases and decreases within a predetermined temperature range, to substantially continuously respectively decrease and increase the time duration of said on condition relative to the time duration of said off condition, and further comprising means for sensing the current flowing through said switching device and means operatively connecting said current sensing means and said signal producing means and effective as the sensed current increases and decreases to correspondingly act to respectively decrease and increase the time duration of said on condition relative to the time duration of said off condition.
Claim 3
Dependent Claim
31 words
The circuit of claim 1, in which said switching device is a thyristor having a gate electrode, said control signal from said signal producing means being coupled to said gate electrode.
Claim 4
Dependent Claim
47 words
The circuit of claim 2, in which said current-sensing means comprises a light source electrically connected to said thyristor so as to be energized by the output therefrom, and photosensitive means in light communication with said light source and electrically connected to said control signal producing means.
Claim 5
Dependent Claim
56 words
The circuit of claim 2, in which said current-sensing means comprises resistor means electrically connected to said thyristor so as to be energized by the output therefrom, means operatively connected to said resistor means for sensing the temperature thereof and producing a signal corresponding thereto, and means connecting said signal to said control signal producing means.
Claim 6
Dependent Claim
51 words
In the control circuit of claim 4, means for sensing the ambient temperature and producing a signal corresponding thereto, means for comparing said ambient temperature signal with said resistor means temperature signal and produCing a resultant signal, it being said resultant signal which is connected to said control signal producing means.
Claim 7
Dependent Claim
49 words
In the control circuit of claim 1, in which said current-sensing means comprises a light source electrically connected to said switching device so as to energized by the output therefrom, and photosensitive means in light communication with said light source and electrically connected to said control signal producing means.
Claim 8
Dependent Claim
58 words
The control circuit of claim 1, in which said current-sensing means comprises resistor means electrically connected to said switching device so as to be energized by the output therefrom, means operatively connected to said resistor means for sensing the temperature thereof and producing a signal corresponding thereto, and means connecting said signal to said control signal producing means.
Claim 9
Dependent Claim
52 words
In the control circuit of claim 1, means for sensing the ambient temperature and producing a signal corresponding thereto, means for comparing a said ambient temperature signal with said resistor means temperature signal and producing a resultant signal, it being said resultant signal which is connected to said control signal producing means.
Claim 10
Dependent Claim
15 words
In the control circuit of claim 1, in which said temperature-sensing means comprises a thermistor.
Claim 11
Dependent Claim
31 words
In the control circuit of claim 1, in which said signal-producing means comprises saturable reactor means comprising control winding means, said temperature-sensing means being operatively connected to said control winding means.
Claim 12
Dependent Claim
24 words
In the control circuit of claim 1, further comprising means operatively connected to said signal-producing means for indicating the magnitude of said control signal.
Claim 13
Dependent Claim
26 words
The control circuit of claim 1, in which the magnitude of the control effect of said current-sensing means is less than that of said temperature means.
Claim 14
Dependent Claim
26 words
The control circuit of claim 2, in which the magnitude of the control effect of said current-sensing means is less than that of said temperature-sensing means.
References Cited (Backward Citations)
US2998547A
Cited
US3293533A
Cited
US3183425A
Cited
US3249929A
Cited
US3278823A
Cited
US3225280A
Cited
US3252010A
Cited
US3296515A
Cited
US3371231A
Cited
US3421027A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-15 | 1974-08-17 | 1975-02-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-15 | 1978-08-17 | 1979-02-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-15 | 1982-08-17 | 1983-02-16 | $7700.00 | Window Closed / Lapsed |