Patent US3503331A successfully refreshed from Google Patents.
Patent US3702435A successfully refreshed from Google Patents.
US3702435A
Expired / Lapsed
US
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Electric power control device
Assignee: Mitsubishi Electric Corp
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Filing: 1971-01-27
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Granted: 1972-11-07
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Expires: 1991-01-27
Abstract
Abstract The disclosed electric power control device utilizes a semiconductor control device and a capacitor. The capacitor is so arranged to be charged during a voltage in the reverse direction applied to the semiconductor control device, and to discharge through a control electrode of the control device when the forward voltage applied to the semiconductor control device is zero or when the voltage exhibits reverse polarity, thereby to switch the semiconductor control device at a zero crossing point of the a.c. voltage from the source.
Inventors
- 👤 Yoshitaka Endo
- 👤 Katsumi Tomiyama
- 👤 Yasushi Takanashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:48
CPC Classifications
G; G05; G05D; G05D23/00; G05D23/19; G05D23/20; G05D23/24; G05D23/1906; G05D23/1909
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
121 words
An electric power control device comprising, a semiconductor control device connected between an a.c. power source and a load and having a control electrode, a first capacitor connected in parallel with said semiconductor control device and charged during a period of time during which an a.c. voltage from the a.c. power source exhibits a reverse polarity with respect to said semiconductor control device, a variable impedance element, a second capacitor connected to the power source through said variable impedance element, a switching element, a discharge circuit for the first capacitor connected to said control electrode of said semiconductor control device through said switching element, and another discharge circuit for the second capacitor connected between said second capacitor and said switching element.
Claim 2
Dependent Claim
121 words
An electric power control device comprising, a semiconductor control device connected between an a.c. power source and a load and having a control electrode, a first capacitor connected in parallel with said semiconductor control device and charged during a period of time during which an a.c. voltage from the a.c. power source exhibits a reverse polarity with respect to said semiconductor control device, a variable impedance element, a second capacitor connected to the power source through said variable impedance element, a switching element, a discharge circuit for the first capacitor connected to said control electrode of said semiconductor control device through said switching element, and another discharge circuit for the second capacitor connected between said second capacitor and said switching element.
Claim 3
Dependent Claim
70 words
An electric power control device as claimed in claim 1, wherein said variable impedance element is a heating element comprising a heating wire, a signal line and a thermosensitive layer exhibiting an impedance of a negative resistance-to-temperature coefficient and sandwiched between the heating wire and the signal line, said heating wire being connected in series with said semiconductor control device and said signal line being connected to said second capacitor.
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) | 1975-11-07 | 1976-05-08 | 1976-11-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-07 | 1980-05-08 | 1980-11-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-07 | 1984-05-08 | 1984-11-07 | $7700.00 | Window Closed / Lapsed |