US3684978A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Capacitor switching arrangement for regulating power output of heating magnetron
Assignee: Fujitsu General Ltd
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Filing: 1970-12-16
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Granted: 1972-08-15
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Expires: 1990-12-16
Abstract
Abstract In a microwave heating apparatus comprising a magnetron, a plurality of capacitors are provided in the high tension rectifier circuit of the magnetron to vary the power output from the magnetron, and are changed over by the same number of switches as the number of the capacitors.
Inventors
- 👤 Tadayasu Otaguro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:31
CPC Classifications
H; H01; H01H; H01H15/00; H01H15/02; H01H15/06; H01H15/08; H01H13/00; H01H13/68; H01H13/70; H01H13/72; H01H13/74; H05; H05B; H05B6/00; H05B6/64; H05B6/6414; H05B6/6417
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
67 words
An output switching device for a microwave heating apparatus including a magnetron, a step-up transformer having a high tension secondary winding, and a rectifier for supplying a rectified high tension to the magnetron; said device comprising a plurality of capacitors, and a capacitance change-over switch for connecting selected one or ones of the capacitors in the high tension rectifier circuit on the secondary side of said transformer.
Claim 2
Dependent Claim
67 words
An output switching device for a microwave heating apparatus including a magnetron, a step-up transformer having a high tension secondary winding, and a rectifier for supplying a rectified high tension to the magnetron; said device comprising a plurality of capacitors, and a capacitance change-over switch for connecting selected one or ones of the capacitors in the high tension rectifier circuit on the secondary side of said transformer.
Claim 3
Dependent Claim
44 words
An output switching device according to claim 1, in which said plurality of capacitors are connected in series relationship to each other in the high tension rectifier circuits, and further including a capacitance change-over switch for shortcircuiting selected one or ones of the capacitors.
Claim 4
Dependent Claim
25 words
An output switching device according to claim 1, in which the capacitors are connected in parallel relationship to each other by said capacitance change-over switch.
Claim 5
Dependent Claim
67 words
An output switching device according to claim 1, further including an electromagnetic contactor having its contacts connected in the primary circuit of the transformer, and a normally closed auxilliary switch connected in the self-holding circuit of the contactor, said auxilliary switch being interlocked with the operation of the capacitance change-over switch in a manner such that the auxilliary switch is opened before the capacitance change-over switch operators.
Claim 6
Dependent Claim
59 words
An output switching device according to claim 4, in which said capacitance change-over switch comprises a push-button switch having detent means which includes a transverse plate capable of transversing motion in response to the operation of the push-button, said transverse plate carrying an operating member which opens the auxilliary switch prior to the operation of the capacitance change-over switch.
Claim 7
Dependent Claim
62 words
An output switching device according to claim 4, further including a first relay responsive to an operating instruction to said capacitance change-over switch for operating the auxilliary switch, a timer energized simultaneously with the first relay for providing a time delay of a predetermined length, and a second relay responsive to the output from the timer for operating said capacitance change-over switch.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-15 | 1976-02-14 | 1976-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-15 | 1980-02-14 | 1980-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-15 | 1984-02-14 | 1984-08-15 | $7700.00 | Window Closed / Lapsed |