US3732484A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Delayed action load switch
Assignee: MC WILKER ENTERPRISES
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Filing: 1971-10-20
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Granted: 1973-05-08
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Expires: 1991-10-20
Abstract
Abstract A delayed-action load switch for A-C operation including a trigger-controlled bilateral solid-state power switch, e.g., a triac, connected in series with a load, and in parallel with a manually-operable on-off switch across an A-C source. A chargestorage capacitor discharges through a bilateral breakover device (e.g., an avalanche switch) to trigger the triac to conduction when the charge on the capacitor reaches a threshold value. The capacitor is charged on each cycle from the A-C source through a bias accumulation network which builds up a D-C potential, increasing with each cycle in opposing the charging of the capacitor so that the threshold value is attained progressively later in each cycle and the proportion of the cycle during which the triac is conductive is gradually reduced to zero.
Inventors
- 👤 J Mckenna
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:03
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/28; H03K17/292
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
125 words
An electronic load switch comprising, in combination, input terminals for connection in series to an A-C source; a triggered bilateral power switching means having a pair of terminal electrodes, connected respectively to said input terminals, and a control electrode; a bridge rectifier having one input terminal connected to one of said load switch input terminals; a storage capacitor having one terminal connected to the other input terminal of said bridge rectifier and its other terminal to the other load switch input terminal; an avalanche switch connected between said one terminal of the storage capacitor and the control terminal of said power switching means; and a bias accumulator capacitor of much higher capacitance than said storage capacitor, connected across the output terminals of said bridge rectifier.
Claim 2
Dependent Claim
125 words
An electronic load switch comprising, in combination, input terminals for connection in series to an A-C source; a triggered bilateral power switching means having a pair of terminal electrodes, connected respectively to said input terminals, and a control electrode; a bridge rectifier having one input terminal connected to one of said load switch input terminals; a storage capacitor having one terminal connected to the other input terminal of said bridge rectifier and its other terminal to the other load switch input terminal; an avalanche switch connected between said one terminal of the storage capacitor and the control terminal of said power switching means; and a bias accumulator capacitor of much higher capacitance than said storage capacitor, connected across the output terminals of said bridge rectifier.
Claim 3
Dependent Claim
38 words
An electronic load switch according to claim 1 including a pair of diodes connected cathode-to-cathode in series with a capacitor between said one input terminal of the bridge rectifier and said other input terminal of the load switch.
Claim 4
Dependent Claim
45 words
An electronic load switch according to claim 2 including a double pole single throw switch having one pair of switch terminals in common with the load switch input terminals and another pair of switch terminals connected respectively to the output terminals of said bridge rectifier.
Claim 5
Dependent Claim
43 words
An electronic load switch according to claim 3 including a resistance element connected between said one input terminal of the load switch and said one input terminal of the bridge rectifier, said resistance element and storage capacitor constituting a small RC time constant.
References Cited (Backward Citations)
US3596171A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-07 | 1976-11-06 | 1977-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-07 | 1980-11-06 | 1981-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-07 | 1984-11-06 | 1985-05-08 | $7700.00 | Window Closed / Lapsed |