Electrical resistors
Abstract
Abstract ELECTRICAL PRECISION RESISTORS HAVING A CERAMIC FORMER ARE PROVIDED WITH A RESISTANCE FILM OF A NICKEL-PHOSPHOROUS ALLOY WITH AN ELECTRICAL SURFACE RESISTANCE VALUE BETWEEN 0.5 OHM TO 500 KILOHMS PER SQUARE, THE ALLOY CONTAINING FROM 5 TO 16% BY WEIGHT OF PHOSPHORUS, THE THICKNESS OF THE FILM VARYING FROM 220 A. TO 25,000 A. AND THE ROOTMEAN-SQUARE DEVIATION OF FILM THICKNESS BETWEEN DIFFERENT SAMPLE OF AREA WITH A DIMENSION GREATER THAN 0.01 X 0.01 CM. IS AT MOST 8% OF THE MEAN THICKNESS AT THE LOWEST ELECTRICAL RESISTANCE VALUE AND AT MOST 4% AT THE HIGHEST ELECTRICAL RESISTANCE VALUE; THE MANUFACTURE OF THESE RESISTORS IS EFFECTED BATCH-WISE BY A MEHTOD INVOLVING REACTIVATING A CATALYTIC PALLADIUM LAYER, BEFORE ELECTROLESSLY DEPOSITING THE NICKEL-PHOSPHORUS FILM WHILE TUMBLING THE RESISTORS IN THE PLATING SOLUTION, BY WASHING WITH A REACTIVATING SOLUTION CONTAINING HYPOPHOSPHITE AND NICKEL IONS, AND THE DEPOSITED NICKEL-PHOSPHORUS FILM IS STABILIZED BY HEATING IN AIR A TEMPERATURE OF FROM 100 TO 400*C.
Inventors
- 👤 James Edge
Bibliographic Details
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-03 | 1974-11-02 | 1975-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-03 | 1978-11-02 | 1979-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-03 | 1982-11-02 | 1983-05-04 | $7700.00 | Window Closed / Lapsed |