From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Instructions detailing the testing of sparking voltages for two different annular gaps on A.C.
| Identifier | ExFiles\Box 54\3\ Scan240 | |
| Date | 14th August 1924 | |
| RR 238 (180 BKS) (SHDT.29-6-20.) MP 224339 ROLLS-ROYCE LTD. INSTRUCTIONS. To: E.F.B. Order No.: W.A. 68 Customer's No.: X 4645 Sparking voltages of annular gaps on A.C. a.{Mr Adams} Annular gap sent by Mr. Watson of M.L. company. Sparking over voltage = 7925 volts. = 5.25 m.m 3RD point spark gap b. Annular gap sent by Dr. Turner of Lucas company. Sparking over voltage = 8840 volts = 6.5 m.m 3RD point spark gap Width of Gaps:- a.{Mr Adams} 2.75 m.m. b. 3.5 m.m. Signed: H.E.W. This Sheet must be filed on completion of the work. | ||