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 and results for coil temperature tests comparing an old standard single ballast with the present standard ballast.
| Identifier | ExFiles\Box 69\1\ scan0247 | |
| Date | 24th October 1929 | |
| RR 238 (150 BKS.) (DB{Donald Bastow - Suspensions} 461-B-12-24) MP 306975 X. 8710 ROLLS-ROYCE LTD. INSTRUCTIONS. To: E.7.C. Order No. WD{Mr Wood/Mr Whitehead}86 Customer's No. X8710 Coil temperature tests Further to WD{Mr Wood/Mr Whitehead}80/10-10-29 we have conducted similar tests with another standard 22 SWG primary coil using an old standard single ballast resistance. The temperatures attained were:- after test ① 207°C after test ② 158°C as compared with 197°C and 136°C using the present standard ballast. Upon unwinding the coil the primary was found to be OK only discoloured brown. This proves that the old arrangement of single ballast + 22 SWG coil is OK. Signed: H E.{Mr Elliott - Chief Engineer} W. This Sheet must be filed on completion of the work. | ||