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).
Coil temperature increases using different ballast resistances and the potential detrimental effects.
| Identifier | ExFiles\Box 69\1\ scan0179 | |
| Date | 17th October 1928 | |
| RR 23B (150 BKS.) (DB{Donald Bastow - Suspensions} 461-B 12 24) MP 306975 ROLLS-ROYCE, LTD. INSTRUCTIONS. (2) To Order No. (WD{Mr Wood/Mr Whitehead} 28 contd) Customer's No. being approx. 16°C. Corresponding temperatures using a double value ballast resistance are approx 45°C and 55°C. In the maximum (running) temperature condition the increase in coil temperature using the 1 1/2 ballast is 11°C, and as a maximum car temperature figure of 120°C was obtained with a double ballast (see WD{Mr Wood/Mr Whitehead}15/17-10-28) this increase would we consider be detrimental to the life of the coil in its present position on the S.S. and Phantom. Further tests of course are necessary to be able to finally confirm this. Signed H & W. This Sheet must be filed on completion of the work. | ||