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).
Letter from AC-Sphinx Sparking Plug Co. Ltd. detailing the test results for high and slow speed heater motors.
| Identifier | ExFiles\Box 137\2\ scan0210 | |
| Date | 9th November 1938 | |
| File Heading general 1158 AC-SPHINX SPARKING PLUG Co. LTD. DIRECTORS: N.F. Stockbridge, W.O.Kennington, C.J.Bartlett. Telegrams: SPHINX, DUNSTABLE. DUNSTABLE, BEDS., ENGLAND. Telephone: DUNSTABLE 360. Our Ref. DBB/DJG Your Ref. 9th November, 1938. Messrs. Rolls-Royce, Ltd., DERBY. For the Attention of Mr. C. S. Steadman. Dear Sirs, We are dispatching to you today two of the special Heater installations ordered to your Drawing No. SCD.938 and our Experimental No. E/CH-115. These Heaters include one high speed and one slow speed motor, and there still remains to be dispatched to you one of the slow speed motors, which we have not yet received. The standard speed motor will be given our Experimental No. E/CH-116 and will in addition be marked with the No. ENH.859. The slow speed motor will have our Experimental No. E/CH-117 and will additionally be marked ENH.858. We have tested these motors both on our standard test paddle, blueprint of which we enclose, and upon one of the fans included with these assemblies, with the following results:- High Speed Motor. Volts. Amps. R.P.M. With Paddle 10 2.15 2060 12 2.5 2400 14 2.9 2700 With Fan. 10 2.15 2140 12 2.45 2500 14 2.75 2780 Slow Speed Motor. Volts. Amps. R.P.M. With Paddle 10 1.6 1780 12 1.85 2150 14 2.1 2440 With Fan. 10 1.6 1825 12 1.8 2180 14 2.05 2480 AC Air Cleaners - AC Clocks - AC Fuel Pumps - AC Oil Filters - AC Oil Gauges - AC Plugs - AC Speedometers - AC Windscreen Wipers. | ||