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).
Test memorandum for a C.C. type car heater No. A.75 and rheostat CT.776/2.
| Identifier | ExFiles\Box 137\2\ scan0021 | |
| Date | 7th February 1938 | |
| 12-7 EWS/JF MEMORANDUM 7th February, 1938. Report dated 5. 2. 38. From RESEARCH DEPT. To L.667. TEST OF C.C. TYPE CAR HEATER NO.A.75 AND RHEOSTAT CT.776/2 AS RETURNED FROM ROLLS ROYCE LTD. Motor number Klaxon E.C.M. 12 volt. Motor tested without any preliminary warming up. | Voltage across circuit. | Volts across Motor. | Volts across Rheostat | Current in circuit | Motor Watts. | Rheostat Watts. | R.P.M. | Stud No. | Remarks. | |---|---|---|---|---|---|---|---|---| | 12 | 4.5 | 7.5 | .946 | 4.25 | 7.1 | 505 | 1 | 7.9 Ohms | | 12 | 5.4 | 6.6 | 1.01 | 5.45 | 6.66 | 725 | 2 | 6.3 " | | 12 | 6.6 | 5.4 | 1.09 | 7.2 | 5.88 | 1330 | 3 | 5 " | | 12 | 7.9 | 4.1 | 1.155 | 9.125 | 4.74 | 1800 | 4 | 3.5 " | | 12 | 9.48 | 2.52 | 1.21 | 11.48 | 3.05 | 2200 | 5 | 2.05 " | Tested after 1/2 hrs. running. | 12 | 9.6 | 2.4 | 1.18 | 11.3 | 2.83 | 2300 | 5 | 2.05 " | | 12 | 8.26 | 3.74 | 1.09 | 9.0 | 4.07 | 1900 | 4 | 3.5 " | | 12 | 7.02 | 4.98 | 1.03 | 7.24 | 5.14 | 1560 | 3 | 5 " | | 12 | 5.95 | 6.05 | .962 | 5.72 | 5.82 | 1200 | 2 | 6.3 " | | 12 | 5.0 | 7.0 | .90 | 4.5 | 6.3 | 885 | 1 | 7.9 " | Motor would start unaided when rheostat was placed on stud number one with 12 volts across the circuit. | ||