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).
Comparison of Phantom III and Bentley dynamos, discussing regulator failures and statistics.
| Identifier | ExFiles\Box 168a\3\ img458 | |
| Date | 2nd February 1938 | |
| CHILDS To-Dr. & Rm.{William Robotham - Chief Engineer}... from RHC{R. H. Coverley - Production Engineer}/Smd.{J. Smedley} 6142 RHC{R. H. Coverley - Production Engineer}/Smd.{J. Smedley}1/LS.2.2.38. PHANTOM III. DYNAMO. With reference to Rm.{William Robotham - Chief Engineer}7/R.26.1.38, we note that some further information is necessary to explain paragraph 1 in the memo RHC{R. H. Coverley - Production Engineer}/Smd.{J. Smedley}1/LS.17.1.38, which refers to regulator failure and the disparity between the Bentley and Phantom Chassis. The two machines in question have different characteristics as follows :- Bentley - 20 amps. - 13 volts - 940 r.p.m. Phantom - 20 amps. - 13 volts - 620 r.p.m. Also, we have reason to believe the battery output is greater on the Phantom III than the Bentley. The Regulator does appear to be working more within a reliable limit on the 25/30-HP. and Bentley dynamo, than on the Phantom III so that if the Regulator does stick momentarily the consequences are not so troublesome. A demonstration of this can be seen at any time on the bench test rig, for instance, if a Regulator be attached to the 25/30-HP. and Bentley machine very little sparking at the brushes is noticed. On the other hand, a Phantom III machine (which works perfectly with a resistance in circuit) sparks very badly when the Regulator is substituted. Also, we find the following statistics of Regulators returned to Derby interesting. FAULTY REGULATORS RECEIVED AT DERBY DURING DECEMBER & JANUARY. BENTLEY. 3 - Low Output. 2 - Sticking. PHANTOM III. 4 - Low Output. 3 - Sticking. 2 - Erratic. -cont'd- | ||