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 results for determining the optimal brush position on a 20 hp dynamo with a 48 coil armature.
| Identifier | ExFiles\Box 165\6\ img224 | |
| Date | 9th December 1924 | |
| RR 239 (150 BKS.) (DB{Donald Bastow - Suspensions} 461-B 12-24)*MP 306975 Y 6003 ROLLS-ROYCE LTD. INSTRUCTIONS. To: E.F.C. Order No: AD 45 Customer's No.: X6003 Date: 9. Dec. 1924 20 hp Dynamo with 48 Coil Armature Brush position determination Tests have now been made on dynamo N with the above armature. Brush positions ranging from 3 1/2° advance to 13 1/2° retard were tried the best all round results being at about 7 1/2°. This position gives a cutting in speed of 810 rpm, a peak output of 14.0 amperes at about 1770 rpm and an output of a little over 7.0 amperes at 4000 rpm as shown on attached curve. The Commutation is good at this position and incidentally the armature gives this setting in a standard carcase without further alteration. Signed: [illegible signature] This Sheet must be filed on completion of the work. | ||