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).
Specification sheet comparing Type A and Type 3A Smith (T & M) 12 Volt chassis dynamos.
| Identifier | ExFiles\Box 3\5\ 05-page235 | |
| Date | 12th May 1919 | |
| K.295.-PARTICULARS OF SMITH (T & M) 12 VOLT CHASSIS DYNAMOS. Type A.{Mr Adams} Type 3A. Carcass. Material I.C. I.C. Length 5.75 5.50 Diameter 5.89 5.89 Thickness .375 .375 Armature. Diameter 3.195 3.195 Active length 3.8970 2.50 No. of slots 19 19 Resistance (cold) .685w .618w Commutator. Diameter 2" 1.81" Useful length .90 .90 No. of segments 38 38 Brushes. Material CM6 Morganite CM9 Morganite Bearing surface (width) .375" .375" " " (length) .75" .75" Number per holder 1 1 Field Winding. Resistance (cold) (approx.) 4w 7.75w Weight of complete machine 36.75 lbs. 30.0 lbs. (includes cradle) Rated Output 12 amps. 10 amps. 4.75 cl. Speed for 12.4 volts (cold) 500 640 " " 13.6 volts (hot) 585 1735 Max. output (hot) 13.4 amps 9.4 amps | ||