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 detailing the particulars of two types of 12-volt chassis dynamos.
| Identifier | ExFiles\Box 3\5\ 05-page147 | |
| Date | 14th January 1920 | |
| X.295 14.1.20. X.295 - PARTICULARS OF SMITH (T & M) 12 VOLT CHASSIS DYNAMOS. Type A.{Mr Adams} Type 2D. Carcase. Material I. Wt. I Wt or S.M. Length 6.75 6.75 Diameter 5.69 5.80 Thickness .375 .400 Armature. Diameter 3.15 3.15 Active Length 3.70 3.775 No. of slots 19 19 Resistance (cold) .685 w .61 w Commutator. Diameter 2" 2.05" Useful length .90 1.00" No. of segments. 38 38 Brushes. Material C.M.6 Morganite. E.G.3 Morganite. Bearing surface (width) .375" .375" " (length) .75" .75" Number per holder. 1 1 Field Winding. Resistance (cold) approx) 4 w 4.1 w Weight of complete machine (includes cradle) 36.75 lbs. 36.5 Rated output (4.75 lbs) 12 amps. 12 amps. Speed for 12.4 volts (cold) 500 430 " " 13.6 volts (hor) 585 500 Max: output (hot) 13.4 amps. 12.5 | ||