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).
Analysis and comparison of C.A.V., Lucas, and Smith lighting dynamos.
| Identifier | ExFiles\Box 3\5\ 05-page100 | |
| Date | 13th August 1919 | |
| Contd. -7- (a) As a plain shunt machine (Both control brushes removed). (b) One control brush removed. (c) Correctly connected. (d) Control brushes connected to main brushes through equal resistances of such value as to cause half of the armature only to carry current at 3000 R.P.M. i.e. to cause equality of all brush currents. CUT-OUT. Volts on shunt coil to cause cut in at 20° C = 12.2 Amperes = .115 (resistance 106w) Volts to allow contacts to drop apart = 9.95 Amperes = .094 Reverse amps. through series coil to allow contacts to fall apart when 12.2 volts are applied to shunt coil = 1.60 Series coil volts = .029 We attach table of analysis of results of tests of C.A.V., Lucas and Smith lighting dynamos. The Smith dynamo has four brushes as against three (sets) on the Lucas, but is simpler in switching and wiring as it only requires three conductors to be brought away from it as against four for Lucas. For a given out-put at high speeds, it has a much better low speed performance than Lucas, with only a slight additional weight (3 lbs). Contd. | ||