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 for a 5-inch dynamo.
| Identifier | ExFiles\Box 168a\3\ img110 | |
| Date | 18th August 1938 | |
| SPECIFICATION OF 5" DYNAMO. The design of the machine shall be such, as to comply with the following - (1) Type of machine. Shunt wound, with field winding connected to positive brush. Negative brush earthed. Nominal voltage 12 volts. Direction of rotation. Anticlockwise on commutator. Outside diameter shall not exceed 5". Weight shall not exceed 25 lbs. Finish. Nickel deposited. PERFORMANCE. (2) The dynamo shall be capable of being run continuously for at least six hours at the lowest speed at which it will supply at least 20.0 amperes, at 13.5 terminal volts, under the following conditions :- (a) The machine must be clamped by metal clamps to an iron bed - plate. (b) It must be completely assembled, with commutator end cover in position. The temperature of the carcase of the machine, shall be measured by a thermometer, inserted in a small metal oil bath, clamped in good metallic contact with the carcase. At the end of the run, with an ambient temperature of not less than 18°C. the rise in the carcase temperature shall not exceed 55 centigrade degrees, and the speed be not more than 1,850 r.p.m. (3) Immediately after this, the open circuit voltage at the terminals shall not be less than 13.0 volts at 940 r.p.m. (4) The dynamo shall be run at a speed of 5,500 r.p.m. and output of 18 amperes, 13 volts, when the sparking at the brushes shall be reasonable, i.e. small sparks that are | ||