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).
The performance specifications and testing of Lucas dynamo cut-outs.
| Identifier | ExFiles\Box 36\4\ scan 033 | |
| Date | 14th May 1920 | |
| S. R.{Sir Henry Royce} 238a (100 T) S. G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 643. 19-2-20 G 2618 EFC1/T14.5.20. -2- Contd. circuit voltage and therefore late in operating the cut-out. This we are suggesting returning to Messrs. Lucas for investigation. Generally speaking, the Lucas dynamos are fairly uniform in performance, at any rate in the cutting in points, if perhaps they vary a little in out-put. With regard to the cut-outs, our specification states that they shall be operated when cold at a voltage on the shunt coil lying between 12.0 and 13.0 and a current not exceeding .30 ampere, and further that the reverse current to de-operate shall not exceed 3.0 amperes. The specification is only made out for the cut-outs in a cold condition. The results of taking the six cut-outs through our specification are exhibited on table B attached. This table shows considerable variation from cut-out to cut-out, in (a) Volts on shunt coil to operate. (b) Resistance of cut-out shunt coil. (c) Series reverse amperes to de-operate. It should be stated that these figures were taken making use of a dynamo as a source of current, connected up in the ordinary way to the cut-out. Further, they are the averages of two sets of readings taken at different times on the cut-outs, which two sets were in moderate agreement with one another. Contd. | ||