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).
Report comparing operating voltages of dynamo cut-outs and discussing measures to improve their uniformity.
| Identifier | WestWitteringFiles\D\May1920\ Scan33 | |
| Date | 14th May 1920 | |
| R.R. 235A (100 T) (S. G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 643, 19-2-20) G 2618 Contd. -6- EFCI/T14.5.20. Comparison of the operating voltages in the above six tables will show that these agree quite well with those given in tables B and C for the cold condition, except in the case of cut-out No.91, which was particularly indefinite as already explained, but that in the hot condition, there are considerable differences between the operating voltages (i.e. for 1. condition). It will be noticed that generally speaking there is a bigger range between cold and hot of combined cutting in speed of dynamo and cut-out than of balancing speed of dynamo alone, which further proves the desirability of lowering the range of operation from cold to hot on the cut-out by the use of a non-temperature coefficient resistance in series with this. This matter of the want of uniformity of the cut-outs has, we believe, been taken up with Messrs.Lucas by Mr. Bailey. They have been supplied with copies of our specification of what the dynamo and cut-out should do and with copies of tables A and B, which we have passed to Mr. Bailey for the purpose. We hope by this means to secure a better uniformity in the cut-outs in the switchboxes which are being delivered to us at the present time. KWs | ||