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).
Investigations and improvements for the Goshawk dynamo, focusing on brushes and vibrator regulators.
| Identifier | WestWitteringFiles\J\April1923\ Scan0 | |
| Date | 1st April 1923 | |
| R.R. 235A (100 T) (S.H. 159, 11-8-20) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2800 ORIGINAL TO EFC. FROM R.{Sir Henry Royce} R1/M6. 4. 23. c. to CJ. BJ. WOR.{Arthur Wormald - General Works Manager} c. to PN.{Mr Northey} E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} c. to BY.{R.W. Bailey - Chief Engineer} HS.{Lord Ernest Hives - Chair} EP.{G. Eric Platford - Chief Quality Engineer} RE. GOSHAWK DYNAMO. I am in receipt of yours of 26/3/23. and very pleased to hear of the investigations you are making to get the RR. to have the minimum sparking at the brushes. Keep your eye very carefully on the practice of the best makes. Test all kinds of brushes available. My recommendation of LeCarbon should be used until you prove some better. The conditions under which you are working are different to those of Royce Ltd. electromotors. Test if the RR. dynamo with vibrator regulator sparks less, and brushes less trouble than with third brush regulation, also see difference in output with same temperature. There are evidently two ways of arranging vibrator regulator, that adopted by Bijur, and that used on the Scintilla. Both these are used on Bosch. Find out the patent condition of these. Using both should give the result which is most reliable at the contacts. If there are no patents in the way we ought to use both, i.e. first pair of contacts break contact and introduce a non-inductive resistance in series with shunt but this resistance is only great enough for say 100% increase in speed, possibly up to 200% increase, say from 600 to 1800; then the second pair of contacts make and short circuit upon itself the shunt exciting coil. There must of necessity be a step-up in the voltage of say 10% between the two contacts, and also there may be some advantage in using a condenser across the first pair of contacts (like we think Westinghouse.) All this we want you to find out ready for us to arrange our own vibrator regulator. Which I think we must conclude is desirable if thoroughly reliable. I also think it should be understandable by an intelligent electrician, i.e. it should be an obvious apparatus like the ignition, and not stowed away as a sealed mystery as Bosch has made it. R.{Sir Henry Royce} | ||