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).
Comparison of a Scintilla electrical unit's performance against an R. Bosch system, noting issues with operating voltages and complexity.
| Identifier | WestWitteringFiles\K\June1923\ Scan55 | |
| Date | 12th June 1933 | |
| To R.{Sir Henry Royce} Contd. -10- EFC1/T12.6.33. so that this would be the value of the regulated current before operation of the auxiliary relay, when the battery is alone in the circuit. One of the objections to this Scintilla unit appears to be the very close magnetic circuits which are utilised, resulting in a big difference between operating and de-operating voltages, for the auxiliary relay and cutout. In the case of the cutout we found this to require 12.6 volts to operate cold, and 17.5 volts hot, and reduction to as little as 7.0 volts cold and 10.0 volts hot to cause deoperation to occur. Further, we found that the reverse amperes cold to deoperate with 12.3 volts across the field coil were as many as 4.5. We do not like the whole arrangement. It seems unnecessarily complicated for the comparatively simple work which it has to perform. The R.{Sir Henry Royce} Bosch arrangement is very much simpler in principle and appears to do the work of regulation a good deal better and within narrower limits. The R.{Sir Henry Royce} Bosch is the only system of this kind which we have tested which has appeared to be right from the start to the finish, working exactly in the way that would be expected from principles, giving no trouble from abnormal effects and appearing to meet the demand for current in a reasonable way, whatever the nature of that demand. The same cannot be said of the Bijur, Westinghouse and others which we have tested. Contd | ||