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).
Car dynamo output and alternative battery charging technologies.
| Identifier | ExFiles\Box 32\5\ Scan024 | |
| Date | 5th December 1929 | |
| X1589 R.{Sir Henry Royce} from PN.{Mr Northey} Copy to EFC. Sg.{Arthur F. Sidgreaves - MD} PN{Mr Northey}7/WT5.12.29. CAR DYNAMO OUTPUT. X.8780. X.294 X.1589 Referring to your R2/M3.12.29. I am glad that you ask for 1 and 2. in this memo. The larger output generator is badly wanted even if it is at the expense of cutting in a bit later. Sg.{Arthur F. Sidgreaves - MD} has asked whether we are aware that sundry less expensive cars of today have a two-point switch for charging. It is sometimes referred to as "summer charge" and "winter charge", the former charge is at the rate of 2 to 3 amps, and the latter at 8 to 10 amps. There seems quite a lot in this idea. I think the fact that alternating current generation is nowadays altogether more common is in our favour from the point of view of simple trickle charging, because so many devices have been perfected from the wireless point of view enabling rectifying and transforming of alternating currents to be easily and cheaply done. For instance, there is the well known Tungar valve device enabling a current of from 3 to 6 amps to be available for charging against 6 to 12 volts. This device is entirely reliable. It is made by B.T.H., G.E.C. etc. Then again when smaller currents are to be used, about .5 amps, there is an excellent metallic rectifying device sold by Ferranti, in which there are no moving parts and there is no valve, and also is quite inexpensive. PN.{Mr Northey} | ||