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).
Metal rectifiers suitable for charging chassis batteries from an alternating current supply.
| Identifier | ExFiles\Box 32\5\ Scan026 | |
| Date | 16th December 1929 | |
| X1589 To R.{Sir Henry Royce} from EFC. c. Sg.{Arthur F. Sidgreaves - MD} c. PN.{Mr Northey} c. Hs.{Lord Ernest Hives - Chair} EFC2/ADL6.12.29. X.1589. RECTIFIER SUITABLE FOR CHARGING CHASSIS BATTERIES FROM ALTERNATING CURRENT SUPPLY. As stated in PN{Mr Northey}7/WT5.12.29 rectifying units of the Tungar type which are also made by The Philips Co. are on the market. With regard to the metal rectifier mentioned in PN{Mr Northey}'s last paragraph, these are now available for all kinds of output. They are manufactured by The Westinghouse Brake & Saxby Signal Co.Ltd. at their works in London and Chippenham. The rectifying action takes place between a copper plate and its specially oxidised copper oxide surface, contact being made with the copper oxide surface by means of a leaden plate. So far as these rectifiers have been in use, and provided certain limiting forward current densities and certain limiting backward potential differences are not exceeded, the rectifying action appears to be absolutely permanent. The units can be made up in any number in series for high voltage rectification and in extent of rectifying area in parallel, for low voltage heavy current rectification. For the latter purpose, this type of rectifier is eminently suitable, but for the former they are expensive compared with valve rectifiers which can readily stand relatively high back voltages in single units. Metal rectifiers are mainly arranged on the Wheatstone Bridge principle with four terminals, two A.C. and two D.C. for double wave rectification, incorporating which, units of various suitable sizes are made up, complete with the necessary transformer and other gear, into sets of various volt and ampere capacities. If desired, units can be obtained independently of the remainder of the apparatus. I have in front of me, an up-to-date list D.P.11, of metal rectifiers issued by The Westinghouse Brake and Saxby Signal Co.Ltd. dated May of this year in which quite a number of rectifier sets are listed, one in particular which would be of suitable capacity for charging batteries from 200 or 230 volt A.C. mains, would be their RP.10.G. unit with an output of anything between 1 and 8 amperes to a 12 volt battery, but smaller units of the same output | ||