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).
Diagram of connections for a transformer switchboard.
| Identifier | ExFiles\Box 32\4\ Scan061 | |
| Date | 27th February 1926 guessed | |
| TRANSFORMER SWITCHBOARD. DIAGRAM OF CONNECTIONS. V 1521 205V AC LAMPS. FUSE. + - LT TRANSFORMER. TEST. H.T. TRANSFORMER. REGULATING RESISTANCE 46B | ||