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).
Issue of connecting cigar lighters to the 20 amp ammeter circuit on 'Phantom' cars, proposing a separate fused circuit.
| Identifier | ExFiles\Box 65\2\ scan0237 | |
| Date | 25th March 1929 | |
| S/W. from PN.{Mr Northey} Copy to EFC. X7741a PN.{Mr Northey}3/WT25.3.29. Probably the following point has been considered previously but so far no decision has come to our knowledge. The ammeter provided by us on "Phantom" cars is capable of reading up to 20 amps. only. It has been the practice to connect up such instruments as cigar lighters in such a way that the current taken by them also passes through the ammeter - at a time for instance at night when the sum of the currents flowing through the ammeter is considerably greater than the scale of the instrument can indicate. This of course is undesirable and it would appear best so to arrange any additional current such as a cigar lighter taking upwards of 15 or more amps. independently of the ammeter. I shall be glad to have your remarks on this matter, and sketch showing the point at which you would propose to take off the cigar lighter circuit, also showing the provision of the necessary additional fuse. PN.{Mr Northey} | ||