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).
Observed functional issue with an automatic electro-magnetic switch for reducing the dynamo charge rate.
| Identifier | WestWitteringFiles\Q\December1926-January1927\ 104 | |
| Date | 22th January 1927 | |
| To R.{Sir Henry Royce} from EFC. c. EJ. E.{Mr Elliott - Chief Engineer} PN.{Mr Northey} c. Wor.{Arthur Wormald - General Works Manager} Ds. EP.{G. Eric Platford - Chief Quality Engineer} c. Ry. Cy. ORIGINAL EFC4/T22.1.27. AUTOMATIC ELECTRO-MAGNETIC SWITCH FOR REDUCING RATE OF DYNAMO CHARGE. Y4008 Further to our EFC1/T4.12.26 and EFC2/T21.12.26 we have now had these units running on two experimental chassis, one 40/50 and one 20 HP. for some time, and observations have been made of the behaviour of these units. No suggestion of failure has yet been observed. There has, however, been observed a small point of slightly incorrect functioning which is now being corrected by a simple alteration to one electrical connection. The point referred to is that as a result of the fact that, as shewn on the diagram under cover of our EFC1/T4.12.26, the negative end of the auto-switch shunt coil is connected to the A terminal of the distribution board, the phenomenon sometimes occurs that in running up the machine to excitation the auto-switch operates, due to the very temporary high voltage of the dynamo, before the cutout operates, and causes reduced rate of charge on first starting up. This does not always occur, but is liable to do so as a result of the voltage required to operate the auto-switch through its shunt coil not being greater to a sufficient extent than the operating voltage to which the cutout is set. Before the cutout has had time to operate the temporary high voltage of the dynamo is effective on the auto-switch which goes over and remains over, whereas we wish it (in these first stages of charge) to remain on contact and give full charge. Contd. | ||