Constant current control system for a shunt wound machine, with notes on a sample dynamo and instrument fixing methods.
| Identifier | ExFiles\Box 3\5\ 05-page029 | |
| Date | 15th January 1919 | |
| - 2 - BY10/P15119. contd. shunt wound machine. The control system follows the constant cur- rent scheme and is obtained by short circuiting two brushes at right angles to the two main brushes through a slight resistance, the current set up in the armature by these auxiliary brushes produces a magnetic flux in armature which at first strengthens but later weakens the main flux. It certainly appears from the curves submitted to give a very rapid rise of current, more rapid actually than a simple shunt machine with a very efficient control when the maximum position of output has been reached. Messrs. Smith are sending to us in the course of a fortnight, a sample dynamo with switch, which we propose to test out exhaustively on the bench, from which experiments we will obtain a complete set of curves which will be sub- mitted to you in due course. At the moment I must say that I consider the system is very promising, and their various instruments certainly seem to be well designed, although the switch which I am sending you has not got the finish it should have, owing to being a sample instrument, hand made. I would like to draw attention to their method for fixing the three instruments, namely, Speedometer, Clock and switch in the instrument board, which allows a speedy detachment for examination, but may, in the course of time, leave the instrument a little slack, although if | ||
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).