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).
Continued description of a dynamo's operation, detailing its two-pole winding, armature resistance, and the Rotax Leitner regulation principle.
| Identifier | WestWitteringFiles\C\May1919\ Scan45 | |
| Date | 7th May 1919 | |
| Contd. -2- a two pole winding; it has 30 slots and there are 30 commutator segments. The resistance of the armature is .44 ohm measured cold. The connections of the various windings to the various brushes, and the directions of flow of currents and of rotation are indicated on diagram F.{Mr Friese} The scheme of regulation is on the Rotax Leitner principle, in which a series winding wound round the main poles is connected between a third brush and one of the main brushes. In this instance the winding is connected between the control brush and the negative brush as indicated by the main diagram on sheet F in conjunction with the small diagram (c). (on same Sheet F) Referring to the main diagram on sheet F ( and supposing that the main terminals F,C, and -, are connected together as in diagram (c) ) the action of the dynamo is as follows:- On first starting up, the control brush is opposite to the negative brush and current flows through the control winding in the direction opposite to that indicated by the arrows, i.e. in such a direction as to assist in the building up of the main field. The control current and field current rise together progressively as the speed increases until such a point that the voltage of the dynamo is sufficient to cause the cut-in to operate. After this point, and with further increase of speed owing to the increase of main current, the main flux passing across the armature is gradually pulled round further and further in the direction of rotation, so that the voltage between the control and negative brushes gradually decreases, and with it the control current, at first. The control current soon Contd. | ||