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).
Page discussing the operation of a controlled dynamo and potential faults in the battery charging circuit.
| Identifier | WestWitteringFiles\O\2April1926-June1926\ Scan202 | |
| Date | 2nd June 1926 | |
| EFCL/T12.6.26. -2- Contd. The main field winding is arranged to suit this lower working voltage and would of itself be capable at that voltage of causing to pass through the armature the greater flux for the larger E.M.F., were it not for the flux impeding effect of the controlling action of the armature. The condition of working is therefore an inefficient one and is entirely different from that of a plain shunt wound machine working normally (and efficiently), on the top portion of its volt-ampere characteristic curve for some given speed, where an increase of ampere load is accompanied by a fall of voltage. The controlled dynamo is only in this (shunt machine) condition over a limited range of the lower speeds, between cutting-in and the commencement of regulation. First and foremost then, remembering that, for normal speeds at which regulation is in action, rise of terminal voltage and ampere output occur conjointly, the complete dynamo-battery charging circuit must be electrically very sound, poor connections introducing abnormal resistances such, for example, as (a) A faulty main brush carrying the whole charging current (as in a simple third brush regulated dynamo). (b) Bad switch or fuse contacts. (c) Faulty battery terminal or cell to cell connections, etc. etc. must be definitely avoided. Contd. | ||