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 analysis of regulator coil performance, current variation, and temperature compensation.
| Identifier | WestWitteringFiles\F\February1921\ Scan72 | |
| Date | 2nd February 1921 | |
| Contd. -5- EFCl/T2.2.21. from 3 amperes to 11 amperes within the regulating range (without temperature variation) with the regulator field current coil in circuit. On omitting this coil from the circuit and re-adjusting the regulator suitably, we found the amperes to vary only from 3 to 4 within the regulating range. (N.B. It would be expected to increase by an amount approaching one ampere owing to the reduction of the field current by this amount in the main compound coil). Hence it would appear that if the field current is led round the regulator core at all, the coil should be wound with a few turns in a demagnetising direction so as to level up the natural tendency of the voltage to rise in the purely volt coil operated case. This being done and a suitable amount of compounding being provided, we should have a control which is almost entirely independent of speed within the regulating range. There still remains, however, the effect of temperature of the volt coil. On this particular instrument we found that with rise of temperature, the operating voltage was appreciably higher, as would be expected, and the current delivered to a battery in a given condition at the same speed was considerably more, whether the regulator field current coil was omitted or not. To compensate for the effect of temperature, it would be necessary to rearrange the volt coil circuit with a relatively large amount of zero temperature coefficient wire so that the magnetising effect was practically identical for the same voltage whatever the temperature. Contd. | ||