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).
Technical comparison of vibrator control systems, including carbon plate regulators and metallic 'dithering' contacts.
| Identifier | ExFiles\Box 165\6\ img252 | |
| Date | 27th December 1929 | |
| EFC3/AD27.12.29 contd. -4- scheme also is subject to what appears to us the one objection to such schemes, namely the lightness of the pressure on the contact points during normal working. With regard to Mr.Northey's memo PN{Mr Northey}3/WT23.12.29 the system referred to was of the type which may be considered to be half way between the type of vibrator control with metallic points giving a nearly definite change of resistance included in the field winding, and the type of carbon plate regulator where the resistance included in the field winding is variable progressively within certain limits. In the case now considered there was a single pair of large carbon points and the action between these took place considerably by variation of the contact resistance between these carbons, which were gradually burnt away from point to point across their area. We made tests at the time Mr.Northey sent this machine to us, complete records of which we have, and our conclusion was that that particular arrangement was at least as good in operation as any metallic "dithering" contact point arrangement such as Bijur and Westinghouse of which we also have had experience. We have never been satisfied with the consistency of setting of what we call, for want of a better term "dithering" vibrating contacts. The most consistent one in our experience has been the R.Bosch (on Post War) and that did seem to work very well so far as tested on the bench only. The R.Bosch system however, | ||