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).
Proposing to use a cheaper moving iron type ammeter instead of the current moving coil type for cost reduction.
| Identifier | ExFiles\Box 168\5\ img212 | |
| Date | 30th May 1931 | |
| X6132 Extract from memo in X.6084 ref. Hs{Lord Ernest Hives - Chair}/H.M/AD30.5.31. Ammeter. If we wish to reduct costs we suggest that we might use an ammeter of the more usual moving iron type instead of the present moving coil type. We do not consider that an extremely accurate instrument is necessary for the following reasons : (1) It is impossible to read on the present instrument with any degree of precision, fractions of an ampere. (2) When the car is in motion, the oscillatory motion still more prevents any precision in reading the instrument. From a customer's point of view the ammeter is only used to indicate roughly whether it is charging or discharging. (3) We know of no other car which use this type of ammeter. Ferrenties will supply moving iron type instruments of good qualities at 15/- less than we are paying at present. Hs{Lord Ernest Hives - Chair}/Hst. | ||