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 2 of a letter discussing the performance and advertisement of a valve's delivery curve.
| Identifier | ExFiles\Box 41\2\ Scan051 | |
| Date | 14th January 1927 guessed | |
| -2- Contd. It would be a mathematical result that in these circumstances the average delivery would be greater, corresponding as it would to a condenser of, to all intents and purposes, infinite capacity. When the delivery is directly on to a resistance with no capacity in parallel, as in your diagram I, we confirm that the delivery is similar to your A curve. For the purposes for which the valve is made it would appear to be quite reasonable for you to give a curve of smoothed delivery, this delivery being greater than that shewn in your leaflets. For instance, we recall one rough observation in which the delivery delivering unsmoothed direct on to a 150 volt Weston voltmeter was 8 m.a. at 70 volts, this agreeing with your A curve. When in the same circumstances a smoother with resistances, inductances and capacities, as shewn in diagram IV) was inserted between the instrument and the feed wire, this became much greater, i.e. 14 m.a. at 130 volts, in spite of smoother resistance. As previously implied we consider your advertised curve unnecessarily penalizes the valve in the eyes of your prospective customers and that it would be quite reasonable for you to advertise the curve of output smoothed by some specified smoothing device, as for instance, that detailed in diagram II, such a curve giving more accurately what is actually available from the valve for the purposes for which the valve is made. The undersigned willkeep in mind the offer of meeting your own technical representative sometime in London, with whom he would be interested to discuss this and other matters. Yours faithfully, FOR ROLLS-ROYCE LIMITED. | ||