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).
Letter from Societe Des Etablissements L Bleriot discussing the specifications and adjustment of automatic electrical switches.
| Identifier | ExFiles\Box 48\3\ Scan236 | |
| Date | 19th April 1921 guessed | |
| -3- Contd. its "cutout" point is 12 v. {VIENNA} We understand by "warm" after a full run during 2 hours under 14v.5 with a current of 10 amps. The automatic switch being placed in free air and the ambient temperature being 19°C, then the automatic switch temperature reaches 36°C. The reverse current never exceeds 0.8 to 1 amp. and the current to operate the automatic switch being in either case lower than 0.2 amp. as you require it. Generally we are obliged to have such a difference between the "cut-in" and "cut-out" tension because our automatic switch is fitted on different installations having dynamos which have a different coefficient of "armature reaction" and we must have only one type of cutout to fit any kind of installation, but in a special case like yours, for example, we may have a special setting more accurate, as our compensated automatic switch can be adjusted in the most accurate manner, and then for the "limits we should have to do some tests, for which we remain at your entire disposal. Our firm in London in accordance with your request have adjusted a few automatic switches according to your specifications, but we think it would be advisable for you to take our setting up points for the reasons given herein on account of the great experience we have had in this matter. Awaiting the favour of your reply, We are, dear Sirs, Yours faithfully, SOCIETE DES ETABLISSEMENTS L BLERIOT. (Signed) P. Marchal. | ||