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).
Instructions detailing the electrical and acoustic properties of a horn.
| Identifier | ExFiles\Box 49\5\ Scan128 | |
| Date | 8th December 1924 | |
| ROLLS-ROYCE LTD. INSTRUCTIONS. RR 238 (150 BKS.) (DB {Donald Bastow - Suspensions} 461-8-12-24) MP 306975 To________________ 19____ Order No._________________ Customer's No. __2__ resistance across it there being a pair of wires connected to it which suggest this, though it is not visible. There is no circuit through when the contacts are open. The horn will operate on 8.0 volts taking an average current of 2.25 amperes. On 16.0 volts the current rises to 4.5 amps and the pitch frequency rises from about 240 per sec to 270 per sec in the same range. At a normal voltage the note produced is extremely loud and it is clear of unwanted buzzing &c. A laminated steel strip mounting for the horn is provided. Signed F.A. This Sheet must be filed on completion of the work. | ||