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 notes on the construction and performance characteristics of an electric horn.
| Identifier | ExFiles\Box 59\3\ Scan052 | |
| Date | 8th December 1924 | |
| RR 238 (150 BKS.) (OB 461-8-12-24) MP 306975 ROLLS-ROYCE, LTD. INSTRUCTIONS. To____________________ .................................................19__ Order No._______________ Customer's No. 2 There is a condenser across the vibrating contacts. The cover is of cast iron and carries the operating mechanism within it. It is removable by undoing the screws which hold the trumpet and diaphragm and thus cannot be seen whilst working. External provision is made for adjusting the contacts and the diaphragm. The coil resistance alone is .70 ohm and with the inductance in series 1.17 ohm. On the loud note connection the horn operates easily on 8.0 volts taking 1.5 amperes average current rising to 2.5 amps at 16.0 volts, the loudness of the note increasing with the voltage but the pitch frequency remaining at 270 per sec. The note is clear but not so loud as Signed__________________ (Cont'd) This Sheet must be filed on completion of the work. | ||