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 a supplier requesting clarification on test procedures for an ignition coil spark-gap.
| Identifier | ExFiles\Box 167\3\ img106 | |
| Date | 4th May 1938 | |
| SPECIALISTS IN THE TRANSMISSION, TRANSFORMATION AND CONTROL OF ELECTRICITY. TELEPHONES: GREENWICH 3244 (10 LINES) GREENWICH 0047 (BUYER ONLY) TELEGRAMS: 'JUNO, CHARLTON-KENT'. ESTABLISHED 1875. CABLES: 'JUNO, LONDON'. CODES: NEW STANDARD. JOHNSON & PHILLIPS, LIMITED ELECTRICAL ENGINEERS AND CABLE MAKERS. CHARLTON LONDON, S.E.7. LONDON OFFICES: COLUMBIA HOUSE, ALDWYCH, W.C.2. TELEPHONES: HOLBORN 7676 (8 LINES) TELEGRAMS: 'JUNO, LONDON'. BRANCHES IN: BIRMINGHAM, BRADFORD, BRISTOL, CARDIFF, GLASGOW, IPSWICH, MANCHESTER, NEWCASTLE-ON-TYNE, PORTSMOUTH, SYDNEY, MELBOURNE, WELLINGTON, JOHANNESBURG, NAIROBI, CAIRO, CALCUTTA, BOMBAY, SHANGHAI, SINGAPORE, ACCRA, RANGOON, COLOMBO, MALTA. YOUR REF. OUR REF. CE. A.G. 4th May, 1938. Messrs. Rolls-Royce Ltd., DERBY. Dear Sirs, With reference to your Specification No. E.L. 9/1 and to the Ignition Coil which we purchased from you in November under reference RM{William Robotham - Chief Engineer}/RC{R. Childs} 2/JH, we are having difficulty in interpreting the conditions of the test referred to in Clause 6. of your Specification in respect of the spark-gap. We should like to know whether the spark-gap is continuously in circuit during test, that is, to simulate working conditions, if so, is the gap calibrated to spark over at some voltage less than 10,000 volts? We should like to have details of the method of calibration and also the spark gap distance found to be most suitable for test purposes. Your early reply will be very much appreciated. Yours faithfully, Johnson & Phillips, Limited. (Cable Engineer) Handwritten text: Top of page: 6110 Left of body text: 4.2 m/m Bottom left: LEL | ||