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).
Two designs for a modified single spark coil to produce a single spark instead of a series.
| Identifier | ExFiles\Box 34\1\ Scan005 | |
| Date | 28th May 1914 | |
| X 2512 S. & M.{Mr Moon / Mr Moore} T. (S. G.{Mr Griffiths - Chief Accountant / Mr Gnapp}) 645. 19-2-20. G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2618 To Mr. Ellis. from R.{Sir Henry Royce} c. J.{Mr Johnson W.M.} c. Wor.{Arthur Wormald - General Works Manager} c. NB. c. E.{Mr Elliott - Chief Engineer} R9/P28.5.14. X.1317 - SINGLE SPARK COIL. X.562. X.2512. X.1520. We send you two designs of a coil modified, so as to give a single spark instead of a series of sparks. We send you two ways for you to construct it, so that you can test and see which is the better way. The objects of this arrangement are :- 1. To lessen the risk of leakage of the second spark. 2. To reduce the necessity of separating the wires. 3. To enable the small sized distributor to be used. 4. To reduce the noise and the current consumed. You will notice in the arrangement that we can at will by burning the switch render this part inoperative during starting operations should we wish it. With this arrangement the condenser can be in the usual position across the platinum contact of the trembler, and across the low tension contact maker; or it may be possible to fit it between the beginning and the finishing end of the primary winding. There should also be another condenser of unknown size belonging to this extra coil. The scheme of single spark coil is a very old one, and I should be glad if the patents were looked up. I have in mind one or a similar device, made by Bradley, round about 1904 which I believe he patented. LeC.160 & 161 sent by Mr. Elliott. R.{Sir Henry Royce} | ||