Two experimental modifications to improve standard ignition coils.
| Identifier | ExFiles\Box 164\5\ img262 | |
| Date | 7th December 1936 | |
| Rm {William Robotham - Chief Engineer} /Wst.10/AP.7.12.36. IMPROVEMENTS TO R.R. STANDARD IGNITION COILS. We have recently carried out two Experimental modifications on our ignition coils which have proved to be of considerable value. The first modification tried was connecting the ends of the secondary windings in a similar manner to the scheme adopted on our aero coils and as shewn on drg. D.75672. This modified method of securing the end connection obviates the necessity for short-circuited turns on the end layer of the secondary winding and the attached curves shews the increase in output obtained. We recommend that Production coils be connected in this way. The second modification consisted of reducing the inductance and resistance of the secondary winding by re-winding it with 15,000 turns of 42 SWG. wire. This modification has the effect of reducing the total open-circuit voltage available but considerably improves the voltage output when the coil is loaded being the equivalent of when it is coupled to a leaky sparking plug. The curves attached shew the considerable improvement achieved. One of these coils is already on road test on a Bentley chassis and further coils are being produced for other cars. Rm {William Robotham - Chief Engineer} /Wst. | ||
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).