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).
The Terry Ignition System, a battery and condenser system producing efficient sparking with low current consumption.
| Identifier | ExFiles\Box 37\1\ scan 071 | |
| Date | 14th January 1920 guessed | |
| X3199. The Terry Ignition System. Battery and Condenser System Producing Efficient Sparking with Low Current Consumption. ANY interesting inventions are often to be seen at the works of Messrs. Leopold Ward, Experimental Engineers, Harmood Place, Chalk Farm, London, N.W.1. We were recently invited by Mr. Ward to inspect a new battery ignition system, the Terry, made for an inventor. At first sight the peculiarity of the system reveals itself in the number of flash lamp batteries coupled together which form the source of electricity. There are no fewer than eighteen of these, each giving 4½ volts. The most interesting feature of the system is the extremely low current consumption—one-fortieth of a milli-ampère. The current does not flow across the points of the plug when the contact-breaker points separate, but passes when they make contact, and, when this occurs, use is made of the condenser, the discharge of which provides the necessary volume of current. In the experimental set demonstrated to us, the principal parts of the distributer and contact-breaker were made out of parts of a high-tension magneto. It is easy to recognise the magneto, distributer, and contact-breaker, of which the latter has been altered to suit this system, contact in the two circuits being made by the original platinium points and an additional wiper. The diagram will give the reader a good idea of how the scheme is carried out. It will be noticed that there is a contact breaker between the battery and the condenser, and a further contact breaker between the condenser and primary winding of the coil. A small water resistance of about 2,000 ohms is placed in the circuit between the coil contact-breaker and the primary coil as a safeguard in case of a short. When the battery contact-breaker makes contact, the condenser is charged; the battery circuit is then broken and connection is next made between the condenser and the coil, the condenser discharge passing through the primary of the coil and inducing the secondary current at the plug. The apparatus is provided with two sparking plugs working under a pressure of 80 lb. to the square inch. When the device was set in motion, at an extremely slow speed, it was noticed that as the pressure rose on the chamber being filled with compressed air (from atmospheric pressure to the maximum), the spark at the plugs increased in intensity instead of decreasing, probably due to the oscillatory nature of the discharge through the current of the primary. The whole arrangement is most interesting, and we do not see why it should not work well in actual practice. The Royal Automobile Club has long been striving to re-establish the hotel service of the country on a basis satisfactory to motorists and other hotel users. Usually the representations made by the Club to hotel proprietors are cordially received, but in some cases resentment is shown to the suggestions put forward for the mutual benefit of hotel keepers and their clients. The Club makes the utmost effort to secure proper facilities for motorists wherever these are lacking. EIO [Wiring Diagram Labels] Battery Battery Contact Breaker Condenser Coil Contact Breaker Resistance 2,000 Ohms Primary Coil Secondary Coil Plug Earth [Wiring Diagram Caption] The wiring diagram of the Terry ignition system. [Apparatus Image Labels] PRESSURE GAUGE AIR PUMP CONNECTION BATTERY OF 18 FLASH LAMP CELLS COMPRESSED AIR CHAMBER FOR TESTING PLUGS UNDER COMPRESSION CONDENSER COIL WATER RESISTANCE H.T. DISTRIBUTOR ELECTRIC MOTOR FOR WORKING CONTACT BREAKERS AND H.T. DISTRIBUTION DOUBLE ACTING CONTACT BREAKER [Apparatus Image Caption] The Terry ignition system under test; the electric motor and compressed air chamber form part of the testing apparatus, and should not be confused with the ignition system. | ||