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).
Production test procedures for an ignition coil.
| Identifier | ExFiles\Box 69\1\ scan0186 | |
| Date | 18th February 1929 | |
| 18.2.29. X. 8781 cl. PRODUCTION TEST OF IGNITION COIL. X.8710 X. 5781 cl. (22 S.W.G. PRIMARY 18,000 TURNS SECONDARY) (D.70346). (Amended to suit 1¼ value ballast resistance) (1) Continuity of primary and secondary circuits shall be tested by applying an A.C. voltage of 200 to the secondary, when a small 4 volt lamp connected across the primary should be lighted. (Care should be taken to secure a definite metallic connection to the high tension terminal of the secondary winding.) (2) Now test for short circuited turns, etc. in either secondary or primary, by inserting a Weston A.C. milliammeter in the supply circuit, when the milliamperes of current taken by the secondary winding, with the primary open circuited, should not exceed the limit 16.5 (3) The high tension terminal is now connected to the central terminal of an RR. chassis distributor, it being supposed that the distributor is already connected in sequence to six spark gaps. The primary of the coil is connected up in series with a 12 volt battery, a standard ballast resistance (35" of 32 S.W.G. nickel wire), switch, ammeter, and an RR. contact breaker with standard condenser (.275 to .325 microfarad at 18°C) across its contact points, the make ratio of these latter being set to .55. This make ratio should be periodically checked. A convenient way of doing this is to keep a small resistance made up non-inductively which, when placed | ||