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).
Test procedures for checking various gaps and performing electrical tests on a switch.
| Identifier | ExFiles\Box 168a\2\ img154 | |
| Date | 17th April 1935 guessed | |
| -2- (7) The various gaps should be checked over and confirmed to agree with the gaps and limits given on the sheet herewith. The table of gaps is made up on the assumption that the following gaps are first fixed. (a) Air gap at core centre- switch full on .010 - 2 (b) Core to armature stop when first coppers are just in contact. .045 (c) Copper gap when carbons are just in contact. .040 (d) Carbon gap, switch in fully off position. .025 +5 II. ELECTRICAL TEST. (1) The coil of the main switch shall be connected to the terminals of a six volt battery, through an ammeter, and the current taken by the coils (with non-inductive resistance in parallel) at 6 volts at atmospheric temperature shall be noted. This shall lie within the limits 3.3 and 3.5 amperes. If it does not fall within these limits, there may possibly be an open circuit through the resistance coil and in that case a test should be made for continuity through the resistance coil alone. (2) With the switch unit standing flat on its base a gradually increasing current shall be passed through the coil of the main switch (with its non-inductive resistance in parallel) and the current noted at which the switch pulls right down. This current shall not exceed 2.25 amperes and | ||