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).
Differences in distributor sparking based on the direction of current flow.
| Identifier | WestWitteringFiles\K\September1923\ Scan43 | |
| Date | 14th September 1923 guessed | |
| -3- Contd. There are chiefly three differences between the sparking in the distributor with the current flowing the right way and the wrong way. (1) With the current flowing the wrong way there appears to be a tendency for the sparks to start crossing in the distributor, in preference to the spark gap, earlier, i.e. with a smaller length of spark gap than is the case with the current flowing the right way. For larger gaps, however, there is a greater tendency for sparking to occur in the distributor with the right direction of coil primary current than with the wrong. (2) With the current flowing in the right direction the sparks wander. That is, some pass straight from spark point to spigot, some strike first the inside surface of the distributor moulding and travel over that surface to the spigot, while others pass straight from rotor blade to spigot in between spark points or from rotor blade to the inside surface of the distributor moulding at the bulge in the moulding formed by the securing strap pockets. On the other hand, with the current in the wrong direction, the sparks pass nearly consistently from the sparking points to the surface of the moulding just above the spigot, travelling over that surface to the metal. (3) With current in the wrong direction, some sparking occurs from both the point and the tail of the rotor blade, to the condenser rivets. This does not occur with current flowing the right way. The shortest distance between the rotor blade and condenser rivet heads is about 9.5 mm, and that between spark points and the inner edge of the spigot about 9.0 mm. CAP. | ||