Gas Engine Ignition; Prepared in the Extension Division of the University of Wisconsin (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1916 Excerpt: ...gear removed. Figure 96 shows the same magneto partly in section. The current from the insulated end of the armature winding is carried through a wire in the hollow stub shaft at the left to a collector plate on the end of the shaft, from which it is taken by two brushes which rub on this plate. The two brushes serve the obvious purpose of insuring a good contact even though dust or dirt lodge under one of the brushes. The connection to the other end of the armature winding is made by a brush rubbing on the bronze end plate of the armature and thence through the metal of the armature to the grounded end of the winding. Since the magneto is fastened to the engine frame, there is thus established a complete grounded return for the current, from the igniter through the metal of the engine and magneto to the grounded end of the armature winding. 61. Battery Connections.--On large engines, it is sometimes inconvenient or impossible to turn the engine fast enough by hand to secure a satisfactory sparking current from the magneto. In such cases a battery and coil can be installed for use in starting. The method of connection is shown in Fig. 97. The insulated electrode of the igniter is connected to the central pole of a double-throw switch. One pole, M, of the switch is connected to the insulated terminal of the magneto; the other pole, B, is connected to the coil. The other end of the coil and battery system is grounded to any convenient point on the engine, thus establishing connection with the grounded movable electrode of the igniter. Particular care should be taken that the connections to the switch are made so that it is impossible for any battery current to flow through the wire W and into the armature of the magneto. If battery current were allowed to flo...