Coil Head Contact Breaker.
Fig. 28 shows the details of a contact breaker to be attached to the coil head direct. It is often used on very small coils, which, together with a miniature dry cell, is slipped into a pocket case. An important detail in small coils is to use a contact breaker of sufficient size. Most of them are not large enough to stand ordinary usage, the adjusting screw is not of sufficient diameter and the thread soon strips. There is no reason why the adjusting screw, its platinum tip, and the pillar or lug which holds it should not be solidly built, it would certainly require less adjustment. Either single or double check-nuts can be fitted to the adjustment screws of nearly all the forms of contact breakers described.
Fig. 28.