Make and Break Ignition

—Electric ignition of explosion motors, effected by bringing two platinum points together and then separating them, thus forming an are or electric spark. The points are brought together by mechanical means, and separated by a spring, a low tension current being employed which is derived from either a primary or a storage battery. While it is po ible to produce a spark by simply breaking a low tension circuit, it is nece ary in order to have a spark of sufficient intensity and duration to introduce into the circuit a primary a induction coil, which consists of a long iron core wound with a considerable length of low resistance insulated copper wire; the length of the core and the number of turns of the wire determining the efficiency. When a magneto is used, a coil is not nece ary as the armature winding serves the same purpose. In make and break ignition a considerable interval of time is required for the current to rise to its full value, hence the time of separation of the platinum points should not occur sooner than the moment when the maximum current strength has been obtained. Make and break ignition is also called low tension ignition