The Complete Automobile Instructor3

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. 1907 edition. Excerpt: ...too long in contact at low speeds. If the timer works (For questions to answers on this page, see p. 18.) satisfactorily when new, it can be kept in that condition only by care and attention from the operator. LOW-TENSION IGNITION 1. The low-tension system of ignition is socalled because an electrical current of low voltage is used to produce a spark within the cylinder. 2. The current may be derived from either dry cells, storage-batteries, or a magneto, although the magneto is the usual source of current. 3. Either alternating or direct current may be used, and the voltage depends upon the speed of the armature of the magneto, ranging from 4 to 20 volts. 4. When either storage or dry batteries are used, a spark-coil is necessary, but when a magneto is used the armature-winding serves the same purpose. 5. A stationary electrode is insulated and inserted within the cylinder. Another electrode having an arm within the cylinder placed conveniently near is capable of being moved from the outside of the cylinder into contact within the cylinder with the stationary insulated elec trode and then rapidly separated. (For questions to answers on this page, see p. 18.) 6. The movable electrode is not insulated from the motor, and when it makes contact with the insulated electrode the electrical circuit is completed through the motor back to the source of current. 7. The spark which is created by the rapid separation of the points in contact is the result of the self-induced current of the spark-coil or armature-winding prolonging the flow of electricity which follows the moving electrode. 8. Platinum or iridium points are used for contacts, because these metals resist the oxidizing effect of electricity and heat better than other metals. 9. The duration of...