CHAPTER XIX
ATWATER KENT IGNITION SYSTEMS
Construction, Operation and Care
Atwater Kent ignition systems have been adopted of late by many prominent automobile manufacturers as a means of distributing or conveying electrical spark to the cylinders at the proper firing time.
This type of quick break distributing system has proved very efficient and dependable, and will usually outlast the life of the motor as there are very few moving parts, which eliminates troubles caused by worn parts getting out of adjustment.
This type of ignition system operates in much the same manner as the high tension magneto, and differs only in that the parts have been taken from the compact magneto case and distributed in other locations in separate units. As this type takes its current from the lighting and starting battery, it does not contain an armature or field magnets to manufacture the electrical force.
[Fig. 66] illustrates the principles of operation of the type CC Atwater Kent closed circuit system, which consists of the unisparker containing the contact maker and distributor. The only moving parts are located in this unit. The coil consists of a soft iron core, with a primary and secondary winding sealed in an insulated tube or container. A resistance unit is located in the top and regulates the current automatically. The system is controlled by a switch located on the dash. The contact breaker shown in [Fig. 67] consists of an exceedingly light steel contact arm. One end rests on a hardened steel cam which rotates one-half as fast as the crank shaft. This cam has as many sides as the engine has cylinders. When the contact points are opened by the movement of the cam the primary circuit is broken and produces a discharge of secondary high tension current at one of the spark plug gaps.
| CONTACT MAKER | TO PLUG TO PLUG |
| DISTRIBUTOR | |
| CONDENSER | |
| TO PLUG | |
| CONTACT MAKER GROUNDED | |
| SPARK PLUG | |
| BATTERY GROUND | |
| PRIMARY | |
| BATTERY | GROUND |
| SWITCH | |
| SECONDARY | |
| GROUND | |
| REGULATING RESISTANCE |
Fig. 66. Atwater Kent Circuit Diagram—Type CC
[Fig. 68] shows the simple Atwater Kent contactless distributor. The high tension distributor of the Atwater-Kent system forms the top of the contact maker. Each spark plug wire terminates in an electrode, which passes through the distributor cap. A rotating distributor block takes the high tension current from the central terminal and distributes it to the spark plugs in proper firing order. The distributor block or arm does not make direct contact with the distributor posts. The current jumps the small gap between the distributor block and the terminal electrodes and does away with frictional wear resulting from actual contact.
