The ignition system works as follows. The low voltage from the battery is fed to the ignition coil, where it is converted into a high voltage, the magnitude of which is sufficient for a spark to jump between the electrodes of the spark plugs at high pressure developed in the cylinders. The ignition system is divided into 2 circuits: high and low voltage.
Low voltage circuit (sometimes also called primary) consists of a battery, a wire leading to the ignition switch, a wire leading from the ignition switch to the primary winding of the coil, and a wire leading from the primary winding of the coil to the breaker contacts and the capacitor in the distributor.
High voltage circuit (secondary circuit) consists of the secondary winding of the coil, the ignition wire leading from the center electrode of the coil to the center electrode of the distributor cap, the runner, the ignition wires leading to the spark plugs, and the spark plugs themselves.
The ignition system works as follows. Low voltage is converted into high voltage in the ignition coil by opening and closing the breaker contacts in the low voltage circuit. High voltage is applied through "ember" covers of the distributor to the slider rotating on the roller of the distributor. Whenever the runner is aligned with one of the four electrodes located in the distributor cap and connected to the ignition wires, the opening of the breaker contacts causes a high voltage to build up, leading to a spark between the runner and the corresponding electrode. Voltage is transmitted through the ignition wire to a candle, between the electrodes of which a spark jumps, leading to ignition of the mixture.
In order for the ignition of the mixture to take place at the right time in relation to the speed and load of the engine, the ignition timing is automatically adjusted.
The ignition timing is controlled by mechanical and vacuum regulators. Mechanical (centrifugal) the regulator consists of two weights, which, due to centrifugal force, diverge with an increase in the speed of rotation of the distributor roller and turn the cam relative to the distributor roller, thereby accelerating the spark. The weights are held by two springs, and the correct mechanical adjustment of the ignition timing depends on the tension of the springs.
The vacuum regulator consists of a membrane, one side of which is connected by a thin tube to the carburetor, and the other side to the contact breaker plate. The vacuum in the intake manifold and carburetor, which varies with engine speed and throttle opening, causes the diaphragm to move, which accordingly moves the contact breaker plate, speeding up or slowing down the spark.