Zündkontaktpunkte

Zündkontaktpunkte, also known as breaker points or contact breaker points, are a mechanical component found in older ignition systems of internal combustion engines. Their primary function is to interrupt the primary circuit of the ignition coil at precisely the right moment, inducing a high-voltage spark in the secondary circuit. This spark then ignites the fuel-air mixture in the engine cylinders.

The system consists of a pair of electrical contacts, typically made of a durable alloy like tungsten. These contacts are mounted on a movable arm and a stationary post. As the engine rotates, a cam attached to the distributor shaft opens and closes these points. When the points are closed, current flows through the primary winding of the ignition coil, building up a magnetic field. When the cam lobe pushes the movable arm, the points separate, breaking the primary circuit. This sudden interruption causes the magnetic field to collapse rapidly, inducing a high voltage in the secondary winding of the coil, which is then delivered to the spark plug.

The timing of the point separation is crucial for engine performance and is determined by the shape of the cam and the gap between the points when fully open. Over time, the contact points can wear down, become pitted, or become coated with carbon deposits, leading to misfires, poor fuel economy, and rough running. Regular maintenance, including cleaning and adjustment of the point gap, was essential for older ignition systems. Modern vehicles have largely replaced breaker point systems with electronic ignition systems, which offer greater reliability, precision, and require less maintenance.