Ignition system TSZ-H (Audi 80 B3)

The transistor system (TSZ) is a contactless ignition system. Instead of a breaker contact, the ignition distributor is equipped with a maintenance-free Hall sensor (TSZ-H). An ignition capacitor is not required. The contactless Hall sensor consists of a sensor, a magnet, and rotor screen plates mounted on the distributor shaft.

The Hall sensor controls the operation of the TSZ relay and thus determines the moment of switching on and off the current flow through the ignition coil. In this way, the Hall sensor determines the ignition moments.

When the rotor rotates together with the camshaft, the plates "1" run without touching through the air gap "4" of the magnetic system "2". As the plate moves in the gap of the magnetic system, it induces a magnetic field on the built-in semiconductor sensor "3" (Hall-IC). Because of this, the Hall voltage "UG" drops almost to zero, and the primary current of the ignition coil begins to flow through the TSZ block. When the plate leaves the gap, the primary current is interrupted and ignition occurs.



The number of plates on the rotor always corresponds to the number of engine cylinders. The width of the plate "b" corresponds to the rotation angle at which the output key passes current. This rotation angle does not change during the entire operation of the Hall sensor and does not require adjustment.

To protect the key cascade and ignition coil from overheating, the voltage supply to the ignition coil is switched off when the ignition is on and the engine is not running.

For safety purposes, the ignition coil has a 5.5mm hole with a plug.

It serves to ensure that in the event of a short circuit in the ignition system, the ignition coil sealant has an outlet, preventing an explosion.