Crankshaft/camshaft sensors

Hall-effect-based sensors for the crankshaft and camshaft play an important role in modern engine management systems. They work contactlessly and precisely to determine the position and rotational speed of these components. With the appropriate circuit design, these sensors also achieve a very high temperature resistance, which is understandably very important in relation to the application.

How it works:

1. Basic principle of the Hall effect: RHEINTACHO sensors for these applications are based on the Hall effect, in which a Hall voltage is generated when a current-carrying conductor is exposed to a magnetic field. This voltage is used to detect changes in the magnetic field.
2. Sensor design: Hall effect sensors consist of a Hall element and a magnet. The crankshaft or camshaft is equipped with a gear-like structure or markings that have magnetic properties or can influence a magnetic field.
3. Signal conversion: As the crankshaft or camshaft rotates, the teeth of a sensor target move past the sensitive area of the sensor and change the magnetic field. The Hall element detects these changes and converts them into electrical signals. Each signal corresponds to the passage of a tooth or a marker and represents a specific position or speed.
4. Position and speed detection: The electrical signals generated by the sensors are forwarded to the engine control unit (ECU). Here, the data is analyzed to calculate the exact position and rotational speed of the crankshaft or camshaft. This allows the ECU to precisely control the ignition timing, fuel injection and other engine processes.
5. Crankshaft and camshaft synchronization: The camshaft sensor is often used to determine the relative position to the crankshaft. This synchronization is crucial for the correct control of valve opening and closing times.
   It is achieved by the target having a deliberate irregularity at one position, for example. Usually a second gap instead of a tooth. The specially designed sensor element detects this deviation and thus enables the position to be determined.