The widely used Hall effect crankshaft position sensor is introduced below. The application of Hall effect crankshaft position sensor in automobile is of special significance, which belongs to solid-state semiconductor sensor. It consists of a permanent magnet and a magnetic circuit whose magnetic poles are almost completely closed, and a soft magnetic impeller rotates the gap between the magnet and the magnetic poles. The working principle of Hall effect crankshaft position sensor is that there is a gap on the soft magnetic impeller.
When the gap between the soft magnetic impeller leaves between the magnet and the magnetic circuit, the magnetic field between the magnet and the magnetic circuit is interrupted, because the soft magnetic impeller is a medium that can conduct the magnetic field. When the gap is between the magnet and the magnetic circuit, a magnetic field is formed between the magnet and the magnetic circuit. Therefore, the amplitude of the signal voltage obtained by the Hall effect crankshaft position sensor remains unchanged, while the frequency changes with the vehicle speed. The photoelectric crankshaft position sensor is composed of light emitting diode, phototransistor and shading disk.
It is usually installed in the dispenser. A signal generator consisting of two pairs of light emitting diodes and phototransistors is fixed on the bottom plate of the distributor. The distributor shaft is provided with a shading disc with an arc groove. When the optical disc rotates with the distributor shaft, the arc grooves alternately block the light from the light emitting diode to the phototransistor, so that the phototransistor is turned on or off, thereby generating a pulse signal. The number of arc grooves on the outer ring of the optical disc is the same as that of cylinders, and a pair of light emitting diodes and phototransistors corresponding to the arc grooves generate reference signals (NE signals) and rotational speed signals, so that the piston of each cylinder reaches the top dead center. There is only one arc groove in the inner ring of the optical disc, and the corresponding LED and phototransistor generate the reference signal (G signal) that the piston of the first cylinder reaches the top dead center. Electromagnetic speed and crankshaft position sensor.
The sensor can be divided into upper and lower parts; The upper part is the camshaft position sensor, which consists of a G rotor with convex teeth and two induction coils G 1 and G2, and is used to generate the reference signal (G signal) of the first cylinder top dead center. The lower part is divided into crankshaft position sensor, which consists of a Ne rotor with 24 convex teeth and an Ne induction coil, and is used to generate crankshaft angle signal. The G rotor is used to generate the reference signal of the top dead center of the first cylinder, and the ECU determines the top dead center position of the first cylinder according to G 1 and G2. Ne signal is a pulse signal with the same number of teeth as the Ne rotor, which is generated in the Ne induction coil every revolution of the crankshaft. The ECU determines the engine speed according to the ne signal received per unit time. These two wires are electromagnetic: check the resistance to judge whether it is good or not. One signal is positive and the other is negative. Three wires are Hall type: it is impossible to check the resistance. A power supply is mostly 5V. One signal is grounded. Check the signal waveform with an oscilloscope at work to judge whether it is good or not! Luxury car decoder can also be found out!