There are three external wires of the electromagnetic sensor, two of which are power wires and one is signal wire; There are two external plug wire of magnetoelectric sensor, both of which are signal lines.
2, the difference of division of labor:
Electromagnetic sensor is an "active" sensor, which needs an external power supply; Magnetoelectric sensor is a kind of "passive" sensor and does not need external power supply.
3, the difference of working principle:
Magnetoelectric sensor is a kind of sensor which uses electromagnetic induction principle to convert the input motion speed into induced potential output, and can convert the mechanical energy of the measured object into an easily measurable electrical signal without auxiliary power supply.
The electromagnetic sensor is based on the principle of Hall effect. Under the Lorentz force, the electron flow of the bias current I shifts to one side when it passes through the Hall semiconductor, which causes the chip to generate potential difference and Hall voltage in the CD direction. It needs an auxiliary power supply to work properly.
Extended data:
Magnetoelectric induction sensor consists of two basic components:
1, a magnetic circuit system that generates a constant DC magnetic field. In order to reduce the size of the sensor, permanent magnets are generally used;
2. The coil, which is connected with the magnetic flux in the magnetic field, generates induced electromotive force.
The induced electromotive force is directly proportional to the change rate of magnetic flux or the relative motion speed of coil and magnetic field, so there must be relative motion between them. As a moving part, it can be a coil or a permanent magnet. Therefore, their structural forms, materials and structural dimensions must be reasonably selected to meet the basic performance requirements of the sensor.
Second, the electromagnetic sensor uses the principle of electromagnetic induction to achieve the purpose of speed measurement. It has the advantages of large output signal, good anti-interference performance, no need for external power supply, and can be used in harsh environments such as smoke, oil and gas, water vapor and so on.
When the magnetic gap changes due to the rotation of the speed measuring gear, the induced electromotive force is generated in the probe coil, and its magnitude is related to the rotating speed. The higher the rotating speed, the higher the output voltage, and the output frequency is proportional to the rotating speed. With the further increase of rotating speed, the loss of magnetic circuit increases, and the output potential is saturated. When the rotating speed is too high, the loss of magnetic circuit increases and the potential drops sharply.
References:
Baidu encyclopedia-magnetoelectric sensor
References:
Baidu encyclopedia-electromagnetic sensor
References:
Baidu encyclopedia-sensor