Magnetic rotational speed sensor, reliable performance, rapid response
Adapt to crankshaft, camshaft speed measurement of high reliability requirements
Working air gap: 0.5 ~ 1.5mm
Output signal: sine wave output
The connector can be used to lead the wire to provide customers with a more flexible installation program

What is the rotational speed sensor ?
The rotational speed sensor is a sensor that converts the rotational speed of the rotating object into a power output. The speed sensor is an indirect measuring device and can be manufactured by mechanical, electrical, magnetic, optical and hybrid methods. According to the different forms of signals, the rotational speed sensor can be divided into two kinds of analog and digital.



working principle:
Most of the output pulse signal (approximate sine wave or rectangular wave). For pulse signal speed measurement methods are: Frequency integral method (that is, F / V conversion method, the direct result is voltage or current), And frequency algorithm (the direct result is the number).
In the automation technology, the rotation speed measurement more, And the linear velocity is often measured indirectly by the rotational speed. The DC tachogenerator can turn the rotational speed into an electrical signal. Tachometer requires a linear relationship between the output voltage and the speed, And requires the output voltage steepness, time and temperature stability.

Tachometers can generally be divided into two kinds of DC and AC. The rotary speed sensor is in direct contact with the moving object. When the moving object is in contact with the rotary speed sensor, the friction force drives the roller of the sensor to rotate. A rotating pulse sensor mounted on the wheel sends a series of pulses. Each pulse represents a certain distance value, which can be measured line speed. Electromagnetic induction, in the rotation of the shaft to install the gear, the outer side of the electromagnetic coil, The rotation is due to the clearance of the teeth, Get the square wave to change the voltage, and then calculate the speed.
Rotary speed sensor and moving objects without direct contact, the impeller blade edge attached to the reflective film, When the fluid flow drives the impeller to rotate, the impeller rotates once every one turn of the fiber, Produce an electrical pulse signal. The speed can be calculated from the number of pulses detected.

Speed sensor features:
High sensitivity High reliability Long life long trigger distance
The signal is triggered by an iron (soft) magnetic material
Can achieve long-distance transmission of anti-electromagnetic interference ability
Good impact resistance and shock resistance

classification
Laser type:
Main functions and features
Princeton Optics is a world famous optical instrument; PR-870 is the use of laser reflection principle, to obtain the rotor rotation signal, Can measure the rotor speed. Features a high resolution, Distance, wide range of practical, wide frequency response, high reliability. Built-in zoom shaping circuit, the output is stable amplitude of the square wave signal, to achieve long-distance transmission.

Magnetic type:
Aerodynamic vibration HZ-860 magnetic speed sensor, Can convert the angular displacement into electrical signals for the counter count, As long as non-contact can measure a variety of magnetic materials such as: Such as gears, impellers, orifice (or groove, screw) disc speed and linear speed. Sensors have: small size, strong and reliable, long life, no power and lubricants, etc., And the general secondary instrument can be equipped with.


Capacitive:
Capacitive sensors, there are two types of area change and medium change. The capacitive speed sensor consists of two fixed metal plates and a movable metal plate connected to the rotating shaft. The movable metal plate is in the position of the largest capacity, When the rotation axis is rotated 180 °, it is in the position where the capacitance is the smallest. The rate of change in the capacity of the capacitor is the speed. It is possible to obtain a measurement signal of the rotational speed by means of a DC excitation, an AC excitation, and an oscillation tank for constituting the oscillator with a variable capacitance. The medium change type is formed by embedding a movable plate having a high dielectric constant between two fixed electrode plates of the capacitor. The movable medium plate is connected with the rotation shaft, and as the rotation shaft rotates, The dielectric constant between the capacitor plates is periodically changed to cause a periodic change in the capacitance, The rate is equal to the rotational speed of the rotating shaft.


Variable Magnetic Resistance:
It belongs to variable magnetoresistive sensor. Variable magnetoresistive sensor of the three basic types, inductive sensors, transformer sensors and eddy current sensors can be made speed sensor. Inductive speed sensor is widely used, it uses the magnetic flux changes produce induced potential, The magnitude of its potential depends on the rate at which the flux changes. This type of sensor according to the structure is divided into open magnetic circuit and closed magnetic way two. Open magnetic circuit speed sensor structure is relatively simple, The output signal is small, not in the vibration of the occasion to use. Closed magnetic circuit speed sensor mounted on the shaft by the external gear, internal gear, coil and permanent magnet. Internal and external gears have the same number of teeth. When the shaft is connected to the measured shaft to rotate together, due to the relative movement of the inner and outer gears, a magnetoresistive change is generated, and an alternating current induced potential is generated in the coil. Measured the size of the potential can be measured the corresponding speed value.