The working principle of laser marking machine galvanometer
The principle of the galvanometer is:
Input a position signal, the swing motor (laser galvanometer) will swing a certain angle according to the conversion ratio of a certain voltage and an angle. The whole process adopts closed-loop feedback control, which is composed of five control circuits, including position sensor, error amplifier, power amplifier, position discriminator, and current integrator. The principle of digital laser galvanometer is to convert analog signal into digital signal on the principle of analog laser galvanometer. The scanning laser galvanometer is the core component of the marking machine, and the performance of the marking machine mainly depends on the performance of the scanning laser galvanometer.
The basic structure of the vibrating lens:
Composition: It consists of three parts: stator, rotor and detection sensor. Among them, the vibrating lens is a moving coil type (the rotor is a coil), the others are moving magnet type (the rotor is a magnetic core), and all the vibrating lenses are permanent magnets as the magnetic core; The mirror is a grating ruler detection sensor. Capacitance sensor is a small change in the capacitance of the detection sensor when the motor swings, and the change in capacitance is converted into an electrical signal, which is fed back to the controller for closed-loop control. The grating ruler sensor measures the actual deflection angle through the grating ruler, which is converted into an electrical signal and fed back to the controller for closed-loop control. The moving coil type is basically not used because the rotor is a coil, and the coil is relatively large and has a large moment of inertia, which is not conducive to fast response. Because the hollow cylindrical core is tightly mounted on the rotating shaft, the moving magnet type is small in size and small in inertia, so the fast response performance is very good.
The basic requirements of the controller:
Because the laser marking machine relies on the cooperation of X and Y vibration deflection, the light is reflected to the work surface for precise engraving. The control of the galvanometer is open-loop controlled by the computer. Therefore, the requirement must be linear, that is, there is a linear relationship between the input signal and the deflection angle. Because the galvanometer is a fast and precise machine, it is required that the acceleration be as large as possible from one working state to another, so that the marking time is infinitely small.
