摘要 |
The invention relates to an electrical surface treatment device which is provided with an acoustic surface type detector with which a type of a surface to be treated can be detected during operation. According to the invention, the surface type detector delivers an output signal (uFT) during operation which is characteristic of the type of surface to be treated and which is determined by a value of a physical quantity of air vibrations reflected by the surface to be treated, which value is measured by a vibration detector of the surface type detector. In a special embodiment, the physical quantity is an amplitude, and the surface type detector is a vibration generator for generating air vibrations having a predetermined amplitude. The generated air vibrations preferably have a frequency of at least 15,000 Hz which varies within a predetermined range. In a further embodiment, the vibration generator generates the air vibrations intermittently, and the surface type detector is a parallel circuit through which a portion of the generated air vibrations can be directly guided to the vibration detector.
|