Implementation of a class D amplifier in a galvanometric system for industrial laser marking applications

El.En. S.p.A. is one of the world’s leader in the production of lasers, with products that cover a wide variety of application fields, such as medical, industrial, art restoration and many others, all completely realized inside the company. For products in the industrial field, beam deflection management is extremely important, since it affects their operating speed, precision and dimensions. This system consists of one focusing lens and two mirrors, each controlled by an electronic board and subsequently actuated by a brushless motor known as galvanometer. The aim of this thesis work was to understand the controlling board behaviour, study its class AB power output stage and develop an alternative power output stage centered around the use of a class D amplifier, with subsequent analysis of pros and cons between the two solutions. The main advantage carried by this research is the difference in theoretical efficiency between amplifiers of these two classes; while the former has a maximum efficiency below 78.5%, the latter has a 100% maximum efficiency if ideal switching MOSFETs are considered, and around 90% for the best realistic cases. The second purpose of this work was to start the process of unbinding the production of the controlling board from the AB amplifier currently in use, which the manufacturing company, Texas Instruments, has recently deemed obsolete, stopping its fabrication.