In this thesis I will talk about development of a voltage generator with the possibility of selecting three amplitudes and three forms of the output signal, which is intended for internal use in the company.
The product of this project generates an output signal so that the microcontroller takes the points of sinus wave out of a table and multiplies them so that the correct amplitude is achieved. These values are then sent to the external DAC, amplified on the audio amplifier and further lifted on the transformer.
The choice between the voltages is done on the microcontroller, while others are taken care of by relays that connect the output to other elements that regulate the output signal. These elements are power diodes that cut off unwanted half-waves and resistors and capacitors that eliminate unwanted distortions.
In order to ensure that the output voltage during the operation of the unit is within the required limits, the feedback is formed by a voltmeter consisting of a voltage tracker, a precision polar rectifier and a Sallen-Key low-pass filter. The result is then sent through an external ADC to the microcontroller, which processes it and then corrects the amplitude at the output.
For the need of this unit, we have produced a printed circuit board and a program in C programming language which drives the proper unit operation via microcontroller.
Because I had successfully fulfilled all of the planning demands, the unit went into the everyday use.