On the Performance Analysis of the Microprocessor Based DC Voltage Calibrator

A microcontroller-based architecture of a DC voltage calibrator is presented in the paper and its performance is analyzed. The voltage calibrator is used as a basic measurement, test and adjustment technique for setting and checking measurement instrumentation. The voltage provided is used to achieve optimal performance of the device or process under test. The proposed calibrator is built around the PIC 18F452 microcontroller, using its PWM output signal generator facility. Both 8 bits and 10 bits resolution have been used and studied along this work. The advantages of using a microcontroller are: the possibility to display useful information (number, duty cycle, and voltage), communication with a computer and easy operation with buttons. The experiments revealed also the importance of the used components (for example, by changing the output operational amplifier with a quality one, it was possible to reduce the output residual voltage from 39 mV to 0.9 mV). Aspects regarding errors and their correction are analyzed. The designed calibrator can be used for the calibration of measuring instruments, in other measurement applications and for educational purposes.