V.Experimental ResultsThe realizati

V.Experimental ResultsThe realization of analogue input circuits and the logic circuits contains commonly used components. The microcontroller is of the type ATMEL AVR ATmega128. USB serial communication line makes use of the integrated circuit FT232RL isolated from the microcontroller by optocouplers. The Ethernet for LAN is based on the integrated circuit ENC28J60. Its connector is isolated from the cable by a transformer. The instrumentdisplays the necessary information on an LCD display with the resolution 128 x 64 pixels. The display BG12864 with two controllers KS0108 has been used.The software has been developed for the microcontroller and for the PC. The software for the microcontroller has been written in the environment WinAVR GCC.Measurements of the parameters of the constructed instrument showed very low delay of both comparators in case the same signal was connected to both inputs. The error of the preliminary phase shift measurement in the range from 0.1 V to 3 V and in the frequency range from 30 Hz to 3 kHz has been less than 0.8o. New measurements were carried out using new analogue shaping circuits and a RIGOL DG1022 2 Channel Function/Arbitrary Waveform Generator with the possibility to set a phase shift between the two output signals. The measured results for four values of the signals frequencies, namely 50 Hz, 500 Hz, 3 kHz, and 5 kHz are in Figure 4 to Figure 7, respectively. The values of the input signals were all four combinations of 30 mV and 2 V.