Voltage source for AC electroluminescent measurements

Alternating high voltage source for measurement of AC electroluminescent panels consisting of microcontroller, digital potentiometer, buffer with signal converter, amplifier with high voltage module, current limiter and power supply unit was developed and tested. The AC source is based on digital sine waveform generation, using the look-up table method. The generated sine waveform is furtherly amplified by AB class amplifier up to 260 Vpp. The voltage source constructed is connected to PC via USB interface. A simple testing program for the PC computer was also written. The test of the AC voltage source was performed by measurement of four layer AC electroluminescent panels in a setup consisted of PC computer, the voltage source developed, shunt resistor, optical fiber and spectrophotometer. The measurement of AC electroluminescent panel shows stable behavior of the source producing sine signal without apparently visible on the oscilloscope distortions of higher harmonics. The measured sample is of predominant capacitive character which is related to the strong influence of the dielectric layers.