Design of a Digitally Controlled Inductor-Less Voltage Multiplier for Non-Thermal Food Processing

Abstract—For non-thermal food processing systems utilizing an underwater shockwave, a digitally controlled voltage multiplier is proposed in this paper. The proposed voltage multiplier based on Cockcroft-Walton voltage multiplier (CWVM) has a bipolar structure. Unlike the conventional CWVM, the output voltage of the proposed multiplier is expressed by sum of the output voltage of positive and negative voltage multiplier blocks. Therefore, the number of stages of the proposed multiplier is about a half of that of the conventional CWVM. Furthermore, by utilizing high-low side drivers and a microcontroller, the diode switch of the proposed multiplier is driven by high-speed rectangular pulses. For these reasons, the proposed multiplier can achieve not only high voltage efficiency but also high speed operation. The validity of the circuit design is confirmed by theoretical analysis, simulation program with integrated circuit emphasis (SPICE) simulations, and experiments. The simulation results show that the settling time of the proposed voltage multiplier is less than 1/400 of that of the conventional CWVM. Furthermore, the experimental results show that the proposed voltage multiplier can improve voltage efficiency more than 21% from the conventional CWVM when the input voltage is 10V@60Hz and the output capacitor is 10μF.