Supercapacitor Charging Technology with Digital Changes of the Duty Ratio

Abstract

An adiabatic circuit was designed for charging and discharging a supercapacitor stepwise. The duty ratio of the switching transistors is changed in a stepwise fashion and controlled by a microprocessor. The charging efficiency, that is the ratio between the work done by the power supply and electrostatic energy of the capacitor, is calculated from experimental results. The efficiency is 95% when the number of stepwise voltage is 32, which is consistent with the theoretical value.