Degree Name

BS in Electrical Engineering


Electrical Engineering Department


David Braun


The growth of sustainable energy requires many components to work in harmony creating one efficient and effective system. Sustainable energy generation that produces a DC current varying in voltage requires a subsystem to convert voltage to a practical and usable value. The DC to DC Buck converter converts high DC solar generated voltage to a 12V output. This Modular -Level power electronic (MLPE) device performs as a solar charge controller for small lithium ion batteries. Fluctuating voltage levels generated by Photovoltaic cells makes the solar controller a critical part of the solar system. Regulating the DC voltage allows safe and effective battery changing. The converter uses Pulse Width Modulation (PWM) to improve efficiency and longevity of the battery system [8]. The DC to DC converter receives 12V to 40V at a maximum of 1 amperes typical of portable solar applications. The step-down converter designed at the transistor and integrated circuit level uses PWM supplying constant voltage [3]. PWM controls switches (transistors) that enables or disables current flow via digital signals to control the step-down process. Inductors enable energy conservation in the circuit during on/off cycles. The size of the inductor determines the effectiveness and efficiency. The converter’s battery charging responsibility contains the most important performance criteria. Designed for charging lithium ion 18650 cells, this converter connects to compatible lithium ion charging stations. Development of the buck converter focuses on efficiency, magnetic design and voltage regulation. The project focuses less on charging cycles for the cells that charging docks handle.