K. S. Suresh Kumar is Assistant Professor, Department of Electrical Engineering, National Institute of Technology Calicut, Kerala. A product of IIT Madras, he has been teaching at NIT Calicut for the past twenty-four years. He handles courses on electric circuits, analog electronic circuits, pulse electronics, active filters, DSP, communication systems and power electronics. His research interests include active harmonic filtering, active power factor correction and flexible AC transmission systems. He consults in the area of energy auditing and conservation.