Making a chopper controller circuit

Abstract

I have made a demonstration of "control by power electronics" for the open house of the R&D Centre I am currently working for. The demonstration consists of a simple driver circuit that controls the gate of a power MOSFET. The electric current through the MOSFET drives a dozen dc fans.

The circuit was prepared on a breadboard so the viewers can assemble the circuit themselves. Interestingly, children who were much younger than I expected tried to assemble the circuit. Naturally they only obey the instructions without understanding what they are doing, but when the things were complete and I started measuring it, their faces suddenly became happy.

This demonstration is intended to be some sort of contribution to encourage more youngsters to be involved in science and technology. What I have learnt from this event was that it requires a great deal of patient efforts. It requires time and resources. Improving the education system by means of introducing competition would not work if enough resources were not provided.