The main objective of this paper is to present an academic example of a PD controller applied to teach position control design of a DC-motor to automatically adjust a potentiometer. This adjustment is focused on to solve the maximum power transfer objective in a linear electrical circuit. This design involves the use of the extremum seeking algorithm. To support our proposal, numerical simulations and mathematical modelling of the main problem statement are programmed. (C) 2016, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.