Hybrid stepper motors are small electrical motors with high torque production, compared with other electrical motors of the same size. Hybrid stepper motors are reliable in open-loop systems, in Sinusoidal mode, but with a drawback of high power consumption. The power consumption may be reduced by Field-Oriented Control, but this control mode requires a positioning sensor, adding size and cost to the system. This Master’s Thesis explores the possibilities of observer-based Field-Oriented Control on a two-phase hybrid stepper motor without using a positioning sensor, run on a microprocessor and executed during the interrupt scheduling routine, coded in C/C++.

The Master´s thesis deals with description of the influence of cobalt additive on positive electrode parameters for Ni-Cd accumulators. Trough the use of Electrochemical Quartz Crystal Microbalance are analysed the effects which decline effective life of positive electrode during accelerated cycling. Theoretical part describes important characteristics of Ni-Cd accumulators, the working principle and effects which are in progress on positive electrode during cycling. The next part deals with description of system EQCM and the pricnciples of doping active mass with cobalt additive. Practical part consists of EQCM system calibration and electrochemical measurements. The principal aim is detection of the influence of cobalt additve on active mass during cycling in different electrolytes. From the results of measurements is set the optimal amount of cobalt additive.

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