Embedded system for measurement of small electric input power

The contribution deals with measurement of low electric input power for research purposes in the machinability of materials. Requirements for measurement are high accuracy and high sensitivity. An analog device with differential measurement was designed and constructed. This approach measures only changes of the input values instead of their high input values and thus increase the sensitivity. The proposed solution uses only analog circuits and analog multiplier of the effective voltage and current. The device was subsequently checked in the lab environment and gradually modified. The results obtained from measurements with developed analog device showed insufficient accuracy. The new goal is to reconstruct the analog device to a digital one with a microcontroller