There is always a need for more effective ways to store energy in order to reduce the human impact on the environment. One step on the way can be the use of flywheels as kinetic energy storage devices. Low frictional losses are essential for a flywheel to be effective. To minimize these losses active magnetic bearings (AMB) can be used to keep the shaft centered instead of the more conventional ball-bearings. AMBs use actuators and a fast control system that needs correct and noise-free measurement data of the shaft position and the current in the actuators to work properly. This thesis explains the process of constructing power electronics and a current measurement system for active magnetic bearings (AMB). The focus of the thesis is on how to minimize noise in the circuits, including practical considerations on circuit design and theoretical explanations of the origin of noise in electric circuits. In addition there are discussions on factors to consider when designing a PCB and the importance of choosing the right component for the right application. Finished PCB-designs for both power electronics and current measurement along with specifications of the circuits and calibration data is presented. The finished circuits works well and have low noise levels and high reliability.