Abstract: A sample tube includes a cylindrical wall and a first end and a second end. The first end of the sample tube is closed by a base, such that a sample-receiving space with a longitudinal axis is formed between base and cylindrical wall. The second end has a closure piece connected releasably thereto. A weight element is received inside the receiving space and is shaped and dimensioned in such a way that the weight element can rotate freely in the receiving space only about the longitudinal axis of the latter. The application further relates to a method and a device with which a sample located in the sample tube can be dispersed or homogenized by rotational movement of the sample tube.

Abstract: A controller is provided for driving a stepper motor with a magnetic rotor and at least one coil. The controller has a power stage for supplying the at least one coil with current, at least one analog Hall sensor for providing a signal as a function of the position of the magnetic rotor with respect to the Hall sensor, and a feedback line connecting the Hall sensor with the power stage to feed the signal of the Hall sensor back to the power stage.

Abstract: A controller is provided for driving a stepper motor with a magnetic rotor and at least one coil. The controller has a power stage for supplying the at least one coil with current, at least one analog Hall sensor for providing a signal as a function of the position of the magnetic rotor with respect to the Hall sensor, and a feedback line connecting the Hall sensor with the power stage to feed the signal of the Hall sensor back to the power stage.