Abstract: An actuator (A) for a component (2), comprising at least one defined stop position, in particular to a brake component actuator of a yarn brake (B), for a selective braking of a running yarn (Y) which actuator has a drive element (D) for linear or rotational adjustment of the component (2). Said actuator is provided with at least one stop device (C). The stop device (C) consists of an additional body (Z), supported in a displaceable manner on a motion damping device (F, G, H). The actuator (A) in the yarn brake is a reversible motor, suitably a magneto-electric motor (M) for rotational movement. An additional body (Z), supported in a displaceable manner on a motion damping device, is provided in each stop device, at which the yarn brake is to stop. During a linear adjustment of the component (2), the mass (m1) of the additional body (Z) matches the mass (m) of the displaced parts.

Abstract: A yarn processing system, e.g. a yarn feeder comprising a housing in which at least one semiconductor component is arranged on a printed circuit board. The semiconductor component lies on a heat conducting body which is in the form of at least one prolongation of the housing that extends through the printed circuit board up to the semiconductor component.