Abstract: An electric synchronous motor having a stator (10) with electric windings (14) and a rotor (16) which comprises a spindle (20) and a magnetic core (22), wherein the core (22) is formed by a number of annular magnetic discs (21) piled on the spindle (20) and having a length-to-diameter ratio exceeding 3. The discs (21) are insulated electrically from each other by layers of an inorganic material (17), such as an aluminum foil layer which is oxidized on both sides, and are axially clamped between shoulders (23, 24) on the spindle (20) to a high prestress level for obtaining a high bending strength, i.e. a higher coefficient of elasticity, of the rotor (16) as a whole.

Abstract: The invention relates to an electric control arrangement intended for use with object detecting systems, which include, inter alia, a light source (2) intended for transmitting light beams in a direction in which an object (3) to be detected can be expected to appear, at least one receiver unit (4, 5) for receiving light beams reflected by a detected object, and electrical and/or electronic devices for evaluating and detecting the presence of the object in response to variations that occur in the received reflected light beams as a result of relative movement between the object (3) to be detected and light beams (2a) transmitted by the light source.