Abstract: A voltage tester for the graduated display of a voltage applied to two test tips includes a circuit arrangement composed of a parallel connection of three series circuits whereby a PTC-resistor, an antiparallel connection of two light-emitting diodes, and voltage drop resistors are contained in two of the series circuits. Two Zener diodes connected oppositely to one are also contained in the second series circuit, and the third series circuit is composed a glow lamp and voltage drop resistors. The components of the voltage tester are accommodated in a handle connected by a cable to a second handle which a current limiting resistor. Preferred embodiments of the voltage tester and a preferred embodiment of the manufacturing method therefore are proposed.

Abstract: A sensor element arrangement for a pyrodetector has a concave mirror with a sensor element arranged at a focus of the concave mirror and further sensor elements arranged laterally therefrom. Electrodes of both polarities are present on each side of the film, these electrodes being respectively separated from one another by quasi-meander-like, metal-free strips which engage into one another in the form of hook portions. The electrodes on the upper side reside opposite corresponding electrodes on the lower side for the formation of the sensor elements, and these electrodes are connected to one another at edge regions by connection lines. The sensor element arrangement together with the film and the connection lines is surrounded by a retaining frame which is insertable into the mounting of the concave mirror in centered and adjusted fashion.

Abstract: A sensor element arrangement for a pyrodetector has a concave mirror with a sensor element arranged at a focus of the concave mirror and further sensor elements arranged laterally therefrom. Electrodes of both polarities are present on each side of the film, these electrodes being respectively separated from one another by quasi-meander-like, metal-free strips which engage into one another in the form of hook portions. The electrodes on the upper side reside opposite corresponding electrodes on the lower side of the formation of the sensor elements, and these electrodes are connected to one another at edge regions by connection lines. The sensor element arrangement together with the film and the connection lines is surrounded by a retaining frame which is insertable into the mounting of the concave mirror in centered and adjusted fashion.

Abstract: A device for determining the rotational speed of a rotating component, in particular of a brake disc (1) of an automotive vehicle brake, the brake disc (1) containing recesses (2) shaped at preferably regular distances and lying opposite to a probe. A contact element (5) is provided as the probe which is adapted to move into abutment on the brake disc (1) and which, when overriding each recess (2), will interrupt an electric circuit comprising an evaluation circuit.