Abstract: The electrical unit has a printed circuit board (10) supporting the circuit, which includes a power component (11) which generates heat. In order to dissipate this heat from the power component, the power component rests on a heat conductive layer (13) which in turn is applied to the upper side (12) of the printed circuit board. This heat conductive layer further has a portion of the lid (18, 19) of the housing resting on it, which serves as a cooling area. Alternatively, the cooling area can be a free-standing cooling element. The heat transfer thus takes place via the heat conductive layer (13) to the cooling element (18, 19) so that the latter may be applied and formed independently of type and form of the power component.

Abstract: In order to provide protection against disruptive radiation and achieve good conduction of heat, a housing for control devices which has multiple parts is provided with a printed circuit board carrying power components and control elements with a peripherally extending lining of electrically and thermally conducting material. The printed circuit board is clamped between the housing halves in the region of the linings. The power components are contacted by the lining so as to be thermally conducting, while control elements which give off intensive disruptive radiation or are sensitive to such radiation are enclosed within connecting pieces projecting from the walls of the housing parts.

Abstract: By a special structure the conductor paths between connection prongs at one end of an electric circuit unit and circuit components located on two circuit boards are greatly shortened. The circuit boards are connected at their ends remote from the connector prongs by studs that releasably snap together while a flexible flat conductor makes connections between the two circuit boards. The two circuit boards are electrically and mechanically connected with separable parts of a plug connector each carrying at least one row of prongs projecting into a plug-in space of a receptacle body. One of these separable parts is integrated into a receptable body, which is provided with an aperture through which the other plug connector part can be slipped and locked into place after the boards have been electrically connected together at their far ends and the circuits have been checked.

Abstract: The invention relates to an apparatus for drying finely particulate solids in a carrier gas stream conducted along a helical path. The apparatus consists of an externally heated and cooled flow tube centrically surrounding a similarly heated and cooled inner body. Guide means helically arranged in succession in the flow direction are situated between the flow tube and inner body, and are formed as aerofoil-like curved or flat plates and are distributed over the whole length of the inner body. These guide means are designed as a self-supporting structure not secured to the inner body.

Abstract: A safety device is included in a circuit comprising a power source and a user device. The power source has one terminal connected to ground, as does the user device, with the safety device connected in a conducting path leading to the ground in the user device. In the event of an incorrect polarity connection between the power source and user device, a current path through the safety device and to ground is established.