Abstract: Power supplies are known, in particular power supplies under primary clock-pulse control, that comprise a closed housing for the primary and secondary circuits, and a forced-air cooling means to cool the heat-producing components of the circuits. A power supply is proposed in which additionally there is a ventilation conduit in communication with the air outside the housing to serve as a cooling medium. The cooling means also comprises at least one cooling-unit element, on which the heat-producing components are mounted, and a portion of said element projects into the ventilation conduit and is electrically isolated by insulating means.

Abstract: The DIN Standard VDE 160/01.86 involves specific requirements as far as the dielectric strength of electronic devices is concerned which are intended for operation at high-voltage networks. A guard circuit for the protection of capacitive loads is described. In this system, a current detector means is provided to detect the current flowing into the load and to emit a first blocking signal at least when the amount of the detected current exceeds a preset maximum value. A voltage detector means is provided to detect the voltage in the supply network and to emit a second blocking signal when the amount of the detected voltage exceeds a preset maximum value. A controllable switching means is provided which is so designed and in such controlled communication with the current and voltage detector means that the load will be isolated from the supply network as soon as at least one of the two blocking signals is applied.

Abstract: A rear wall for a standard housing, which housing is adapted for receiving electronic assemblies. The rear wall is provided by an enclosure in the form of a hollow body with mounting flanges for mounting the hollow body to one end of the housing so as to form a housing rear wall. A power pack for supplying power to the electrical assemblies is mounted in the hollow body so that heat may be transferred and carried off towards the outside of the housing. Ventillators and vent openings are provided in the hollow body to enable forced ventilation cooling of the power pack as well as to enable heat transfer from the housing interior. The mounting flanges are positionally located on the hollow body so that the formed housing rear wall is provided within the housing interior and the hollow body extends from the housing rear wall outwardly so as to partially project from the housing.