Abstract: In an electrochromatic, transparent layer system comprising at least one electrochromatic layer (2), two electrodes (3, 5) separated by a hydrogen ion supplying layer which simultaneously is a hydrogen ion storing layer (4), there is located, seen in the direction of light incidence through the layer system, a further hydrogen ion conducting layer (6) (e.g. of SiO.sub.2) behind the electrode (5), behind which a further electrode (7) is arranged. The electrode (7) is capable of oxidizing hydrogen diffusing from within the system into hydrogen ions. For this purpose, a protective voltage is applied between electrode (5) and electrode (7) such that the third electrode (7) forms the positive pole.

Abstract: A housing package for the encapsulation of electrical components. The package comprises a base plate and a cap which encapsulate the electrical components. Electrical leads are lead through the base plate. The package is provided with a coating which increases the solderability of the electrical leads and increases the corrosion resistance of the housing.