Abstract: In a radiant heating unit, an insulating support for carrying a radiant heating resistor is molded or pressed using a granulation of expanded clay materials, particularly expanded mica or vermiculite. The granulation is compressed and bound in a blank by a mineral binder, particularly water glass, and the heating resistor is positively secured in the moulded granulation by embedding parts of the resistance wire forming the resistor, in such a way that the resistor is in part free of the insulating support on the front. The heating resistor can be embedded during production of the insulating support or can subsequently be pressed into the support. The insulating support of the heating unit is low in weight and easy to manufacture, has optimum electrical and thermal insulating properties and has very good strength, whereby the heating unit has a long service life.

Abstract: A radiant heating element for heating a glass ceramic plate carries on a circular insulating support heating elements in the form of wire coils fixed thereto, which are arranged in the form of two parallel spiral paths. Two separately switchable heating conductors are successively arranged in one spiral path, while the third heating conductor is positioned alone in the other spiral path. The heating conductors have different power levels and can be switched to different power stages by a seven-timing switch.