Abstract: A device for displaying an electrical signal of the periodic and/or synchronizable type.

Abstract: A portable electric radiant heater comprises an insulative housing having a control area and an open front heating area. A hollow fired clay pipe system is disposed in the heating area in serpentine fashion and arranged to radiate heat through the open front. The clay pipe system comprises a plurality of hollow cylindrical pipe segments having a plurality of hollow protuberances extending therefrom. The pipe segments are interconnected together to form a continuous passage extending the length of the pipe system. An electric resistance heating wire extends centrally through the continuous passage in spaced relation to the surfaces defining the passage. The ends of the wire extend into the control area and are connected to a power supply means therein controlled by a thermostatic control having a sensing element enclosed in a clay cylinder disposed in heating area below the heat radiating pipe system.