Abstract: A power control arrangement for controlling the power output of a plurality of resistive heating elements (9a, 9b) comprises a multi-position switch (S1, S2) for connecting the heating elements in series and in parallel, a zero voltage switch (4), AND-gate (5), clock pulse generator (6), shift register (7) and semiconductor device (8) such as a trail which cooperate to vary the duty cycle applied to the heating elements in both serial and parallel modes.

Abstract: An electric cooker having means for warning the user when one or more of the cooking surfaces is above a safe touching temperature comprises a glass ceramic cooking surface having one or more electrical heaters arranged on the underside of the cooking surface. A temperature monitoring device is thermally coupled with at least one of the one or more heaters and comprises an auxiliary heater, for example of PTC material, a thermally responsive device in the form of a thermistor, for example of PTC or NTC material, and a thermal buffer positioned between the auxiliary heater and the thermistor. A neon lamp or a filament lamp is provided for indicating when the thermistor is at or above a predetermined temperature.

Abstract: An energy regulator for a household heating appliance such as an electric cooker comprises an electronic controller for the cyclical control of the supply of electrical energy to a heating element and a switch for increasing the electrical energy supplied to the heating element to a preselected level and for a preselected time. The preselected time may be variable in dependence on the duty cycle of the controller, the duration decreasing from about thirteen minutes at low duty cycle to one minute or less at high duty cycle. Actuation of the switch may cause the electrical energy to be increased to substantially 30% of full heating power at low duty cycle rising to substantially 100% of full heating power at high duty cycle.