Abstract: A heated bedcover containing an electrical heating element therein is provided with an integrated solid state control circuit which functions providing control over the heating element both for comfort control so as to maintain a desired heat output from the heating element and to also provide protection against overheating conditions in the blanket.

Abstract: An electrical heating apparatus protected against an overheating condition and a temperature sensitive electrical sensor for the use therewith are disclosed. The electrical heating apparatus includes an electrical heater for generating heat in proportion to the amount of electricity flowing through it, and it provides essentially all the heat for the apparatus. An electrical sensor is disposed in a thermally responsive relationship to the electrical heater. The electrical sensor includes a coextruded pair of spaced flexible plastic conductors and a coextruded flexible temperature sensitive electrical impedance material having predetermined temperature coefficient impedance characteristics along its entire length. The temperature sensitive material is in electrical contact with the flexible conductors and controls the flow of electricity between them.

Abstract: An electrical heating apparatus protected against an overheating condition is disclosed. It includes an electrical heater and an elongate heat sensor disposed in a thermally responsive relationship. The heat sensor consists of a single conductor having positive temperature coefficient electrical impedance characteristics continuously along its entire length. The electricity flowing through the electrical heater is controlled in response to a signal from the heat sensitive conductor.

Abstract: An electrical heating apparatus, and particularly a bedcover preferably in the form of a blanket, protected against an overheating condition and in which electrical current flow through a heating element is controlled by a pair of gate controlled bidirectional semiconductor switches electrically connected to one another in series and in back-to-back orientation. The gates of the semiconductor switches are connected through a temperature sensitive capacitor which triggers the semiconductor switches from a conductive to a nonconductive state in response to the sensing of an overheating condition.

Abstract: An electrical heating apparatus, and particularly a bedcover preferably in the form of a blanket, protected against an overheating condition and in which electrical current flow through a heating element is controlled by a pair of gate controlled bidirectional semiconductor switches electrically connected to one another in series and in front-to-front orientation. The gates of the semiconductor switches are connected through a temperature sensitive capacitor which triggers the semiconductor switches from a conductive to a nonconductive state in response to the sensing of an overheating condition.

Abstract: An electrical heating apparatus such as an electrically heated bedcover protected against an overheating condition by an overheat protective circuit which utilizes a pair of solid state switching devices in the heating element circuit. The solid state switching devices are so connected that should one switching device fail in a shorted or closed mode, a second switching device will be in the circuit to control the heating element and provide normal protection against an overheating condition. The solid state switching devices are employed in a manner which permits the use of relatively small light weight temperature sensors in the form of positive temperature coefficient devices such as PTC resistors, which avoids the need for using relatively bulky bimetallic thermostatic switches as are conventionally employed for sensing overheating conditions.