An electric heating device a housing with a partition wall which separates a connection chamber from a heating chamber for dissipating heat and from which at least one PTC heating element with a heating element casing protrudes in the direction toward the heating chamber. At least one PTC element and conductor tracks, electrically connected in the connection chamber for energizing the PTC element with different polarities and connected to the PTC element in an electrically conductive manner, are supported in the heating element casing an insulated manner. For improved support of the PTC heating element, a holding element, engaging around the heating element casing, is connected to the partition wall on its side facing the heating chamber and is connected to the heating element casing. Also disclosed is a method for the manufacture of such an electric heating device.

Provided are a structure, a planar heater including the same, a heating device including the planar heater, and a method of preparing the structure. The structure includes a metal substrate, an insulating layer disposed on the metal substrate, an electrode layer disposed on the insulating layer, and an electrically conductive layer disposed on the electrode layer, wherein a difference in a coefficient of thermal expansion (CTE) between the metal substrate and the insulating layer is 4 parts per million per degree Kelvin change in temperature (ppm/K) or less.

A layered heater is provided that includes a sensor layer formed by a layered process having a plurality of independently controllable zones, and a resistive heating layer disposed adjacent the sensor layer. In one form, the sensor layer is formed of a material having a relatively high temperature coefficient of resistance (TCR) and the resistive heating layer is formed of a material having a relatively low TCR.

The present invention involves calibrating a control system to enable resistance-based control of a heat tracing circuit, that includes characterizing a piece of heat trace to determine a relationship between resistance and temperature, allowing for more precise control. Also described are different methods for practical resistance-based control of a heat trace system. Further described are several methods to monitor heat trace: including methods to enhance monitoring capabilities using a system operating model; comparison to historical operating data; and inclusion of information from external sources. Also provided is a method by which a piece of heat trace of unknown length and power factor can be controlled using the resistance-based method when other system information is available.

It is one object of the present invention to provide a thermal history estimation apparatus, a thermal history estimation method and a thermal history estimation program that can estimate variation in thermal history within a plane of a sheet heated by a heating apparatus. The thermal history estimation apparatus includes a first acquisition unit that acquires color information on a sheet plane heated by the heating apparatus, and a first estimation unit that estimates information on variation in thermal history on the sheet plane based on the acquired color information.

A heating pad with a thermostatic control circuit coupled to a resistance heating element. The resistance heating element and an acrylic based polymer adhesive are glued between polyester film layers. The film layers and heating element are contained with a plastic sleeve. The thickness and properties of the polyester film and adhesive forms a fuse. The adhesive delaminates the polyester film at excessive temperatures causing the resistance heating element to sever thereby creating an open circuit that halts operation of the heating pad. The thermostatic control circuit includes a hysteresis circuit that compares analog signals across two thin film resistors to provide a control signal to a power controller to selectively vary the power output to the heating element. The thermostatic control circuit is an integrated circuit board disposed within the fused plastic sleeve.

A system for detecting and controlling temperature of a layered heater is provided that includes a layered heater having in one form a substrate, a first dielectric layer disposed on the substrate, a sensor layer disposed on the first dielectric layer, a second dielectric layer disposed on the sensor layer, a resistive heating layer disposed on the second dielectric layer, and a third dielectric layer disposed on the resistive heating layer. An overtemperature detection circuit is provided in one form that is operatively connected to the resistive heating layer. The circuit includes a resistor, the sensor layer, and an electromechanical relay in parallel with the sensor layer. The sensor layer defines a material having a relatively high TCR and the resistive heating layer defines a material having a relatively low TCR such that a response time of the control system is relatively fast.

Exemplary embodiments are directed to thermally driven actuator systems including a thermally driven element and one or more heating elements coupled to and in thermal contact with the thermally driven element. The thermally driven element can be capable of being selectively reconfigured in shape based on a thermal strain or temperature driven phase change. The one or more heating elements can be configured to selectively and independently apply heat to one or more of a plurality of different regions of the thermally driven element to selectively raise a temperature or temperatures of the selected region or regions of the thermally driven element to selectively reconfigure the shape of the thermally driven element.

A heating pad with a thermostatic control circuit coupled to a resistance heating element. The resistance heating element and an acrylic based polymer adhesive are glued between polyester film layers. The film layers and heating element are contained with a plastic sleeve. The thickness and properties of the polyester film and adhesive forms a fuse. The adhesive delaminates the polyester film at excessive temperatures causing the resistance heating element to sever thereby creating an open circuit that halts operation of the heating pad. The thermostatic control circuit includes a hysteresis circuit that compares analog signals across two thin film resistors to provide a control signal to a power controller to selectively vary the power output to the heating element. The thermostatic control circuit is an integrated circuit board disposed within the fused plastic sleeve.

A heating element includes an electrically insulating layer; resistive layer formed of a positive temperature coefficient material; and an electrically conductive layer disposed between the electrically insulating layer and the resistive layer and including a first bus and a second bus that is spaced apart from the first bus, the resistive layer electrically connecting the first bus and the second bus. The electrically insulating layer, the electrically conductive layer, and the resistive layer are stacked to form a lamination and the lamination having a thickness and a width and length extending orthogonal to the thickness. The lamination may have slits extending through the thickness thereof and along a portion of the length thereof. Terminals may be connected to the buses and arranged to provide a counter current flow pattern across the lamination. The lamination may be used in a warming device and in connection with a patient warming system.