Disclosed is an electrical heating device for heating the interior of a vehicle, comprising a plurality of PTC heating rods each comprising ceramic PTC heating resistors, heat sinks for transferring heat from the PTC heating rods to an air flow, and a holder holding the PTC heating rods. The PTC heating rods are connected in series to an NTC heating rod comprising at least one NTC resistor, wherein the NTC heating rod is held by the holder.

A double-switching heater includes a double-switching PTC ink deposited on a substrate to form one or more resistors. The double-switching PTC ink has a first resin that provides a first PTC effect at a first temperature range and a second resin that provides a second PTC effect at a second temperature range, where the second temperature range is higher than the first temperature range. The substrate may be a flexible substrate or a rigid substrate, and may bedeformable to generate a three-dimensional structure. The substrate may be: polyester, polyimide, polyamide, polypropylene, thermoplastic polyurethane, fiberglass, cement board, carbon composite materials, polyethylene terephthalate, polyethylene, aluminum, steel, glass composite, molded plastic, high-density polyethylene or styrene ethylene butylene styrene.

A self-regulating far-infrared carbon fiber composite planar electrothermal material and manufacturing method therefor, where the material is composed of two reinforced insulating layers, two insulating layers, two self-regulating layers and a heating layer, is formed by high-temperature hot pressing, impregnation and curing, and further comprises a connecting terminal and a power supply lead. The connecting terminal is riveted on copper electrodes at two ends of the self-regulating far-infrared carbon fiber composite planar electrothermal material, and the power supply lead is snap-fitted on a wiring groove of the connecting terminal. The electrothermal material uses a three-dimensional conductive network with a stable physical structure of carbon fiber conductive paper, which effectively avoids unstable heating performance, short service life, and fire hazards that may be caused in the self-regulating planar heating material.

A substrate support for supporting a substrate in a substrate processing system includes a plurality of thermal elements. The thermal elements are arranged in one or more thermal zones, and each of the thermal zones includes at least one of the thermal elements. Each of the thermal elements includes a first resistive material having a positive thermal coefficient of resistance and a second resistive material having a negative thermal coefficient of resistance. The second resistive material is electrically connected to the first material. At least one of the first resistive material and the second resistive material of each of the thermal elements is electrically connected to a power supply to receive power, and each of the thermal elements heats a respective one of the thermal zones based on the received power. At least one ceramic layer is arranged adjacent to the thermal elements.

According to one embodiment, a heater includes an elongated substrate; a conductor that is provided on the substrate along a longitudinal direction of the substrate; and a plurality of resistance heating elements which are respectively disposed on the substrate along the longitudinal direction of the substrate, are electrically connected to each other in series by the conductor, and of which each resistance temperature coefficient becomes smaller as the resistance heating elements approach end regions in the longitudinal direction of the substrate.

A heating device for heating water has a carrier to which at least one heating element is applied, the heating element having one or more heating conductors which are connected one behind the other. The heating device has a flat dielectric layer which substantially covers the heating conductors or the heating element. An electrically conductive connection area is in each case provided on both sides of the dielectric layer with the same coverage. At least one of the connection areas is connected to a controller for evaluating a leakage current as current flows through the dielectric layer, and the heating element is connected to measuring means for monitoring a heating conductor current through the heating element. Both the leakage current and the heating conductor current are monitored over time and faults can be identified if there are conspicuous changes.

A safe heating circuit, comprising a PTC electric heating element; a first switching element, configured to switch on-off a power loop of the heating element; a first voltage acquisition circuit, configured to sample a first temperature voltage; an NTC element configured to receive a leakage current; a second voltage acquisition circuit, configured to sample a second temperature voltage; and a controller, configured to compare the first or second temperature voltage to a set temperature voltage and output the on-off signal, the second voltage acquisition circuit comprises a voltage divider circuit and a third current limiting circuit, and a second filter circuit; one signal input terminal is coupled to the second filter circuit to receive a sampling signal; and a current flow-in terminal of the third current limiting circuit is coupled to a power terminal, and a current flow-out terminal is coupled to the connection terminal.

Methods and systems for predicting at least one temperature along a fluid flow path of a fluid flow system having a heater disposed in the fluid flow path are provided. In one example, a method includes: obtaining at least one input, wherein the at least one input includes a setpoint, a mass flow rate, an inlet temperature, or a combination thereof; calculating a temperature associated with the heater based on a predefined model and the at least one input; and setting a value of the at least one temperature along the fluid flow path to the temperature of the heater.

The present invention relates to a method for detecting overheating of an electrical heating device comprising a plurality of resistive elements configured to be supplied electrically using a control signal by pulse width modulation according to a setpoint, comprising the following steps: detecting the setpoint, detecting the duty cycle (PWM_system; PWM_subsystem), defining a threshold value for detecting the duty cycle according to the setpoint, or a value of at least one parameter for monitoring an incidence of overheating, comparing the detected duty cycle value with the detection threshold value, and detecting an incidence of overheating when the detected duty cycle value reaches the detection threshold value. The invention also relates to a corresponding control unit.

A honeycomb structure made of ceramics, wherein the honeycomb structure includes: a borosilicate; and silicon particles doped with at least one dopant, the dopant is a Group 13 element or a Group 15 element, the silicon particles have a dopant amount (A) of 110.sup.16 to 510.sup.20/cm.sup.3, and the honeycomb structure has a silicon particle content (B) of 30 to 80% by mass.