This disclosure refers to a method for confectioning resistors that each comprise a PTC ceramic plate and metallic electrode layers covering opposite faces of the ceramic plate, said method comprising the following steps: measuring an electrical resistance of a resistor to be confectioned by applying an electrical potential to one of electrode layers such that an electric current flows from one of the electrode layers through the ceramic plate to the electrode layer on the opposite face of the ceramic plate, comparing the measured resistance to a target resistance, and removing, if the measured resistance is lower than the target resistance, a section of at least one of the electrode layers. This disclosure also refers to such a resistor and a heating device comprising such resistors.

The present invention relates to a PT heater and, more specifically, to a PTC heater which: mechanically fixes a heating element, a terminal, an insulating layer, and a heat-radiating unit, which constitute the PTC heater, by bending a fixing projection of a hook structure formed at a heat rod; and further has an auxiliary fixing protrusion capable of fixing the position of the heating element so as to increase the adhesiveness between the PTC element and the heat-radiating unit, thereby enabling performance to improve and facilitating assembly through the heat rod.

A heat-generating element for an electric heating device includes a heating element casing which comprises a casing element formed from a ceramic material and a casing mating element formed from a ceramic material. The two casing elements bear against each other in a sealing manner and enclose, in a sealing manner between each other, a PTC element and conductor tracks. The conductor tracks bear, in an electrically conductive manner, against the PTC element and are assigned different polarities for energizing the PTC element. The heating element casing carries contact strips connected in an electrically conductive manner to the associated conductor tracks. At least one of the conductor tracks is formed by an electrically conductive element which is provided with through holes and which, in a height direction of the conductor track, comprises discrete points of support that bear against the PTC element and one of casing element and casing mating element. The present invention further relates to an electric heating device with at least one heater casing with a heat-generating element of the type described here that is arranged in a circulation chamber with a heating element casing joining at least one PTC element and contact strips energizing the PTC element as a structural unit. The heat generating element has the contact strips electrically connected to the PTC element projecting over itself. A partition wall separates the circulation chamber from a connection chamber of the heater casing. The contact strips of the PTC heating element protrude through the partition wall and are exposed and electrically connected.

A high-voltage heater for a motor vehicle for heating a coolant is disclosed. The high-voltage heater includes at least two flat tubes that are flowable through by the coolant and at least one heating element. The at leas two flat tubes and the at least one heating element are alternatingly stacked on top of one another in a stacking direction to form a stack. The at least one heating element is connected at least to one of the adjacent flat tubes in the stack in a heat-transferring manner.

A PTC heating element comprises at least one PTC element and two conductor paths which are assigned to different polarities and which are electrically conductively connected to the PTC element and are provided with connection elements for the electrical connection of the PTC element. The PTC heating element has improved heat discharge due to the provision of an electromagnetic shielding which is formed from a fluid-permeable metal structure and which surrounds the PTC element and the conductor paths.

The description relates to a vehicle heating system having at least one heat transfer device through which air can flow to be heated and at least one heating device which is attached to the heat transfer device and which each involves at least one heating element arranged between two contact plates, said heating element being held by a positioning frame which is attached to one of the contact plates. The contact plates of the heating devices are each held in a positioning frame to which they are attached.

The description relates to a vehicle heating system having at least one heat transfer device through which air can flow to be heated and at least one heating device which is attached to the heat transfer device and which each involves at least one heating element arranged between two contact plates, said heating element being held by a positioning frame which is attached to one of the contact plates. The contact plates of the heating devices are each held in a positioning frame to which they are attached.

A heating roller includes a cylindrical member and a winding. The cylindrical member has a cylindrical body forming first and second sides along an axial direction. Plural wiring holes penetrate the cylindrical body along the axial direction and are each open on the first and second sides. The winding has a conductive wire penetrating the wiring holes. The conductive wire extends in opposite directions through each two adjacent wiring holes and is connected to a power source. Alternatively, the heating roller includes two windings each having plural conductive wires penetrating the corresponding wiring holes, wherein the conductive wires of one of the windings are connected to the positive and negative terminals of the power source at the first and second sides respectively, whereas the conductive wires of the other winding are connected to the negative and positive terminals of the power source at the first and second sides respectively.

An electric heating device includes a housing with a partition wall which separates a connection chamber from a heating chamber for emitting heat. At least one heating assembly housing projects from the partition wall in the direction of the heating chamber. The heating assembly housing supports at least one PTC element and strip conductors in an electrically insulated manner A housing wall projecting from the partition wall and delimiting the connection chamber and/or the heating chamber and/or the heating assembly housing is connected to the partition wall by material bonding, which may be by induction soldering. Also disclosed is a method of making an electric heating device.

An electrical heating device for a motor vehicle, which includes at least one heating element and which includes at least one printed circuit board, the printed circuit board having at least one contacting area for establishing an electrical connection between the heating element and an energy source, the heating element having a plurality of PTC heating elements, which are electrically conductively connected to each other by a contact element, the contact element of the heating element being disposed at a distance from the contacting area, an electrically conductive connection between the contact element and the contacting area being established with the aid of a plurality of conductor strands.