In contrast to traditional heating elements for conventional 12V onboard power supplies, TDK's recently-released EPCOS PTC heating elements are designed for the considerably higher voltages found in EV batteries. The rated voltages of these heating elements range from 200 to 500V, producing surface temperatures of up to 250°C. Depending on design, these heating elements are suitable for safe operation at up to 1000V.
Whereas cars with combustion engines can use waste heat for heating the passenger compartment, electric vehicles require electrical heating. In electroceramic components with Positive Temperature Coefficient (PTC) characteristics, the electrical resistance increases as a function of the rising temperature, creating a self-regulating effect.
The flow of current increases not only the temperature of these ceramic elements, but also their resistance, thereby limiting the current and establishing a stable equilibrium. Depending on customer requirements, the EPCOS PTC heating elements can be manufactured in a variety of geometries and with different electrical and thermal properties.