HEAT-RECOVERABLE LAMINATED HEATER WITH PTC LAYER OPERATING ABOVE SWITCHING TEMPERATURE

摘要

The invention relates to electrical devices in which a PTC element is used to control the temperature of the device. In the devices of the invention, a PTC element is associated with a heatsupplying means which supplies a controlled amount of heat to at least part of the PTC element after it has reached its switching temperature. The devices are particularly useful when in the form of laminates, for example, heat-recoverable laminates which will recover when current is passed through them.