The heat source in this Stego element consists of a PTC element – a semi-conductor that adapts its output to the ambient temperature.
The PTC element has a high starting current and provides full output almost immediately.
The current then falls quickly and the element is thereafter self-regulating, meaning that the warmer the surroundings, the less output produced by the element.
The heating element is best installed in small enclosures so as avoid condensation or that the temperature falls beneath the minimum. These heaters are designed for permanent operation.