| 摘要 |
A heating cable and associated heating blanket. The heating cable comprises conductors extending along the length of the cable separated by a separation layer. The conductors and separation layer may be coaxial. The conductors are connected at one end of the cable in series such that if the conductors are connected at the other end of the cable to respective poles of a power supply equal currents flow in opposite directions through adjacent portions of the conductors, substantially eliminating electromagnetic radiation from the cable. One conductor has a positive temperature characteristic and the separation layer has either a negative temperature characteristic or melts at a predetermined threshold temperature. Power may be modulated in response to variations in the resistance of the positive temperature co-efficient conductor. Power to the cable may be terminated in the event of current flowing through the separation layer exceeding a predetermined threshold. |
