| 摘要 |
Control system and apparatus for controlling current input to an electrical resistance element such as a seal wire (2). The system and apparatus of the present invention is a closed loop feedback modification to conventional systems, and takes advantage of the inherent expansion of the seal wire (2) as it is heated. When the seal wire (2) expands to a predetermined length, a switch (3) is triggered which interrupts at least a portion of the power supplied to the wire for heating. The interruption continues until the wire contracts to a length less than the predetermined length, whereupon the interruption ceases and heating of the wire resumes normal operation. <IMAGE> |
