control system and apparatus for controlling current input to an electrical resistance element such as a seal wire . 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 as it is heated . the feedback mechanism monitors both the actual current passing through the wire , and the length of the sealing wire , and adjusts the current applied to the wire , responsive to those monitored inputs . the usage of the sealing machine is also monitored and the application and amount of current flowing to the wire is varied based on this usage .