Original poster: "Mr Gregory Peters by way of Terry Fritz <twftesla-at-qwest-dot-net>" <s371034-at-student.uq.edu.au> Ed, I assume you have the resistor in parallel with the welder which is in series with the pole pig? Cheers, Greg Peters Department of Earth Sciences, University of Queensland, Australia Phone: 0402 841 677 http://www.geocities-dot-com/gregjpeters