5.1 Further examination of electrical connections and discussion
of results
A current rating of 600A is the normal supply output from most power
welding machines. The Dynasty welding machine in the Tunnel at the
University of Southern Queensland (TUSQ) has a maximum current output 0f
700A at 60% duty cycle. Going beyond the maximum current limit is
practically beyond the capability of the available facility but for the
purpose of analysis, current flow up to 2000A will be used. Fig.4.3 and
Table 4.1 have shown that any tungsten diameter less than 8mm will not
produce a very effective temperature distribution for a 50mm diameter
heat shield of 2mm thickness. Here the 10mm diameter tungsten rod is
properly examined and heat transfer limitations explained.