With an engine driven welder, today’s models contain internal combustion engines in order to use the mechanical energy of the engine and turn it into electrical energy, which can then be used by the welder. This is a very popular type of welding power supply today. Most of the time, these welders tend to look very much like a small generator, and that’s very similar to what they really are. Instead of supplying electrical power to a house though, it is supplying it to the welding tool. Some of the high quality welders are able to run for a long time and use less fuel than models of the past, which means cost savings for you.