Originally Posted by Brent Swain
I use a 100 amp dodge alternator, which I paid $25 for in an auto wreckers , driven by a 10 inch pulley off my main engine.I feed the field from the staring battery ,thru a toggle switch and a 50 watt 12 volt car headlight bulb, to reduce the input to something which wont fry the field windings. To avoid frying the diodes, I put a 120 volt, 60 amp light bulb betweeen the negative and positive output.
You need a lot of RPM , hence the 10 inch pulley. I once had a commercialy buiult welder which used a 3800 rpm wisconsin gas engne and still a 10 ich pulley. That was a lot of RPM! I control the output with the throttle.
I find I get about three years out of the internal diodes which come with the alternator. When they go, I use a much bigger set of external diodes in aluminiumn plates as heat sinks , which never get warm. Dont have the numbers with me at the moment ,but they are common. I have only done, stainless, steel and aluminiumn stick welding with it, but I understand the high frequency of this setup may work well with TIG or MIG.
I have built several anchor winches and stainless woodstoves with it , from scratch, in my cockpit ,while at anchor. The output from it also runs my 120 volt angle grinder and other 120 volt power tools.
I couldn't fit it in my engine compartment, so I made a removable panel on the side of the engine compartment to run a V belt thru, and mounted the alternator outside the engine compartment. I also mount my watermaker pump there.
Thanks Brent, I have considered it. One thing I really like about the premier power unit is that they've wired in a switch to flip between regular charging and welding. I know this crap ain't rocket surgery but I have no clue how they do that.
But also, how do you adjust it when you're welding? Just seat of your pants looking at the beads? I'm still a total newb and can't really tell what I'm doing yet. Definitely need some classes just don't want to go for a year to be a commercial welder