OK - So I was having my windshield replaced and the company had a interesting method of generating A/C power on the service truck. Instead of using a inverter, they had a DC motor turning an A/C generator. I have also seen this set up on a locksmith truck? Is this just old school method of generating A/C. The system is a bit larger then an inverter, but their must be some advantages to it? I know they use it large scale in rural areas to get 3-phase A/C to run irrigation pumps.