Back when inverters were expensive, heavy, and generally junk, me and my wife set out on vacation. I had a mountain of work to do, and thought to myself that I could set up a PC in the back of the van and knock out some work while it was her turn to drive.
Here's the part important to you -
I simply constructed a DC-DC converter that so that I got about 150V regulated DC from our 12V system. It worked great!
Why? Because almost everything uses a switching power supply, and the first thing that a switching power supply does is rectify the incoming AC and make it DC for a DC-DC converter. What a sweet deal, no pure since wave needed!
But, there is a complication. Since you are working with high voltage DC rather than AC, the original fuses don't work properly. Should a fault happen, they like to carry an arc. So, you're forced to give up your 25 cent fuse and replace it with a larger one of the same current rating, but made to break DC. They used to cost about $4.00.
- Mike