I'm still on the hunt for a cheap method of getting ac onto the grid.  Here's a rectifier which seems close.  Those of you that actually know what the heck you're talking about might give me some advise.  Yes, I have enquired about other units on Ebay but this one looks pretty good.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=130357875469&_trksid=p2761.l1259

I emailed the seller about the quality of the DC out and got this reply:


Am I to presume that the voltage out will be close to the voltage in and only uppy-downies are taken away?

Casey

Well the picture of the 3 phase rectifyer has no sign of any filtration, so it will have some ripple.
Single phase AC looks like this:




Single phase rectified DC looks like this(large ammount of ripple):




3 phase rectified DC looks like this:



Since 3 phase has two more phases(4 more positive going rectified peaks), it fills in the valleys seen on single phase rectified DC.

Single phase rectified can be made to look like this.  It takes a large filter capacitor to charge during the peak and carry the voltage output across the valley.  Note the sawtooth waveform as the cap discharges between the rectified peaks.  The larger the DC current draw, the larger the cap needed to maintain output voltage stability.