A trick to get around this is to use a 24V transformer to buck the mains down to 216V. Add the voltage doubler after that and your DC is spot on.
You need a transformer that has a rated secondary current at least equal to the mains load current. Connect the primary across the mains supply and the secondary in series with the mains. If you get 264V out reverse the primary or the secondary (not both). This page <http://sound.westhost.com/articles/buck-xfmr.htm#s30> explains how it works and also shows a slightly better way of wiring the transformer that is slightly more efficient but outputs a slightly higher voltage. Read the warnings in the conclusion if you want to try this! Another thing to keep in mind when using a doubler is that they have quite a lot of ripple so you need lots of smoothing caps to keep the ripple low enough. Too much ripple can damage the caps or the rectifier in the VFD. On my lathe I use a 240->415V transformer and feed 415V single phase straight into the inverter. It works quite happily though again the ripple currents are much higher than it was designed to handle. So far I have had no problems but I never load it to it's full capacity of 7.5kw. Les On 21/10/2013 17:58, Kirk Wallace wrote: > Andy, by the way, I tried a Delon doubler on a 240VAC 3ϕ VFD from 120VAC > 1ϕ. I seem to recall the DC output was around 360VDC, but the VFD didn't > seem to mind. I was hoping to try the Delon on 240VAC 1ϕ, but it seems > the output would be around 720VDC, which would be significantly beyond > the expected DC voltage for 440VAC class VFDs. More work needed. > > http://www.digikey.com/product-search/en?x=16&KeyWords=493-8195 > http://www.digikey.com/product-search/en?x=16&keywords=FFPF20UP40S > ------------------------------------------------------------------------------ October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register > http://pubads.g.doubleclick.net/gampad/clk?id=60135031&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
