Might also be able to just buy a commercial VFD (Variable Frequency Drive) This is about the smallest I've seen: http://www.newark.com/schneider-electric/atv12h037m3/ac-drive/dp/11R1086?CO= M=3DPower&Energy and the datasheet spec's 400hz as it's max... --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .