---------- > From: Mike Smith > To: PICLIST@MITVMA.MIT.EDU > Subject: Re: [slightly OT] power transistors/H-bridges > Date: September 16, 1997 00:46 > > Was going to ask if you were going 3 phase. You playing with > frequency a lot too? There MUST be a reason aircraft systems run at > 400Hz - one suspects weight is one of the factors, and that would > certainly help anything solar... Yes, weight is a big reason, the transformers needed for 400hz are much lighter and smaller for the same rating 60 hz transformer. I believe this is the biggest reason, wreaks havoc on anything audio on a plane, blocking 60hz isn't that bad, blocking 400 hz, well just takes away some of the more common notes! TTYL