On 9/14/2013 12:43 AM, john/lori wrote: > Jim Brain wrote: >> >> That's fine, but I do think I can provide a pretty nice sine wave >> approximation to the transformer. Either way, my sticking point is >> the transformer selection. Any links to a suitable offering? >> >> Message was sent through the cbm-hackers mailing list >> > > The advantage of doing the DC > AC after bumping up the voltage > is that you can run the voltage converter at a much higher > frequency and use a much smaller transformer. > Also voltage drops will be a smaller percentage (if you're > doing eg PWM) I understand, but at some point, I'm just designing a PSU. I see lots of 5VDC @ 60W or 80W PSUs online for cheap, and anyone can buy one. That takes care of one voltage, if I the circuit can make the other. And the PSUs are CE and UL-listed, or at least some are, and they are switchers, so they can be plugged into anything 90V to 260V. > > How'd you get 5 Amps ? 9VAC RMS @ 1VA = 12.73V Peak @ 1A. Creating that from a single side PSU will require ~25VDC @ 1A That's 25W That's 5A @ 5V If I do as Bil suggests, and use a center tapped Xformer, then the voltage need only be 12.5V @ 1A for each half cycle, or 12.5W which is 2.5A Maybe it's 2.5A regardless, but AC is not my strong suit. Jim Message was sent through the cbm-hackers mailing listReceived on 2013-09-14 07:00:08
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