On 9/24/06, Harold Hallikainen wrote: > I think the most efficient approach would be to use motors that are rated > for the battery voltage. Failing that, I suspect a bridge switcher driving > a transformer is the most efficient way to get a relatively high power to > a higher voltage. A typical boost converter (which I consider a form of a > "flyback converter") becomes impractical above 100 or 200 watts. > Flyback converter is not really derived from boost converter. But you are right that flyback converters are more suitable for power level below 200Watts. Boost converters are very often used as the front end of PFC (power factor correction) circuits and they are okay even at power levels more than 1kW. But again I think you are right it might be better to use a transformer isolated full-bridge converter for this kind of application. Eg: TI UCC3895 http://focus.ti.com/docs/prod/folders/print/ucc3895.html Regards, Xiaofan -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist