The astronomy guys often use small ac motors to drive telescopes These motors require very little current Many do this with very small dc to ac converters that they can change the frequency of the ac by small amounts. The simplest circuits use a small 110v to 12v ct transformer running "backwards" with constant current source to the center tap and switching the legs. There should be many variations found in a google search. One typical circuit is http://www.wvi.com/~rberry/cookbook/120vinv.gif w.. Harold Hallikainen wrote: > I have an application where I need to drive a diaphragm pump (like those > used in aquariums) from low voltage DC (battery). Here in the US, these > pumps are mechanically tuned to run directly off the 60 Hz line. A single > coil on a core moves an armature that has a couple magnets on it. The > armature moves back and forth at 60 Hz, vibrating the diaphragm. > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist