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.

So, in this application, I need to run the pump on DC. Ideas I'm
considering are:

1. Rewind the coil to have fewer turns and a center tap. Have a PIC drive
transistors that alternately ground one end of the coil or the other with
the center tap going to + supply.

2. Rewind the coil to have fewer turns without a center tap. Connect one
end to + supply, the other to a single transistor to ground that is
switched.

3. Electrically resonate the existing coil using a circuit similar to that
on page 4 of http://www.edn.com/contents/images/21705di.pdf ("Sine-wave
step-up converter uses Class E concept") where the inductor is the coil in
the pump.

Any ideas?

THANKS!

Harold


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