The motor operates directly off of house current at 60 cycles per second (signified by the sine wave in the upper right corner).

The electric current flows through thin wires around an iron core. The wire is wrapped around one side of the core, many hundreds of times.

Whenever the current reverses (60 times per second) the magnetic flux created by the current is reversed. This alternately pushes and pulls the armature.

The armature moves the diaphragm in and out directly. The valves are forced open and closed by the air pressure created by the movement of the diaphragm.

(This is a still representation and possibly also a low-resolution image of a pump which is fully animated in the CD-ROM version of this glossary.)