An alternative method of operation for the well known moving-coil voltage regulator is discussed, and its theory is treated on classical lines. In the new régime, the short-circuited coil is fixed, and the output is drawn from the moving coil, instead of vice versa. A comparison is drawn between this moving-secondary regulator, the moving-coil regulator and the induction-type voltage regulator, which serves to clarify certain basic points in transformer theory. Tests were made on a small laboratory regulator, specially devised for experimental purposes, and some discussion of these tests is included. The same regulator also enables a variety of other educational tests to be performed, the regulator being, in effect, a generalised transformer.