Origin of step-up
Examples from the Web for step-up
It was attached to a step-up transformer that converted the current to 230 volts.
The transformation from a relatively low voltage to the high one is effected by means of what is called a step-up transformer.Every-day Science: Volume VI. The Conquest of Nature|Henry Smith Williams
The former is called "step-up" while the latter is a "step-down" transformer.Physics|Willis Eugene Tower
Barely touched 'em—current something less than a thousandth of a micro-ampere on a million to one step-up.Skylark Three|Edward Elmer Smith