A power supply for an elevator drive, comprising a voltage input, a comparator for comparing the input voltage with a predetermined threshold, a transformer having a primary winding and a secondary winding connected to the elevator drive; where the transformer has a single tapped primary winding and wherein, when the input voltage exceeds the predetermined threshold input, the comparator output causes power to be supplied to the primary winding via one of an end of the winding or the tapping of the winding, and when the input voltage is below the predetermined threshold, input power is supplied to the primary winding via the other of the end of the primary winding and the tapping of the winding.