A power supply circuit includes a matrix converter that converts a first to third input alternating current (AC) phases into a single primary phase, a transformer including a primary side electrically connected to the single primary phase, a rectifier electrically connected to a secondary side of the transformer, and an output voltage terminal electrically connected to the rectifier. The matrix converter includes first through sixth bi-directional switch pairs, and each of the first through sixth bi-directional switch pairs includes first and second uni-directional switches. When the third input AC phase is disconnected or short circuited, the second and the fifth bi-directional switch pairs are turned off, and, in each of the first, third, fourth, and sixth bi-directional switch pairs, one of the first and second uni-directional switches are turned on and the other of the second and first uni-directional switches are operated as a full-bridge phase-shifted converter.