AC-to-AC converter

An AC/AC converter comprising input terminals 20, 21, pairs of output terminals 30-35, a plurality of bridge arms 50, and a control unit 60. The bridge arms are connected in parallel to the input terminals and comprise a respective bridge arm for each pair of output terminals and a common bridge arm S7, S8. Each bridge arm comprises a pair of switches (e.g. 51, 52) and a node located between the switches (e.g. 53). Each pair of output terminals comprises a first output terminal connected to the node of the respective bridge arm 30, 32, 34, and a second output terminal connected to the node of the common bridge arm 31, 33, 35. The switches have a plurality of configurations for selectively connecting the output terminals to the input terminals in one of a plurality of arrangements. The control unit controls the switches to apply an alternating output voltage to the output terminals having a higher frequency than the input voltage. The control unit controls the switches such that, over each half-cycle of the input voltage, the switches transition between different configurations.