Improvements relating rectifier circuits

A power adaptor comprising an input for connection to an AC power supply, an LCL series-parallel resonant circuit, and a rectifier circuit adapted to receive an alternating current voltage from the LCL series-parallel resonant circuit and provide an output having a rectified output voltage that is suitable for driving a load,

• the rectifier circuit comprising input terminals adapted to receive an alternating current voltage, and output terminals adapted to provide an output having a rectified output voltage,
• the rectifier comprising a diode bridge in which the diodes are each adapted to be by-passed by a low-impedance path on activation of an associated electronic switching device,
• wherein the rectifier circuit is adapted to control activation of one or more electronic switching devices, such that the flow of current relative to one of the output terminals is in one direction only.