Among other things, one or more techniques and/or systems are provided for varying a voltage applied to a radiation source of an imaging modality to vary an energy of emitted radiation. A power supply comprises at least two rectifiers, with a first rectifier being electrically separated from a second rectifier via a switching component. When the switching component is opened, the first and second rectifiers are effectively arranged in parallel, and when the switching component is closed, the first and second rectifiers are effectively arranged in series. The voltage applied by the power supply may be different based upon whether the rectifiers are arranged in parallel or in series, but the power output by the power supply may remain substantially constant regardless of the rectifier arrangement.
