Power conversion apparatus

An electrical apparatus comprising:

• a motor having at least one switched phase winding and configured to drive an impeller, wherein the at least one switched phase winding is switched at a frequency greater than 2 kHz;
• and
• a power conversion apparatus for converting power from an alternating source to dc, the power conversion apparatus comprising;
• an input stage for receiving power from the alternating source, which input stage includes an input filter,
• a rectifier for rectifying the alternating signal,
• a capacitor for storing energy from the rectified signal, and
• an output for outputting power from the rectifier and the capacitor to the motor,
• wherein the at least one switched phase winding receives power from the output, and wherein the capacitor is configured such that the voltage across the capacitor has a ripple voltage which is at least 85% of the nominal peak rectified voltage of the source during each cycle of the alternating source.