Does a universal motor run better on flat DC as opposed to pulsed DC?
Pulsed DC voltage from a single phase bridge rectifier will mean that the current in the feild and hence the armature will be pulsing to some extent .The total inductance would have to be infinite to make the current waveform pure DC.The pulsing current will cause more motor losses than pure DC like a battery.But the losses are lower than a straight 230 VAC supply .