A switched mode power supply

The supply has two parallel-connected signal paths with switches (16) switchable between conducting and non-conducting states for generating a pulsed d.c. signal from the input signal (UE) or a derivative signal, output filters (20) for generating the output d.c. voltage from the pulsed d.c. voltage signal, a rectangular wave generator with a constant duty cycle of 50 per cent operable independently of the output voltage and an inverter.