a d . c . to d . c . converter power supply having two substantially independent regulated outputs . a pulse width modulator converts input d . c . to a . c . having a variable frequency and a variable duty cycle . the a . c . is applied to a transformer having two secondary windings for separate d . c . outputs . one of the secondary windings feeds a rectifier having a capacitor input type filter and means for regulating the output voltage by controlling the duty cycle of the pwm . the other secondary winding feeds a rectifier having a choke input type filter and means for regulating the output voltage by controlling the frequency of the pwm .