d.c. to d.c. converter power supply with dual regulated outputs

Claim 1

A d.c. to d.c. converter type power supply comprising, a pulse width modulator for converting input d.c. power to a.c. power having a waveform with a variable frequency and a variable duty cycle; a transformer having a primary winding and at least two separate secondary windings, said primary winding receiving a.c. power from said pulse width modulator; means including a first rectifier connected to one of said transformer secondary windings and a capacitor input type filter connected to said first rectifier for converting a.c. voltage induced in said one secondary winding to a first d.c. voltage output; means for converting a.c. voltage induced in the other said secondary winding to a second d.c. voltage output, including: a second rectifier connected to said other secondary winding; an inductor input type filter connected to said second rectifier, said filter having first and second output terminals through which current is supplied to a load and across which said second d.c. voltage appears as a potential difference; shunt-type voltage regulator means connected between said first and second terminals for diverting current from said terminals, said regulator means including a source of reference voltage; means for comparing said second d.c. voltage with said reference voltage; and variable impedance means responsive to said comparing means for controlling current flow through said regulator means; means providing a first signal related to said first d.c. voltage output for controlling the duty cycle of the output wavefrom of said pulse width modulator; and means providing a second signal related to said second d.c. voltage output for controlling the frequency of the output waveform of said pulse width modulator.