1. In a generator for producing a predetermined duty-cycle square wave with a natural oscillation period in response to a binary signal, wherein said binary signal is variable as to the preiod during which it is at its first level, and said period may be greater than or less than the period of one cycle of natural oscillation of said oscillator, the combination of a source of dc voltage, said source having one terminal connected to circuit ground, an oscillator comprised of two switching transistors connected in a push-pull multivibrator configuration between two terminals to two primary windings of a transformer having an output winding across which said square wave is induced, and a regenerative feedback winding to each of said switching transistors, said transformer being comprised of a core having a square-loop flux versus mmf characteristic, whereby said switching transistors conduct alternately when dc voltage is applied to said switching transistors from said source to induce said alternating signal in said output winding, one of said two terminals of said oscillator being connected to said circuit ground, said oscillator including means for operation with a minor-loop flux excursion in said transformer with flux saturation of one polarity at the beginning of one cycle of said oscillator and flux at a lower level of opposite polarity at the end of one cycle of said oscillator during steady state operation, means connected to one of said switching transistors to cause it to conduct first whenever dc voltage is applied to said switching transistors, whereby said alternating signal always starts with a half-cycle of predetermined polarity, said predetermined polarity being selected to turn said electronic power switch on, control means responsive to said binary signal for applying dc voltage to said switching transistors when said binary signal is at a first predetermined level, and removing said dc voltage when said binary signal is at a second predetermined level, thereby providing a duty cycle generator for controlling the on and off condition of said oscillator, said control means being comprised of first and second cascaded transistors each having a base, an emitter and a collector, said collector of each being couped to said source of dc voltage and said emitter of each being connected to said circuit ground, the base of said first cascaded transistor being connected to receive said binary signal and the collector of said second cascaded transistor being connected to the other of said two terminals of said oscillator, whereby said oscillator is turned on while said first cascaded transistor is on, and turned off while said first cascaded transistor is off, and said minor-loop flux excursion means being comprised of a third transistor having an emitter connected to the collector of said second cascaded transistor through a resistor and capacitor in parallel, a base connected to said source of dc voltage, and a collector connected to a center point between said two switching transistors connected in a push-pull multivibrator configuration such that, when said second cascaded transistor is turned off, said third transistor is turned off to remove operating bias voltage from said two switching transistors to assure that both turn off and remain off, whereby said oscillator has the potential of very high operation frequency during steady state operation.