Electrical converter including gain enhancing means for low gain transistors

An electrical converter for supplying electrical power to a load from a d.c. source comprising:

• semi-conductor switching means for converting a direct input current to an alternating current;
• and
• an output transformer means fed with said alternating current for changing the magnitude of an output voltage with respect to an input voltage, wherein the semi-conductor means includes transistor means comprising a pair of transistors connected for mutually exclusive on and off conditions of conduction, each transistor of that pair being connected to a saturable drive transformer in a configuration which provides for switching in response to saturation of the drive transformer which includes at least a portion of primary windings connected respectively in series with the main current emitter collector circuits of the transistors of that pair, and having at least a portion of secondary windings connected to respective control electrodes of the transistors of that pair to provide current feed-back to a drive branch of the circuit connected to a control electrode of said transistor means said current feed-back comprising a means for increasing the response of the transistor means to drive signals derived from the input current and for providing a forced D.C. gain, thereby enabling a lower gain transistor means to be employed for a given minimum input voltage from the source, and wherein a voltage feed-back winding of the output transformer means is connected in the main current circuit of the transistor means in a configuration to provide voltage feed-back in the main current circuit in a sense to curtail the current in said main current circuit.