Abstract: A coupling circuit (30) connects two three-phase pulse width modulated (PWM) inverter circuits (16, 18), used in conventional manner to power a first load (12), in order to independently power a second load (32). In a preferred embodiment, the two PWM inverter circuits propel an armored vehicle, such as a tank, with one motor driving the right side, and the other motor driving the left side. The propulsion of the vehicle represents the first load. The second load is a pulse forming network (PFN), which PFN powers an electrothermal gun system carried by the vehicle. The coupling circuit includes a transformer (TA, TB, TC) and rectifier circuit (34) for each phase output of the PWM inverters. A primary winding (32) of each transformer is connected between corresponding phase outputs of the two PWM inverters. A secondary winding of each transformer is connected to a respective rectifier circuit. The output of each rectifier circuit is joined with the other rectifier outputs to charge the PFN.

Abstract: An electronic circuit for inhibiting overconduction of power transistors utilized in a switching mode and driven by a square wave signal of selected frequency. A reference voltage is utilized to compare the conduction of the transistors. The signal produced as a result of the comparison is utilized to control the base drive to that transistor through a logic circuit. Timing means is provided to delay the turn on or tuen off of the drive signal responsive to the comparison signal.

Abstract: A base drive regulator for a transistor operation in a switching mode comprising a series transistor regulator between the source of drive voltage and the base of the switching transistor and a diode with its anode element connected to the base of the series transistor regulator and its cathode connected to the collector of the switching transistor. The material used for construction of the switching transistor, series regulator transistor and the diode has similar electrical characteristics.

Abstract: A base drive inhibit circuit for positive and negative phase transistors of a switching amplifier. The circuit comprises a pair of comparators for comparing the voltage between the collector and emitter elements of the transistors with an appropriate reference voltage, and provides a signal to supply base drive voltage, when their associated output transistor is in a forward biased state and the level of reference voltage is less than the level of voltage between the collector and emitter. A logic control circuit supplies base drive voltage to one of the transistors when both a drive signal from an external source is in a proper polarity state and the output signal from the comparator indicates that the transistor is in a forward biased state.A timer is provided to delay base drive voltage to either transistor when the base drive signal is in a transition between polarity states.