Abstract: A differential transformer is used as a feedback sensor for generating an error signal sensed at the face of an element of a sonar transducing array. This error signal is used to correct the excitation signal to the transducer to correct both phase and amplitude errors in the vibration of the radiating surface of the transducer. In this way, the transmitting beam pattern for the sonar array is improved. The differential transformer is capable of sensing the mechanical motion of the transducer radiating surface without being affected by a strong electric or magnetic field. By using a separate differential transformer sensor and processing circuit for each transducer in the array, electrical cross-talk between the individual elements of the array is eliminated.

Abstract: An inverter for producing A.C. from a source of D.C. electric power. The power circuit includes a power transformer with the current flow through the two halves of the primary winding 16 being controlled by a pair of power MOSFETs. A gate driver circuit which includes a driver transformer produces control signals which are substantially 180.degree. out of phase across the center tapped secondary winding of the driver transformer. A pair of fast-off, slow-on coupling circuits consisting of a diode connected in parallel with a resistor couples gate control signals to the gates of the power MOSFETs. Each coupling circuit is effectively in series with one of a pair of current limiting off-time setting resistors, the latter being connected in series with the two halves of the primary winding of the gate driver circuit control transformer.

Abstract: A pair of MOSFET power transistors are connected in a push-pull configuration to drive a tapped transformer and a load. A pair of diodes and an energy coupling circuit containing a capacitor and resistor in parallel bias the transformer primary in such a manner as to limit transients in a nonconducting MOSFET when the other MOSFET is conducting, aided by a drop in voltage at an inductor (ferrite bead) network which develops at the moment of MOSFET transistor conduction. This is due to a momentary change in the impedance ratio.