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 digital power amplifier system includes means providing a signal having predetermined characteristics is digitally synthesized and applied as input signals to a digital symmetrical pulse width modulator. The digital pulse width modulated signals are amplified in a digital or switching power amplifier. The resulting signals are then passed through a tuning or filter circuit to produce an analog signal having the desired frequency and wave shape characteristics which is then applied to a suitable load device. In the thus provided amplification system all of the amplification is accomplished through digital circuitry with no analog influence until the amplified circuits are applied to the tuning or filter elements.

Abstract: A digital power amplifier system features an analog signal which is converted to a corresponding digital signal and is, in turn, applied as input signals in a digital binary format to a digital pulse width modulator. The digital pulse width modulated signals are amplified in a digital or switching power amplifier. The resulting signals are then passed through a tuning or filter circuit to produce an analog signal having a desired frequency and wave shape characteristics. The analog signal is then applied to a suitable load device. In the thus provided amplification system, all of the signal processing and amplification is accomplished through digital or power switching circuitry with no analog influence until the amplified signals are applied to the tuning or filter elements.

Abstract: A pot-core transformer with a magnetic shunt variable to add the function of a variable series inductor independent of the transformer.

Abstract: An arrangement for improving the performance of Class D pulse width modulated amplifiers which comprises circuitry for short circuiting turns on the output transformer during intervals between pulses and thus enabling extended linear control of the power output of said amplifier and protecting the amplifier against transients fed back from a load connected thereto.