Abstract: A regulated DC to AC power converter of the switching type for providing AC power at a selected output frequency, e.g., 50 Hz, is disclosed. The converter, which eliminates the need for an inverter transformer, is switched at a switching frequency which is considerably higher than the output frequency, e.g., 10 KHz. Due to the high switching rate the converter filter can be designed with small and lightweight components to provide a desired pass band, which includes the output frequency and harmonics thereof, and provides sufficient attenuation for the switching frequency and its higher harmonics, so as to produce an output with very low ripple or waveform distortion. Due to the high switching frequency the output waveform can be regulated with a response time of a fraction of a cycle. The converter includes a modulator section with a unique arrangement to control the switching of the switches between their On and Off states.

Abstract: An AC power source characterized by the absence of a step-up output transformer is disclosed. The power source, which includes first and second output terminals across which a load is connected, is designed to provide AC power at a desired output voltage, e.g., 130v rms up to a desired current rating, e.g., 8 amperes. The source includes a first unit which includes a first voltage amplifier associated with positive and negative current amplifiers of substantially unity voltage gain, which provide power at the first output terminal up to the rated current at a voltage of 65v rms. Direct feedback is provided to the first voltage amplifier from the first output terminal, to which the load is connected. The source includes a second unit identical to the first unit, which includes a second voltage amplifier associated with positive and negative current amplifiers of substantially unity voltage gain, which provide power at the second output terminal up to the rated current at a voltage of 65v rms.