Abstract: A solid-state power transformer circuit is provided for converting the positive and negative periods from an AC input signal having a predetermined frequency and applied to an input of the circuit into a high frequency signal and, subsequently, converting the high frequency signal into a regulated output signal at an output of the circuit. A plurality of electronic optically-coupled switches are utilized for chopping the AC input signal at a chopping frequency. The switches are controlled by the oscillator of an integrated circuit to adjust the duty cycle of the switches. A filter, in the form of a pair of capacitors, is connected between the input and output to suppress the high-frequency voltage harmonics produced during chopping. The capacitors, in combination with other capacitive and resistive elements of the circuit provide a total separation impedance between the input and output of the circuit to electrically isolate the output from the input.