Abstract: A circuit which limits current to a first value until a predetermined time has elapsed, then permits the current to rise to a second, acceptable value. The current limiting can be carried out during a predetermined time interval by a biased semiconductor switch. Subsequent to the current limiting time interval, the semiconductor switch can be saturated enabling the current to increase.

Abstract: A circuit which limits current to a first value until a predetermined time has elapsed, then permits the current to rise to a second, acceptable value. The current limiting can be carried out during a predetermined time interval by a biased semiconductor switch. Subsequent to the current limiting time interval, the semiconductor switch can be saturated enabling the current to increase.

Abstract: A three phase voltage regulator system uses a transformer having primary, secondary and tertiary windings for each phase which are closely magnetically coupled to each other and are connected to provide a four wire (wye) three phase output on three hot lines with a neutral line, and a three phase input which is also wye connected, but where the neutral need not be connected to an input neutral line. The voltage across each primary phase winding is regulated by a series connected regulator circuit. The regulator circuit may derive voltages from the respective tertiary winding which either bucks (subtracts from) or boosts (adds to) the input voltage so as to maintain the primary winding voltage substantially constant. A controller which is responsive to the output voltage from the secondary windings controls the regulators and responds to output voltages of their respective phases.