Ferroresonant constant AC voltage transformer

A ferroresonant three-phase constant AC voltage transformer comprising:

• three magnetically permeable cores.
• first and second pairs of primary windings having first and second windings in each formed on each of said magnetically permeable cores,
• a pair of secondary windings formed on each of said magnetically permeable cores,
• two sets of three-phase input terminals and three output terminals,
• a first set of three input means each providing a self-inductive reactance effectively in series with a corresponding said second winding of a said first pair of primary windings formed on its said magnetically permeable core and a corresponding said first winding of another of said first pairs of primary windings formed on another of said magnetically permeable cores to thereby form a first set of primary phase circuit branches connected in a predetermined connection pattern to the three-phase input terminals of the first set,
• a second set of three input means each providing a self-inductive reactance effectively in series with a corresponding said second winding of a said second pair of primary windings formed its said magnetically permeable core and a corresponding said first winding of another of said second pairs of primary windings formed on another of said magnetically permeable cores to thereby form a second set of primary phase circuit branches connected in a predetermined connection pattern to the three-phase input terminals of the second set, and
• said first secondary windings of a said pair thereof each formed on its magnetically permeable core and each provided in series with a corresponding second secondary winding of another said pair thereof formed on another of said magnetically permeable cores to thereby form three circuit branches connected to said three output terminals in a selected one of star and delta connection patterns.

A ferroresonant three-phase constant AC voltage transformer comprising:

• three magnetically permeable cores each having leg parts mutually juxtaposed with leg parts of each of the other two magnetically permeable cores to thereby form three pairs of such juxtaposed leg parts,
• three primary windings each formed about a different one of said three pairs of juxtaposed leg parts,
• three secondary windings each formed about a different one of said three pairs of juxtaposed leg parts,
• three input terminals and three output terminals,
• three input means each providing a self-inductive reactance effectively in series with a corresponding one of said primary windings to thereby form three primary phase circuit branches connected to said three input terminals in a selected one of star and delta connection patterns, and
• said secondary windings each forming one of three secondary phase circuit branches connected to said three terminals in a selected one of star and delta connection patterns.

A ferroresonant three-phase constant AC voltage transformer comprising:

• three magnetically permeable cores each having leg parts mutually juxtaposed with leg parts of each of the other two magnetically permeable cores to thereby form three pairs of such juxtaposed leg parts,
• three pairs of primary windings having first and second windings in each, and with each of said pairs formed about a different one of said three pairs of juxtaposed leg parts,
• two sets of three-phase input terminals and three output terminals,
• three secondary windings each formed about a different one of said three pairs of juxtaposed leg parts,
• a first set of three input means each providing a self-inductive reactance effectively in series with a corresponding said first winding of a said pair of primary windings formed on its said pair of juxtaposed leg parts to thereby form a first set of primary phase circuit branches in a predetermined connection pattern to the three-phase input terminals of the first set,
• a second set of three input means each providing a self-inductive reactance effectively in series with a corresponding said second winding of a said pair of primary windings formed on its said pair of juxtaposed leg parts to thereby form a second set of primary phase circuit branches in a predetermined connection pattern to the three-phase input terminals of the second set, and
• said secondary windings each forming one of three secondary phase circuit branches connected to said three output terminals in a selected one of star and delta connection patterns.