Ferroresonant Transformer Design Program

Ferroresonant Transformer Design Program (FERRO) designs a wide range of constant voltage ferroresonant transformers. FERRO designs both two-coil and three-coil (harmonically compensated) type transformers.

Ferroresonant Transformer
Ferroresonant Transformer Design Software

FERRO is used to design:

  • DC power supplies

  • Line stabilization and power conditioning

  • UPS output regulators

  • Battery chargers

  • Controlled ferros

Notable Features

  • Determines resonant capacitance
  • Accommodates any lamination shape
  • Accomodates C-Cores
  • Permits designs with round, square, and rectangular wires as well as foil.  Either copper or aluminum conductors can be entered
  • Calculates temperature rise of primary coil and for secondary coil separately 
  • Determines shunt air gap
  • Data is entered by source files


  • Modes of operation are
    • User enters core – Ferro selects wires
    • User enters core proportions – Ferro determines core and wires
    • User enters core and wires – Ferro determines turns and temperature


  • Other design considerations present in Ferro
    • Capacitive reflection factors
    • Harmonic current effects
    • Core material permeability effects
    • Input power factor
    • Method of handling square wave inputs
winding data transformer design
DC Primary Transformer Design Software