Ferroresonant Transformers

MSI Ferroresonant TransformerThanks to the electromagnetic phenomenon known as ferroresonance, these transformers are also known as Constant-Voltage Transformers (CVT). A CVT regulates its secondary voltage typically within a few percent even when the primary voltage changes as much as 15-20 percent. Accompanying these transformers is a bank of capacitors. These capacitors are used to tune the output voltage of the CVT and are essential to its proper operation.


  • Input range +/- 20% of nominal voltage
  • Output regulation +/- 2% of nominal voltage
  • Power Ratings up to 5 KVA
  • Frequency of operation 50 and 60 Hz
  • Aluminum or copper windings