Constant Voltage Transformer

Constant Voltage Transformer (CVT) or Ferroresonant Transformer (Ferro) is a non-linear transformer, which passively provides a regulated voltage output through an electromagnetic phenomenon called ferroresonance (where the term ferroresonant transformer was derived). Ferroresonance is associated with the behavior of iron cores while operating near a point of magnetic saturation, wherein the core is so strongly magnetized that further variation in the input voltage results in little or no increase in magnetic flux.