Οι σταθεροποιητές είναι ότι πρέπει για το κακής ποιότητας ρεύμα της ΔΕΗ. Το κακό είναι ότι πέφτει η απόδοση σε μικρά φορτία οπότε θέλει καλή επιλογή μεγέθους.
*An alternative method is the use of a type of saturating transformer called a ferroresonant transformer or constant-voltage transformer. These transformers use a tank circuit composed of a high-voltage resonant winding and a capacitor to produce a nearly constant average output with a varying input. The ferroresonant approach is attractive due to its lack of active components, relying on the square loop saturation characteristics of the tank circuit to absorb variations in average input voltage. Older designs of ferroresonant transformers had an output with high harmonic content, leading to a distorted output waveform. Modern devices are used to construct a perfect sinewave. The ferroresonant action is a flux limiter rather than a voltage regulator, but with a fixed supply frequency it can maintain an almost constant average output voltage even as the input voltage varies widely.
The ferro resonant transformers, which are also know as Constant Voltage Transformers (CVTs) or ferros are also a good surge suppressors, and it provides high isolation and an inherent shortcircuit protections.
It can operate with an input voltage range as wide as ±40% or more of the nominal voltage.*
http://en.wikipedia.org/wiki/Voltage_regulator