The stabilizer transformer is an AC regulator made of the magnetic separation structure based on the principle of ferromagnetic resonance. Generally, it is believed that the stabilizer transformer is evolved from the electromagnetic voltage regulator. The primary winding of the stabilizer transformer has a set of reversed phase coils, which form a reverse reactance. The designed neutralization value of the winding and the main line takes the value of 220 V as central voltage.
When the input voltage changes, the size and property of power supply (perceptual or capacitive) in parallel resonant circuit change according, so that the core will enter into the state of saturation or deeper saturation, making the flux of the core in each half cycle almost constant. Therefore, the output voltage maintains a constant value, playing a role as voltage stabilizer.
There is also a compensation winding at the output side of the stabilizer transformer. Its polarity is opposite to the auxiliary winding, which is used to compensate the influence of the input voltage variation on the output voltage. This is because the magnetization saturation curve of the core is not an ideal line. When the input voltage increases, the output voltage will increase as well so as to compensate.