The following chart presents a comparison between Roller type Regulator and Thyristor Controller:

Roller type Regulator There is no wave form distortion at any load. Higher power factor of more than 0.95 is achieved. Electrical waveform is like moving a wheel. For 50% rated voltage, the diameter of wheel is reduced accordingly, i.e. magnitude for a wave is decreased. The system is simple and can be repaired and maintained by simple mechanic. The cost of spares is very negligible. Overall losses are less.

Thyristor Controller There is wave form distortion. The power factor is comparatively lower between 0.5 to 0.9. It is like cutting the wheel by 50% and then moving the wheel, i.e. waveform is cut at full magnitude. The system is sophisticated and needs specially trained Electronic Engineer to repair and maintain. The cost of spares parts is very high. Overall losses are more.

Why the Regulator is Superior to Thyristors in Rectifier?
In plating application, our regulator is better and we are adopting technology used in Germany and Europe. Other manufacturers of rectifiers have shifted to thyristors because they have to use sliding carbon brush type regulators. They claim that thyristor controlled rectifier has less losses than a regulator. They compare thyristor with sliding carbon type regulator.

We strongly stress that their claim is not true. We use vertical coil type rolling carbon regulator. In our regulator the rollers move on both side of the coil to give ± 440v or ±254v output. Our rectifiers are designed in Q connection in which the regulator current is half the line current so losses are less and life is much more.