Is the DC BIAS source 20A DC or 120A DC? Shouldn’t it be an AC source?

The DC-Bias current source provides 20A DC. However, multiple units can be connected in parallel. A master unit with a control interface is combined with several slave units to achieve up to 120A DC.

The DC-Bias source is used to magnetize the core of an inductor, shifting the operating point on the saturation curve of the core. This allows saturation effects to be measured and sets a hysteresis core into a defined state. Since the bias current remains constant, the (AC) measurement signal can be superimposed with the DC-Bias current without interference. With a hypothetical AC bias, such interference-free superposition would not be possible, and the measurement signal would have to be cleaned in a complex manner.

Tags: