The Wayne Kerr 3265B, 25 A DC Bias Unit performs Component tests up to 125 A DC bias current. To evaluate components at high currents up to 125 A the 3265B DC Bias Unit is used with either the Wayne Kerr 3255B Inductance Analyzer or the 3260B Precision Magnetics Analyzer. When one DC Bias Unit is connected to either instrument up to 25 A of DC bias current can be set in steps of 25 mA with one unit. Additional DC Bias Units can be added in parallel such that with five units connected in parallel it is possible to set bias currents up to a maximum of 125 A DC. The instruments have a number of safety and protection features including a safety interlock system to protect the user against back EMFs. It is also fully protected against over temperature, excess voltage drop and sense lead failure.