Apparatus including a DC-DC converter that applies a variable voltage to an inductive load, such as a fan motor. The converter has a low-frequency high dynamic output impedance and applies a variable voltage from its output to the inductive load. A transient limiter, such as a capacitor, is connected in parallel with the inductive load to minimize the amplitude of transients generated by the load during the reception of the variable voltage from the converter. The converter has a low frequency of operation to inhibit the generated transients from being extended to a DC power source connected to the input of the converter. This prevents the transients from being applied to other circuits served by the DC power source. The fan may be used to provide cooling for the apparatus of which the DC-DC converter is a part.