In embodiments, a capacitance is coupled to a source of electrical charge via a drain to source current flow path through a field-effect transistor. The capacitance is pre-charged by making the field-effect transistor selectively conductive in response to the gate-source voltage of the field-effect transistor exceeding a threshold. The difference between the gate-source voltage of the field-effect transistor and the threshold provides an overdrive value of the field-effect transistor. The gate of the field-effect transistor is driven with a variable gate-source voltage having as a target maintaining a constant overdrive value. Electrical charge is controllably transferred from the source to the capacitance via the drain to source current flow path through the field-effect transistor avoiding undesirably high inrush currents.