A driver provides a current through a load circuit that includes an ionizable path. The driver includes an energy sourcing circuit, an ionization detector, a controller, and a pulse generator. The controller determines, in response to the detector and by trial and error, a respective quantity of energy for each pulse of a plurality of pulses to be generated. For each pulse of the plurality, the pulse generator receives the respective quantity of energy from the energy sourcing circuit, provides in response to the quantity of energy a respective voltage to ionize the ionization path, and provides the current through the load circuit.