Abstract: Ignition systems of the kind used to ignite a difficult-to-ignite fuel oil by using energy stored in a capacitor at a breakdown for creating an ignition arc at the electrodes of a resistive arc probe, having a semiconductor resistive film across spark electrodes of the resistive arc probe, designed to preclude interference of contaminants with conduction of an ignition arc across an established current path between the electrodes of the resistive arc probe. An air gap and a resistive arc probe are connected in series. A first high voltage power supply develops a first direct current voltage across a capacitor, which is supplied as a voltage across the air gap and the resistive arc probe. A second high voltage power supply supplies a second pulsed voltage across the air gap and the resistive arc probe, wherein the second pulsed voltage is substantially higher than the first direct current voltage, and the second pulsed voltage jumps the gap of the air gap and thus initiates an ignition arc.