Abstract: A pre-ionizing system in which the pre-ionizer elements are integral with the cathode insulating plate is provided. The cathode insulating plate includes a recessed region machined into the front surface into which the cathode fits, lying substantially flush with the insulator front surface. The back surface of the insulating plate contains a pair of slots running parallel to the long axis of the cathode. The pre-ionizing rods are located within these slots, the slots having sufficient depth to locate the rods approximately adjacent to the cathode. By maintaining the rods at ground, a capacitor is formed in which the insulating plate material between the rod and the cathode acts as the dielectric material of the capacitor. When a voltage pulse is applied, a capacitive corona discharge is formed which pre-ionizes the gases in the region near the cathode.

Abstract: A brushless DC motor with an adjustable timing feature is provided. The timing adjustment allows a specific motor's performance to be optimized by compensating for individual variations both in the characteristics of the rotor position sensors as well as in their locations. The rotor position sensors may be affixed to a heat sink within a portion of the motor housing. To improve the cooling efficiency of the heat sink at least a portion of the motor housing to which the heat sink is thermally coupled is cooled through either active or passive cooling. The rotor position sensors may be enclosed by a structure which improves their thermal and electrical isolation. A means of monitoring and controlling the speed of the motor is also provided.