Abstract: An apparatus for ionizing air to remove particulate matter. The apparatus including an ionizer and a bracket for mounting the ionizer in a duct or enclosure. The ionizer includes a series of electrodes which span a portion of the duct. The electrodes are energized by a high voltage circuit and an ionic wind is created between the electrode and duct. The ionic wind sweeps particles in the air to the duct which provides a collector electrode. In another embodiment, a ring collector electrode is also provided for spanning the inner portion of the duct. The high voltage circuit includes a DC power supply, a high voltage transformer, a high voltage multiplier stage and a push-pull switching circuit. The DC power supply receives AC power and generates a DC output which is coupled to the primary of the transformer. The push-pull switching circuit produces a controlled and efficient AC output in the transformer by alternately switching the primary winding.