摘要 |
An ionizer includes an alternating current (AC) voltage source having an output outputting a waveform with a positive half-cycle and a negative half-cycle, an electrode electrically coupled to the output of the AC voltage source, a reference proximate the electrode and a sensing circuit. The sensing circuit includes a return current nulling node electrically coupled to the output of the AC voltage source and the reference, a ground node separately electrically coupled to ground, a positive ion current sensor and a negative ion current sensor. The positive ion current sense node is configured to output a positive ion signal proportionate to a sensed positive ion current. The negative ion current sense node is configured to output a negative ion signal proportionate to a sensed negative ion current. |