Abstract: A method and apparatus for generating a supply of pulsed power to an electrostatic precipitator where a residual collection field is maintained on the electrodes during interpulse periods while, in addition, high voltage pulses in excess of the residual are periodically impressed on the electrodes. The apparatus includes a series tuned circuit having a pulse forming section which creates a single damped cycle of oscillation to produce ionization current from a corona discharge electrode before unused power is returned to the pulse forming section. A blocking diode prevents the voltage on the precipitator from falling below the corona threshold voltage, and a series tuned trap circuit maintains the diode in conduction during pulsing to allow the return of unused energy.