An on board electrostatic filter for a vacuum cleaner is disclosed. The filter includes a pair of conductive filaments insulated from one another and located close together in a substantially parallel, side-by-side relationship. Circuitry is provided for applying an electrical potential difference between...http://www.google.es/patents/US5376168?utm_source=gb-gplus-sharePatente US5376168 - Electrostatic particle filtration
