Electronic air filtering apparatus

• Main Authors: RYLICKI; EDWARD J, MASON; EDWIN E, FATHAUER; GEORGE H, FOWLER, JR.; JAMES M
• Format: Patent
• Language: English
• Published: 18.06.1985
• Edition: 3
• Subjects: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC,OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWERSUPPLY SYSTEMS; CONTROL OR REGULATION THEREOF; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLIDMATERIALS OR FLUIDS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROMSOLID MATERIALS OR FLUIDS; PERFORMING OPERATIONS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS; SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATICTABLES OR JIGS; TRANSPORTING

Air filtering apparatus includes a filter cell having ionizing and collecting structure, a high voltage power supply and control unit for supplying a high voltage to the filter cell, a separate low voltage power supply unit for supplying operating power to the high voltage power supply unit and a separate probe unit for monitoring the flow of air within a duct in which the filter cell is installed. The high voltage power supply and control unit includes an output transistor in series with a primary winding of a step-up transformer and controlled by an oscillator circuit which is operative to control and limit the output voltage and current and also the current through the output transistor. The probe unit includes a pair of thermistors and a bridge circuit and operates to provide a signal which is independent of variables other than air flow velocity. A modified apparatus is also disclosed, arranged for portable use and arranged for energization from a standard power line with no separate low voltage supply.