AUTOMATED AC LINE FILTER AND SURGE SUPPRESSION APPARATUS AND METHOD

摘要

An automated AC line filter and surge suppression apparatus (100) having an inductive current sense loop (ICSL) circuit (10) for sensing inductive current at a load and controlling the application of AC line filter (112) to an AC power line to the load. Current sensor (12) in series with the input line senses inductive load current. A first bridge rectifier (14) rectifies the sensed load current to a proportionate DC voltage, which triggers a switch (24). The output of switch (24) is fed into an opto-isolator (26), which in turn controls second switch (28). Switch (28) connects or disconnects AC line filter (112) from the system according to a predetermined sensed inductive current at the load. MOVs (102) and capacitive elements (104) provide continuous surge suppression protection to the load. Selectable biasing (255) provides line filtering corresponding with a phase difference in inductive load current and a load voltage.