REVERSE CURRENT PREVENTING CIRCUIT FOR ELECTROMAGNETIC INTERFERENCE ATTENUATION COVER

摘要

PURPOSE: A reverse current preventing circuit is provided to prevent damages of system by preventing a reverse current, while protecting a human body from an electromagnetic interference. CONSTITUTION: A reverse current preventing circuit comprises an AC power input unit(310); a switching unit(330) for sensing and switching the active state and low state of the AC power; a rectifying and smoothing circuit unit(320) for receiving the AC power from the AC power input unit, and converting the AC power into a DC voltage by rectifying and smoothing the received AC power; a current limiting circuit unit(340) for receiving the DC voltage from the rectifying and smoothing circuit unit, using the received DC voltage as a driving power, receiving the AC power from the switching unit, limiting the reverse current by controlling the voltage through a comparator and a transistor, and turning on/off the switching unit in accordance with the on/off operation of the transistor; and an output unit(350) connected to the switching unit, wherein the output unit outputs the AC power in accordance with the operation of the current limiting circuit unit.