OVERVOLTAGE PROTECTION CIRCUIT

摘要

PURPOSE: An overvoltage protection circuit is provided to prevent a damage of device due to an overvoltage by detecting and controlling an input voltage more than a standard voltage level. CONSTITUTION: An overvoltage protection circuit comprises a polarity determination portion(11), a first static voltage circuit(12), a micro computer(13), a key input portion(14) and a second static voltage circuit(15). The overvoltage protection circuit further comprises a level detection portion and a control portion. The level detection portion controls an operation of the first static voltage circuit by checking a voltage level of a direct current electric power. The control portion controls an operation of the second static voltage circuit according to the control of the microcomputer and the level detection portion.