| 摘要 |
PURPOSE: A shutdown prevention circuit for an inverter is provided to prevent a cold CRT controller from being maintained at the shutdown state during a temporary power outage. CONSTITUTION: An inverter comprises an on/off control circuit(11) for transmitting and cutting off an input voltage of a predetermined level in accordance with the on/off control signal input from an external source; a constant voltage circuit(12) for converting the input voltage transmitted through the on/off control circuit into a constant voltage of a lever lower than the predetermined level, and outputting the converted voltage; a cold CRT controller(13) for outputting a driving signal of a pulse type and controlling a luminance in accordance with the dimming voltage output from an external source and a feedback voltage; a switching circuit(14) for converting the DC input voltage input from an external source into an AC voltage, and outputting the converted AC power; a transformer(15) for boosting the AC power output from the switching circuit, and outputting a high voltage; a cold CRT(16) which is turned on by the high voltage output from the transformer; a feedback circuit(17) for converting the current flowing through the cold CRT into a voltage, and outputting the voltage to the cold CRT controller; a dimming circuit(18) for generating a dimming voltage, and outputting the dimming voltage to the cold CRT controller; and a shutdown prevention circuit(100) including voltage divider resistors(R1,R2) for dividing input voltages, and a reset circuit(110) for resetting the cold CRT controller by generating an output voltage of a ground level when the voltage divided by the voltage divider resistor has a size lower than a predetermined level and outputting the voltage to the cold CRT controller.
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