A display apparatus having a high voltage FBT driving circuit includes a
transformer having a primary and a secondary coil, a high voltage
detector to detect an output voltage of the secondary coil, a high
voltage compensator to output a high voltage compensating signal based on
the detected voltage, a DC voltage controller to adjust a DC voltage
according to the high voltage compensating signal and to output the
adjusted DC voltage to the primary coil, a horizontal deflector to
generate a horizontal deflecting pulse based on the DC voltage, a turns
ratio adjuster to adjust a turns ratio of the primary and secondary
coils, and a controller to control the turns ratio adjuster so as to make
the output DC voltage higher than a lower limit when the frequency of a
received horizontal synchronous signal is lower than a predetermined
reference level.