HIGH VOLTAGE CIRCUIT OF A DISPLAY APPARATUS

摘要

PURPOSE: A high voltage circuit of a display apparatus is provided to stabilize a voltage generated from a secondary of a fly back transformer(FBT) by reducing a response time. CONSTITUTION: A high voltage circuit of a display apparatus comprises a feedback control part(100), a power supply driving element(Q12), a power supply part(200), an FBT driving element(Q11) and a resonance circuit part(300). In a case where an FBT normally outputs a direct current power, the feedback control part(100) receives one output voltage to generate a control signal of a different duty rate according to a variation of the received voltage. The power supply driving element(Q12) is switched according to the control signal from the feedback control part(100). In a case where the power supply driving element(Q12) is on, the power supply part(200) supplies current generated according to a variation of a secondary voltage to the primary so that a predetermined voltage is increased or decreased at the secondary. The FBT driving element(Q11) is switched according to an oscillation signal of the same frequency as a horizontal synchronous signal. The resonance circuit part(300) resonates so that the primary of the FBT is switched according to a switching of the drive element(Q11).