High-voltage stabilization circuit of monitor

摘要

The present invention relates to a high-voltage stabilization circuit for a monitor. The circuit of the present invention turns on / off a switching element (FET) by a PWM control signal and supplies the power supply voltage Vcc input from the switching power supply circuit SMPS to a scan B + To-DC converter (2) for outputting the converted signal; The AC high voltage induced on the secondary side by the scan B + voltage applied to the primary side of the flyback transformer (FBT) is referred to as a DC high voltage ($V$_H(R11) connected in series between the switching power supply circuit (SMPS) and the DC / DC converter (2), and a high voltage circuit (3) , R12); A switching transistor Q11 connected in parallel to the power supply voltage drop resistors R11 and R12; And a switching transistor (Q11) for switching off the switching transistor (Q11) when the pulse voltage is equal to or higher than a predetermined voltage by detecting a pulse voltage output from the flyback transformer (FBT) DC converter 2 from the switching power supply circuit SMPS when the voltage detected by the high voltage circuit 3 is equal to or higher than the rated voltage and the power supply voltage Vcc ), Thereby lowering the scan B + voltage and outputting the high voltage ($V$_H).