| 摘要 |
PURPOSE:To reduce the variation of the horizontal amplitude for the TV set, by adding the voltage generated across the resistance for protecting rectified current to the reference voltage and then lowering the output voltage in a certain proportion to the increase of the current of the power supply unit which is caused by the increment of the beam current or other factors. CONSTITUTION:One end of the dash preventing resistor R1 connected to the output side of the rectifier D1 is connected in series to the Zener diode D2 for reference voltage of the transistor TR2 for detection of the difference. And the voltage generated across the resistor R1 is added to the reference voltage. And when the current flowing to the power supply unit is increased due to the increment of the beam current of the TV set, the voltage generated across the resistor R1 increases with a reduction secured for the emitter voltage of the TR2. Thus the collector current is increased. Then the base voltage of the TR1 is lowered down, and then the voltage to be supplied to the TV set is reduced in a certain proportion to the increase of the current. Thus the variation can be reduced for the horizontal amplitude. |
