WIDE RANGE HORIZONTAL SIZE ADJUSTING CIRCUIT OF DISPLAY DEVICE

摘要

PURPOSE: A wide range horizontal size adjusting circuit is provided to maintain a horizontal size constantly by adjusting a current amount transferred to a pulse width modulating circuit. CONSTITUTION: A wide range horizontal size adjusting circuit comprises a horizontal output circuit(50) which outputs a tooth wave current to a deflection yoke. A voltage adjusting circuit(40) controls a voltage applied to the horizontal output circuit(40), and a micro computer(10) outputs a horizontal size adjustment signal in response to a synchronous signal. A synchronous processor(20) changes an output voltage according to the horizontal size adjustment signal provided through a data communication from the micro computer(10). A pulse width modulation circuit(30) adjusts a current amount flowing to the voltage adjusting circuit(40) according to an output voltage of the synchronous processor(20). A feed back circuit(60) feeds the output voltage of the voltage adjusting circuit(40) back to the pulse width modulation circuit(30). An addition voltage control part(100) adjusts a direct current voltage value provided to the pulse width modulation circuit(30) according to an output signal of the micro computer(10) which indicates a control signal differently according to a size of an input frequency.