HORIZONTAL OSCILLATION FREQUENCY LIMIT CIRCUIT

摘要

PURPOSE:To set dispersion in an oscillation frequency limit operating point at mass-production to a narrow range by changing the setting of the resistor. CONSTITUTION:An output of an f-v conversion circuit 5 is given to a noninverting input terminal of a voltage comparator 1 and a slider of a variable resistor 2 is connected to an inverting input terminal. Both terminals of the resistor 2 are connected to a DC power supply and a GND. A diode 4 for connection open switching and the resistor 3 for horizontal oscillation circuit changeover are connected to an output terminal of the comparator 1. An f-v voltage is inputted to the noninverting input terminal of the comparator 1 and a voltage from the resistor 2 is inputted to the inverting input terminal to obtain a reference voltage. The f-v voltage and a reference voltage are compared and when an input signal horizontal frequency is low, the resistor 3 connecting to the output terminal of the comparator 1 is connected to a horizontal oscillation frequency control section to shift the oscillating frequency of the horizontal oscillation circuit. The dispersion in the oscillating frequency limit operating point at mass-production is set within a narrow range by changing the setting of the resistor 2.