SIGMOID COMPENSATING CAPACITOR SWITCHING DEVICE FOR DISPLAY MONITORING DEVICE

摘要

PURPOSE: To prevent deterioration of a switch element by controlling continuity/ discontinuity of the switch element according to a horizontal frequency and connecting and controlling a sigmoid compensating capacitor fit a frequency of a horizontal synchronous signal with a deflection coil. ;CONSTITUTION: A sigmoid compensating capacitor device 15 provides and output switch control signals S1, S2 for allowing continuity to switch elements Q2, Q3 and a power source ON output signal is provided an output to a power source circuit 16 when it receives a source ON request signal. Then, a frequency of the horizontal synchronous signal is detected by a detecting means 12 and a table is referred to based on the detected signal and a horizontal frequency data and the signals S1, S2 are read out and the horizontal frequency data is provided an output to a horizontal oscillation circuit 17 and a frequency of a horizontal deflection circuit 1 is determined. The circuit 1 waits for designated time required for the frequency to be stabilized and outputs a switch signal read out from the table to the elements Q2, Q3 and switches the elements Q2 and Q3. Thereby, voltage is not applied excessively to the elements Q2 and Q3 and deterioration of the switch elements at power source ON can be prevented.;COPYRIGHT: (C)1995,JPO