| 摘要 |
PURPOSE:To enable to keep the screen size displayed on the tube surface of a cathode ray tube constant, by generating a saw tooth wave corresponding to the period of an inputted vertical synchronizing signal. CONSTITUTION:A vertical synchronizing signal is inputted to the base of a transistor (TR) 8. A DC voltage proportional to the period of the vertical synchronizing signal is produced at the collector of the TR8 with an integration circuit consisting of the TR8 of switching operation, resistor 9 and capacitor 10, and a saw tooth control voltage corresponding to the DC voltage is generated to the output of a peak hold circuit consisting of a capacitor 22, diode 21 and buffer amplifier 11. A collector current corresponding to a saw tooth control voltage flows to the collector of a TR16, and a current inversely corresponding to the saw tooth control voltage flows to a capacitor 18. The slope of the saw tooth voltage changes corresponding to the period of the vertical synchronizing signal and the peak voltage can be made constant with a TR23. |
