| 摘要 |
PURPOSE:To make screen display of the same size possible even when deflection frequencies are different, by outputting a saw-tooth wave, generated by two time constant circuit, with a discrimination according to the kind of trigger pulses. CONSTITUTION:Vertical deflecting circuit 5 is provided with time constant circuits consisting of variable resistors 53 and 54 differing in time constant and active elements 56 and 57, and a saw-tooth wave of the same amplitude is output to output transistor 51 by charging and discharging capacitor 52. Pulse forming circuit 4 forms and outputs trigger pulses corresponding to the 1st and 2nd synchronizing signals. Then, discriminating circuit 6 outputs it by the trigger signal of circuit 4 and holding circuit 7 holds it. Thus, when the 1st synchronizing signal is input, element 56 is put into operation and element 57 out of operation; when the 2nd synchronizing signal is input, element 56 is OFF and element 57 is ON, thereby outputting the saw-tooth wave, based upon the time constant to terminal 55. |
