| 摘要 |
PURPOSE:To avoid a faulty operation of a cylinder motor, by detecting the missing of a horizontal synchronizing signal, and then using this detected output to gate the sampling pulse. CONSTITUTION:When a decoded synchronizing signal (a) has a missing, the ''L'' level period is increased for an output signal (b) of a monostable-multivibrator 1. A monostable-multivibrator 9 is triggered at the fall edge of the signal (b), and the fall edge of a produced signal (g) is set so that the signal (b) may kept at an ''H'' level in the normal state. However, the output Q of a D-FF7 is inverted to an ''L'' level since the signal (b) attains an ''L'' level. As a result, an AND gate 8 closes to produce no sampling signal (j). As a result, the previous sampling voltage is held even through the signal (a) is missed due to the noise. |
