| 摘要 |
PURPOSE:To obtain a switching pulse generating circuit being convenient practically by providing counters and decoders corresponding to the number of changeover circuits to allow them to correspond to the sequential feed transmitting one by one pulse and the direct changeover transmitting an optional number of pulses. CONSTITUTION:A television signal is switched and outputted by an output ''0'' of a decoder IC7 at application of power, and when a switching pulse is inputted, the decoder IC7 is shifted via a counter IC6 and the selective switching of the input signal is attained sequentially as a video input 1 by a decoder output ''1'' and as a video input 2 by a decoder output ''2''. In regard to input pulses from the direct mode, pulses of number differ according to the mode as one pulse at the mode ''0'' (television) and two pulses at the mode ''1'' (video input 1)... are inputted. Through the constitution above, the changeover circuit used for both the sequential changeover and the direct changeover is obtained. |
