| 摘要 |
PURPOSE:To realize a fast periodical operation for five minutes or for six minutes by using a control signal to a logical gate which makes phase inversion at a fixed period. CONSTITUTION:The 1st propagation circuit 11, 2nd propagation circuit 12, and 3rd propagation circuit 13 are connected respectively in series which propagate inputs to outputs synchronizing with divided input signal VPHI. This scaler, constituted by logic gate 14 which is supplied ?with outputs of circuits 12 and 13, and control signal Vc and supplies its output to the input of circuit 11, makes alternatins between the five minute operation and six-minute operation by signal Vc. Here, the control signal which makes phase inversion at a fixed period is used as signal Vc, thereby making high-speed operation. In addition, this pre-scaler enables pre-scalers 10 and 11 to operate at a high speed by being supplied with the output of circuit 75 making two- minute periodical operation synchronizing to circuit 73 and the 2nd control signal V'c and by outputting the 1st control singal Vc. |
