| 摘要 |
942,250. Equalization; distributers. TELEFUNKEN PATENTVE-RWERTUNGSG.m.b.H. Dec. 8, 1961 [Jan. 10, 1961], No. 44022/61. Headings H4P and H4R. A chain of monostable flip-flops M 1 . . . M 10 is arranged to operate in the sequence M 1 . . . M 10 and then in the reverse sequence M 10 . .M 1 . As shown, when M 1 is operated it sets a bistable circuit B which enables a set of gates b<SP>I</SP>2. . . 10 whereby the trailing edge of the output each flip-flop such as M 1 triggers the succeeding flip-flop M 2 and so on. When M 10 is set, it sets the bi-stable circuit B to its other state so closing gates b<SP>I</SP>2 ... 10 and opening gates b<SP>II</SP>1 . . . 9 whereby the trailing edge of the M 10 output triggers M 9 and so on. The outputs of M 1 . . . .M 10 enable gates m 1 . . . m 10 to transmit a succession of pilot frequencies over the line L for the purpose of adjusting cosine equalizers at the distant end of the line. If a slight overlap of frequencies is required further flip-flop M<SP>1</SP> 1 . . .M<SP>1</SP> 10 may be provided, between M 1 . . . M 10 and gates m 1 . . . m 10 ,the further flip-flops having a slightly longer relaxation time. |
