| 摘要 |
1,156,590. Time base generator. INTERNATIONAL STANDARD ELECTRIC CORP. 7 Dec., 1967 [13 Dec., 1966], No. 55751/67. Heading G4A. An electrical time base generator comprises a delay line with a plurality of taps to which are connected threshold detectors for opening and closing gating means, one of which means is provided for each impulse to be generated. As shown (Fig. 1), a delay line LR comprising inductances sf and capacitors cd has a number of taps pr to which differential amplifiers AD may be selectively connected. Each differential amplifier is such as to conduct when its side input terminal is negative with respect to its other input terminal. Thus, when the leading edge of the pulse travelling down the line LR reaches the tap connected to AD3, AND-gate pt5 is opened to initiate the impulse td. The gate pt5 is closed to terminate the impulse td when the leading edge of the travelling pulse reaches the tap connected to AD4. The cycle of operations is started by a pulse sd applied to gate pt2. The first two differential amplifiers AD1 and AD2 and gates pt1 and pt2 are concerned with accurately timing the length of the travelling pulse and with providing impulses to and th for setting control bi-stable devices aa and ab respectively. A further AND-gate pt3 at the input to the delay line enables the travelling pulse to be regenerated for a second cycle to be performed. Impulses of relatively long duration may be produced by using impulses generated using the delay line to set and reset bi-stable devices such as tl1 and ti1. Impulses may be generated selectively in either the first cycle only, the second cycle only or both. |
