| 摘要 |
This invention is an improved ranging system including an improved digital single shot circuit that has a resettable shift register therein so that a signal representative of the last target return occurring at any point of a predetermined range interval will be provided to the timing counter of the system. The digital single shot circuit includes a flip flop responsive to the first trigger pulse during the predetermined range interval, resetting the shift register so that, when the output pulse from the shift register representing the last target return is applied to the timing counter, it will terminate a fixed number of clock edges after the last trigger pulse determined by the number of stages of the shift register. The fixed delay in terminating the output of the shift register may represent the preset time of the readout counter. |
