| 摘要 |
PURPOSE:To improve the operational efficiency of sweep, by using two pulse generators and up/down counters and by converting the output of the second counter to an analogue value and outputting it. CONSTITUTION:The output of the second pulse generator 21 is input to OR circuits 26 and 27 according to operations of switches 22 and 23 in the sweep direction by the logic of AND circuits 24 and 25, and up and down pulses 13 and 14 of automatic sweep are input to circuits 26 and 27 simultaneously. These pulses are input to the second up/down counter 18 till arrival at positive and negative-direction sweep limits, and a sweep voltage including automatic and manual sweep is output to output point 11 through D/A converter 8. In case of arrival at sweep limit 30 or 31, count pulses are broken by AND circuits 28 and 29, and in the course of manual sweep, the manual sweep set point is used as the sweep center at an automatic sweep stop time and an automatic sweep start time, and therefore, NOT circuit 19 and OR circuit 20 are operated to control the first up/down counter 7. As a result, the operational efficiency of sweep can be improved. |
