| 摘要 |
PURPOSE:To automatically stop sweeping operation at a set point and to prevent the operation from being interrupted by providing a comparing circuit which compares the output of an integrator with the set point, and then applying the output of the comparing circuit to a flip-flop for controlling the integrating operation. CONSTITUTION:A DC voltage -E is integrated through an operational amplifier 1, a capacitor 2, and a resistance 3. The output voltage V0 of the operational amplifier 1 is compared with a set voltage VF by a comparing circuit 54, whose output is applied to the clock terminal CK of a D type FF51. The input terminal D of the D type FF51 is grounded and a switch 56 for stopping the integration is controlled by the output Q. When a switch 52 is closed while the comparing circuit 54 generates an output L, the D type FF51 is set through an OR circuit 57 and the switch 56 is closed by the output Q to start the integration. When the output voltage V0 reaches the set voltage VF, the D type FF51 reads a D input L and the switch 56 is turned off to stop the integration. Then, a switch 53 is closed to reset the D type FF51, stopping the integration at an optional point of time. |
