| 摘要 |
PURPOSE:To set hold off time in accordance with switching of sweep time, by connecting a constant-current power source to a rectifying element inserted between a capacitor and earth and comparing electric potential of this connected part with reference voltage. CONSTITUTION:When a trigger pulse T is inputted from an input part 10, a Tr9 is made into an opening state by a switch circuit 8 and a capacitor 2 is charged by a constant-current power source 25. This charged voltage is inputted into a comparator 7 through a buffer 26 and when it is reached a reference level, an output gate G3 is inverted because an input gate G1 of a logical operation circuit 6 becomes L and sweep is stopped by inverting the output of the circuit 8. On this occasion, the output of the comparator 7 is inverted, but the output of a comparator 5 is inverted to L and the gate G3 is the L as it is. Here, the output of a constant-current power source 4 is given to the capacitor 2 and Tr9 and voltage of a connection part 3 is raised until a diode 1 becomes to a conducted state. When this voltage is reached the reference value, the output of the comparator 5 is inverted and a trigger pulse holding state is made. |
