| 摘要 |
PURPOSE:To prevent a maintenance operating circuit from oscillating by controlling two outputs regarding a maintenance operation signal so that one output of them is delayed. CONSTITUTION:Control signal C is obtained by operating flip-flop 3 via an adapter device and inverters 1 and 2 either by switching switch SW of a maintenance panel or with remote switch signal (RSW). Between flip-flop FFO of the adapter device and drivers 13 and 14, a delaying circuit consisting of counter 12, flip-flop circuits FF1 and FF2, and OR circuits OR1-OR3 is provided. When the output of FF0 is inverted through the operation of the maintenance panel or inversion of signal RSW, output (a) or (b) of driver 13 or 14 is delayed by the output of the delaying circuit, and consequently both inputs J and K of JKFF3 are never held at ''0'' or ''1'' at the same time, preventing oscillation. |
