| 摘要 |
PURPOSE:To prevent malfunction due to chattering and noise, by avoiding read-in in a storage circuit when a switch input is absent for a fixed time or more. CONSTITUTION:When a switch 1 is closed, a switch signal read-in signal 20 is at ''0'' and it is read in the 1st storage circuit 15, an output 21 is at ''1'', the output is fetched to the 2nd storage circuit 16 at the timing of the next signal 20, the output is differentiated at a latch 17 and a gate 18 for the output at the point 19. The switch input is read in by the storage circuit 15 only when the signal 20 is at ''0'', and tge signal 20 is at ''0'' immediately when the switch 1 is opened. Thus, taking the period of 20 as 31.25msec and that of ''0'' of 20 as 1.95msec, no differentiating signal of the switch is outputted if the switch input has the period of ''1'' for more than 29.3msec. On the other hand, since chattering and noise due to switching do not 1ast in 29.3msec or more, no input is received other than the switch operation. |
