| 摘要 |
PURPOSE:To remove the noise of the chattering, etc., of an input signal and to decide the level of the input signal by equipping a latch means to continue to output a high (low) level signal when the output of a high (low) level timer means is changed to a high (low) level. CONSTITUTION:When a voltage between the Vcc terminal of an electronic control circuit 12 and a noise removing circuit 13 and the ground of a constant voltage source 10 goes to be low, the voltage of the both edges of a resistance R3 is lowered and a transistor TR2 is turned off. Then, the condition of an input terminal P1 is separated from an external circuit and it goes to be an open condition. At such a time, since an R terminal of an S-R flip-flop FF7 goes to be 'H', a T flip-flop FF6 is reset and the R terminal of the S-R flip-flop FF7 is caused to be 'L', a Q terminal of the S-R flip-flop FF7 goes to be 'H' and the voltage level of an output terminal P3 is fixed to be 'L'. Thus, the chattering of the input signal can be removed and malfunction to relate to the input of a switch is decreased in a place where the influence of an electric noise is large. |
