| 摘要 |
PURPOSE:To detect a contact signal free from the effect of chattering, by having a simple processing constitution in which an exclusive OR is obtained for a contact signal which is fetched in a fixed cycle by means of an arithmetic circuit. CONSTITUTION:An arithmetic circuit 4 detects the contact signals S1-Sn supplied to input terminals 11-1n respectively. This circuit 4 fetches the contact signals with a fixed cycle and obtains an exclusive OR between the data fetched in the precedent time and the data fetched this time. Then an OR is obtained between the data having the exclusive OR and the data fetched this time. In addition, an exclusive OR is obtained between the data having said OR and the data having an OR of this time. In such a way, the contact signal is detected. |
