在半自动、全自动磨床上,砂轮的修整往往参予循环。在预选磨削件数达到预选数,亦即记数器达到预选数字时,磨床自行开始修整砂轮。开始修整以后或修整完毕,记数器清零。若是全自动磨床,修整完毕自行转入磨削工件,并重新记数。以往我们经常是采用JJDM型记数器,但多年来使用结果证明,这种电磁机械式预选记数器性能不够稳定,并容易损坏。这里介绍一种由集成元件构成的电子预选记数器,由于磨床上记数通常是在两位数以内,所以这里仅就两位数将原理介绍如下。本线路包括记数显示部分(图1)和比较输出部分(图2)两大部分。所有集成元件用5伏直流电源供电,输出继电器用18 In semi-automatic, fully automatic grinding machines, wheel dressing often participate in the cycle. When the number of preselected grinding reaches the preselected number, that is, when the register reaches the preselected number, the grinder starts to trim the grinding wheel itself. After finishing trimming or trimming is completed, the counter is cleared. If the automatic grinding machine, finishing their own grinding into the workpiece, and re-count. In the past we often used the JJDM type register, but the results of many years of use proved that the electromechanical preselected register performance is not stable enough and easily damaged. Here is a description of an electronic preselected register made up of integrated components. Since the count on the grinding machine is usually within two digits, here the principle is described in terms of two digits only. The line includes a count display part (Figure 1) and comparison output part (Figure 2) two parts. All integrated components with 5V DC power supply, the output relay with 18