在高中物理教学中,电磁打点计时器作为计时工具,广泛应用在学生的实验中,如研究物体作匀变速运动规律,验证牛顿第二定律,验证机械能守恒定律等实验。是学生实验的重要仪器之一。但从使用情况看来,还存在着不少缺点,如有打点不够稳定、时而出现打双点、时而打点不清或丢点的现象;此外仪器没有固定支架,学生操作使用时容易移动位置、甚至落地摔坏。我们在教学实践中,感到有必要加以适当改进。为此,我们在原来打点计时器的基本结构的基础上,重新设计制作了一种电磁打点计时器,如图1所示,经多次实验操作,效果很好。 In the high school physics teaching, the electromagnetism hits the timer as the time counting tool, widely uses in the student’s experiment, like studies the law that the object carries on the uniform variable speed movement, the verification Newton second law, verifies the mechanical energy conservation law and so on the experiment. It is one of the important instruments for student experiments. However, from the perspective of usage, there are still many shortcomings, such as the lack of stability in the playing point, the occurrence of double-pointing, sometimes unclear or missing points; in addition, the instrument does not have a fixed bracket, and the student can easily move the position during operation. Even crashed. We feel it necessary to make appropriate improvements in our teaching practice. To this end, based on the basic structure of the original timer, we have redesigned and created an electromagnetic dotting timer. As shown in Figure 1, after many experiments, the results are very good.