Teaching tool, teaching material and teaching method to clarify the difference between electric current and voltage.

研制了一种新型电流表，它通过光斑的运动来显示被测电流，通过光斑的颜色来显示电压。由于这个工具可以让学生感觉好像他们正在观察电的视觉图像，所以很容易准备与学生观察相匹配的电路示意图解释。从这个角度出发，我们在初中生的试课中使用了一个餐厅模型和这个电流表，发现这种结合比用普通的流体流动模型解释更有效地让学生认识到电流和电压的区别。为了教育目的，还研究了使用夹紧式电流表的可能性。明确了钳式电流表可以在小学和初中的科学课上使用，并且可以帮助学生学习电流和电压的区别。

A new type of ammeter was developed which indicates the measured current by the movement of a spot of light and the voltage by the color of the spot. Since this tool can make students feel as if they are observing a visual image of electricity, it is easy to prepare schematic explanations on electric circuits that match the students' observations. From such a viewpoint we used a restaurant model with this ammeter in a trial lesson for junior high school students, and found that such a combination is more effective to make them recognize the difference between current and voltage than explanations using ordinary fluid-flow models.The possibility of using clamp-on ammeters was also investigated for educational purposes. It was made clear that clamp-on ammeters can be used in science classes in elementary school as well as in junior high school, and that they may help students to learn the difference between current and voltage.