摘要
根据多普勒效应基本原理,利用超声波作为信号源制作了多普勒效应演示仪。利用40 kHz超声波作为信号源,具有频率高、方向性好、发射功率高、不易受干扰等优点,能够在有限的教室空间里实现多普勒效应演示。理论证明,速度为340 m/s的超声波,当物体的运动速度在1～2 m/s变化时,差频的变化范围约为120～240 Hz,人耳就能很容易感受到多普勒效应。同时,该仪器还具有制作简单、易携带的优点,并自带测距、测速等附加功能。
This paper is focused on the design of a circuit which can emit ultrasonic waves to demonstrate Doppler effect. With high frequency, good direction, high transmission power, and non-disturbance, the circuit which can demonstrate Doppler effect within limited space is easily made with low cost, has the appending function of fine ranging etc. It is proved that the change of frequency is approximately 120 Hz to 240 Hz when the speed of ultrasonic wave is 340 m/s and the speed of moving objects is in the range of 1 m/s to 2 m/s. Therefore, the human ears can easily feel the Doppler effect.
出处
《实验室研究与探索》
CAS
北大核心
2012年第10期44-45,共2页
Research and Exploration In Laboratory
基金
江苏省高等教育教改研究课题(2011JSJG147)
江苏技术师范学院综合设计性试验项目(2S10017)
关键词
多普勒效应
超声波
演示仪
Doppler effect
ultrasonic wave
demonstrator
