Sound’s Frequency can shift by moving of observer or sound source. This phenomenon
called Acoustic Doppler Effect. 

Controller

- Frequency
Count : Count changed 1Hz

- Display
range : 0~2Mhz

- Display
: LCD

- Frequency
changed Rob

Track

- Length
: 1.2 m Approx.

- Speed
adjusting

- Mount(1)

- Linear
bearing

Photogate Sensor built-in : Time, Speed
Display(LCD), Fixed Sensor Distance