Doppler Effect Kit STEM Lab
Product Code : SCL-ES-12499
Quick Answer: The Doppler Effect Kit STEM Lab swings a 9V piezo buzzer, tuned to 4.0 kHz, on a 45 cm motor-driven arm so that students hear its pitch rise as it approaches and fall as it moves away. A built-in 4-digit LED frequency counter displays the frequency.
Last updated: October 2026
Key Features
- 9V piezo buzzer with a 4.0 kHz tone as the moving sound source
- 45 cm sweep arm driven by a 12V DC motor with multi-step speed control
- Built-in 4-digit LED frequency counter
- 3.5mm sensor taps for connecting an oscilloscope
- Heavy cast iron base with vibration-absorbing rubber feet
- 12V DC power adapter included; 9V battery snap for the buzzer
Technical Specifications
| Specification | Value |
|---|---|
| Sound source | 9V piezo buzzer, 4.0 kHz |
| Drive | 12V DC motor, multi-step variable speed |
| Sweep arm radius | 45 cm |
| Display | 4-digit LED frequency counter |
| Outputs | 3.5mm oscilloscope sensor taps |
| Base | Cast iron with rubber feet |
| Power | 12V DC adapter (included), 9V battery snap |
About This Product
As the arm sweeps the buzzer towards a listener or microphone the waves in front of it bunch up and the note sounds higher; as it passes and moves away they spread out and the note drops. Changing the motor speed shows that a faster source gives a bigger shift, and the counter and oscilloscope taps let students measure the change instead of only hearing it, with links to radar speed checks and red and blue shift in astronomy.
Frequently Asked Questions
What frequency does the buzzer in the Doppler Effect Kit STEM Lab produce?
The 9V piezo buzzer gives a steady 4.0 kHz tone, and the apparent frequency changes as the 45 cm arm carries it towards and away from the listener.
Related: Electrostatics & Sound, Organ Pipe Model STEM Lab and Sound Pipes Model STEM Lab.
For a quotation on the Doppler Effect Kit STEM Lab, contact Educational Instrument.
