Component guide
How to Use a Buzzer
- Grades 3-8
- 10 minute activity
- NGSS 4-PS3-2
Quick answer
A buzzer turns electricity into sound. To use one in a play dough circuit, push its red wire into the dough connected to the battery holder's red wire and its black wire into the dough connected to the black wire. Buzzers have polarity, so red goes to red and black goes to black.
Try it with dough
Make your dough buzz
You need
- Battery holder with 4 AA batteries
- Conductive (salty) play dough
- 1 buzzer
Steps
- Make two pieces of conductive dough and set them a finger-width apart.
- Push the red battery wire into one piece and the black wire into the other.
- Push the buzzer's red wire into the piece with the red battery wire.
- Push the buzzer's black wire into the piece with the black battery wire.
- Switch the battery holder on and listen.
What happens
The buzzer sounds. Electricity flows from the battery holder through the dough and through the buzzer, which turns it into vibration and sound.
Not working?
- Check that red goes to red and black goes to black.
- Make sure the two pieces of dough are not touching.
- Push the wires deeper into the dough.
- Try fresh batteries.
How a mechanical buzzer works
Inside a mechanical buzzer is a coil of wire. When electricity flows through the coil, it becomes an electromagnet and pulls a thin metal tab called the armature toward it.
That movement breaks the connection, so the magnet switches off and the tab springs back, which reconnects the circuit and starts it all over again. This happens hundreds of times every second, and the fast vibration makes a low, raspy buzz.
How a piezo buzzer works
A piezo buzzer has a thin disc made of a special piezoelectric material. When electricity reaches it, the disc bends. A tiny circuit inside switches the electricity on and off thousands of times a second, so the disc flexes back and forth and pushes the air to make a high, clear beep.
Piezo materials work backwards too. Squeeze or tap one and it makes a little electricity. That is how the click igniter on a gas grill makes its spark.
Mechanical vs. piezo buzzer
Mechanical buzzer
- Sound: a low, raspy buzz
- How: an electromagnet pulls a metal tab
- Found in: doorbells, alarm clocks and game show buzzers
Piezo buzzer
- Sound: a high, clear beep
- How: a piezoelectric disc flexes
- Found in: smoke alarms, microwaves, watches and toys
Buzzer tips and ideas
- Keep the sound hole uncovered by dough so the sound can get out.
- Too loud? Put a small piece of tape over the hole.
- Add a switch so you control when it sounds.
- Put a buzzer and an LED across the same gap and you get light and sound together, like an alarm.
Key words
- Buzzer
- A part that turns electricity into sound.
- Electromagnet
- A coil of wire that becomes a magnet when electricity flows through it.
- Armature
- The metal tab an electromagnet pulls on in a mechanical buzzer.
- Piezoelectric
- A material that bends when electricity reaches it, and makes electricity when it is squeezed.
- Vibration
- A fast back-and-forth movement. Vibrations make sound.
- Polarity
- Having a positive and a negative side. Buzzers have polarity.
Watch: how to use a buzzer
Buzzer questions
How do you wire a buzzer?
Connect the buzzer's red wire to the positive (red) side of the circuit and its black wire to the negative (black) side. In a play dough circuit, that means red wire into the dough with the red battery wire and black wire into the dough with the black battery wire.
Does a buzzer have polarity?
Yes. A buzzer only works when its red wire is on the positive side and its black wire is on the negative side.
What is a piezo buzzer?
A piezo buzzer makes sound with a thin piezoelectric disc that bends back and forth when electricity reaches it. It makes a high, clear beep and is used in smoke alarms, microwaves and watches.
What is the difference between a piezo buzzer and a mechanical buzzer?
A mechanical buzzer uses an electromagnet to pull a metal tab back and forth and makes a low buzz. A piezo buzzer uses a flexing crystal disc and makes a higher beep.
Why is my buzzer not making a sound?
Check that red goes to the red side and black goes to the black side, the two pieces of dough are not touching, the wires are pushed in deeply and the batteries are fresh.
Can I use a buzzer and an LED together?
Yes. Put both across the same gap, each with its positive side toward the red wire, and you get light and sound at the same time.
Printable guide: Components Explained (PDF)
Next, try a project
Build the Buzzing Bee A free step-by-step project with printable instructions.