This is an oscillator circuit that will generate a frequency that you can hear and play it on the passive buzzer.
The Circuit
The capacitor (C1) and the resistor (R1) sets the frequency of the oscillation. Lower values means higher frequency.
Resistor (R2) sets the current for the transistor. And the transistor controls the current to the buzzer, turning it on and off rapidly.
Parts List
| Reference | Value |
|---|---|
| Battery | 9V |
| BZR1 | Passive Buzzer/Piezo Element |
| C1 | 100 nF |
| Q1 | BC547 |
| R1 | 10k |
| R2 | 10k |
| U1 | CD40106 |
The Layout
Here's an example of how you can build the circuit.
