A tutorial on how to make a ticking sound generator circuit using 555 timer IC. The sound feels similar to the one used when showing a ticking time bomb in movies. A reverb container can be added over the speaker to make it sound similar to the tick tock audio emanated from mechanical clocks.
Watch the video above for detailed step by step instructions on how to build this circuit. Explanation of how the circuit works is also included in the video.
The timing between successive pair of beats can be changed to make it feel more like heartbeat sounds. (The speaker used in the video tutorial didn’t have enough bass to it. So only the timing feels similar to heart beat sounds)
Components Required
- 555 Timer IC
- 8 Ohm Speaker
- LED (Optional)
- Capacitors: 2 x 10uF
- Resistors: 47K, 220R
- Breadboard
- Few Breadboard Connectors
- (5-9)V Power Supply
Refer to the LED resistor table shown in the video tutorial for the exact value of LED’s series resistor (220R)
Circuit Diagram
How This Circuit Works
In this circuit, 555 timer IC is configured to work in astable / bistable mode. It means that voltage at the output of 555 IC continuously toggles between 0V and Vs (The supply voltage).
Each time there is a transition in the output voltage from 0V to Vs or from Vs to 0V, the diaphragm of the speaker moves rapidly. This movement generates a tick or tock sound depending on whether the diaphragm is moving up or down.
For more details on how this circuit works, visit this tutorial: Adjustable Flashing/Blinking LED Circuit using 555 Timer IC. It also contains visual animation of the circuit’s working.
Further Improvements
We can adjust the gap between successive beats, in real time, by replacing the Resistor R1 with a potentiometer. And multiple circuits with different beat/ticking frequencies can be combined to make audio synthesizer circuits.
Applications
- To add a mechanical feel to digital clocks
- In metronome circuits (They musicians to maintain rythm)
- In hypnotic devices that require flashing of lights and ticking sounds
If you have any queries/suggestions, feel free to post them in the comments section of this video: Tick Tock Sound Generator Circuit using 555 Timer IC