A 555-timer PCB that drives voice coils — turning any surface into a speaker. Designed for workshop accessibility with immediate, tactile audio feedback for beginners who've never soldered before.
The Idea
This project emerged from a desire to create an accessible entry point into electronics education, drawing inspiration from the iconic Atari system's simple yet effective sound generation circuits. By combining the classic 555 timer IC with modern voice coil technology, we developed a PCB that teaches fundamental electronics principles while demonstrating how any surface can become a resonant speaker.
Voice Coils
Rather than traditional speakers, this design uses voice coils that attach to various surfaces — wood, metal, plastic, or even glass — transforming them into resonant sound producers. This creates unique acoustic properties and provides a tangible demonstration of how electromagnetic principles work in audio reproduction. Press the coil to a table, a door, a window — each surface sounds different.
Workshop Design
Large, clearly labelled components make soldering accessible to beginners. The circuit's simplicity ensures participants can complete the build within a typical two-hour workshop. The immediate audio feedback — the board makes sound the moment it's powered — reinforces the connection between theory and result.
Specifications
- Core IC: 555 timer in astable configuration
- Output: variable frequency square wave, adjustable via potentiometer
- Power: 9V battery or DC supply
- Voice coil compatibility: standard 4–8 ohm coils
- PCB size: optimised for workshop handling
Assembled PCB showing 555 timer, potentiometer, and voice coil connector — clean overhead shot
Workshop participant soldering the board for the first time — hands, soldering iron, focused expression
Voice coil pressed against a wooden table surface, wires trailing to PCB — testing moment