---
id: task-1
title: Build Unpowered Crystal Telephone
status: To Do
assignee: []
created_date: '2026-01-05 23:02'
labels:
  - hardware
  - piezoelectric
dependencies: []
priority: high
---

## Description

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Build the zero-power piezoelectric crystal telephone that demonstrates the reversibility of the piezoelectric effect. Two crystals connected by wire - no batteries needed\!

This project demonstrates:
- Direct piezoelectric effect (sound → electricity)
- Inverse piezoelectric effect (electricity → sound)
- Energy flows both directions through the same crystal

Refer to piezoelectric-circuits-guide.md for full instructions.
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## Acceptance Criteria
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- [ ] #1 Acquire 2x piezo discs (27mm or 35mm)
- [ ] #2 Build acoustic couplers (funnels or cups)
- [ ] #3 Solder wires between the two piezos
- [ ] #4 Test communication at 1-3 meters
- [ ] #5 Test maximum distance achievable
- [ ] #6 Document results with photos/video
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