Capacitor Alarm Clock
Details
- External ID
- 48526174
- Source
- HN
- Company
- —
- Product
- Capacitor Alarm Clock
- Website domain
- github.com
- Launched
- June 14, 2026
- Cohort
- —
- Upvotes
- 153
- Upvotes percentile
- 0.9412568306010929
- Tags
- —
- Fetched at
- Sept. 7, 2026, 9:26 p.m.
- Updated at
- Sept. 7, 2026, 9:26 p.m.
Description
I made an alarm clock that blows up capacitors to wake you up.There are more details on the Github repo but it's made from an esp32-c3 as the microcontroller, with 3 capacitor slots. There are relays on each capacitor slot to put 15v reverse voltage on the capacitor, with 5.1 ohm resistors on each slot for current limiting in case the capacitor shorts out. I also chucked in an SSD1315 OLED to show the time and a menu to configure it, although there's a web UI as well. The esp32 also means you can fetch the time from NTP.It also functions as a small heater since I used LDOs to step down 15v to 3.3v for the esp32, I was lazy and didn't use a buck converter circuit :)
Enrichment
- Theme
- sleep, wake, and clock utilities
- Vertical
- —
- Function
- Hardware & robotics
- Audience
- B2C
- AI stance
- Not AI
- Project type
- Hobby / open-source project
- Normalized one-liner
- capacitor-based alarm clock
- Manually corrected
- False
Could you build this?
No This is a physical hardware project involving an ESP32 microcontroller, custom relay circuits, and high-voltage electronics to physically explode components.
What it would actually take: The system requires custom PCB design, an ESP32-C3 microcontroller, mechanical enclosures, and power switching circuitry (relays, power resistors, and a 15V reverse voltage supply). The primary hurdles are physical electronics layout, electrical safety isolation, and C++/MicroPython firmware development to control the relays on alarm triggers. Building it requires electrical engineering skills, soldering, and embedded hardware development.
Discussion
20 comments analyzed.
Concerns raised: Safety hazard - eye/hearing protection required for capacitor discharge, Unreliable timing - capacitors don't go off reliably below 12V, USB power limitation - pulls ~1A, hits 3A USB limit, Low-quality capacitors may not perform as expected
Feature requests: Capacitor-based alarm clock timer using charge/discharge delay methods, Higher voltage photoflash driver circuit for more potent discharge
Competitors
Other products that read as similar to this one — 105 launches clear the similarity bar, closest 8 shown.
Attention rank: #7 of 106 (itself plus its competitors, highest first — normalized so YC and Product Hunt are compared fairly).
Launched 212 days after the earliest competitor.
- reclaim-spotify-clock · github · 2026-09-25 · 11 upvotes · similarity 0.50
- WakeUp: Alarm Clock & Goals · ph · 2026-09-12 · 2 upvotes · similarity 0.49
- UltraAlarm: Get Up Alarm Clock App · ph · 2026-09-12 · 1 upvotes · similarity 0.48
- Run Late — GPS alarm clock · ph · 2026-09-23 · 1 upvotes · similarity 0.47
- alarm_v3 · github · 2026-09-19 · 9 upvotes · similarity 0.46
- Owlish · ph · 2026-09-22 · 2 upvotes · similarity 0.46
- Lazy Alarm — Wake Up Your Brain · ph · 2026-09-29 · 1 upvotes · similarity 0.46
- Nenne · ph · 2026-09-25 · 2 upvotes · similarity 0.46
Other launches for this product
- No other launches for this product.