June 17, 2026
Your wake-up call goes boom
Show HN: Capacitor Alarm Clock
This DIY clock wakes you up with a literal explosion and the comments are losing it
TLDR: A hobbyist built an alarm clock that wakes people by making an electronic part explode, and even the creator says it’s more joke than practical gadget. Commenters were split between calling it dangerous insanity, weirdly beautiful art, and an elite setup for jokes about toxic breakfast smells and time-travel puns.
File this under things the internet absolutely should not encourage but definitely will: a maker posted a DIY alarm clock that wakes you up by blowing a capacitor — basically a small electronic part — with a loud pop. The creator openly admits it’s a high-effort joke, warns that the blast is violent and the fumes are nasty, and still lovingly packed it with bells and whistles like Wi‑Fi setup, a tiny screen, a web page for settings, and even three separate slots so your mornings can apparently come with a choice of explosions. Yes, really. You can see the demo on the project’s GitHub page.
The community reaction? A perfect mix of horror, admiration, and chaos. One commenter summed up the general mood with the deeply online seal of approval: “Based. Unhinged.” Another went full dark comedy, joking about the “smell of vaporized electrolyte” as a wake-up scent, which is about as close as this thread gets to a wellness review. The strongest opinion wasn’t really “is this useful?” — everyone seems to agree it’s wildly impractical — but whether it crosses the line from dangerous nonsense into performance art. One commenter literally called it art, saying it captures the wastefulness of modern gadgets in one dramatic bang. Meanwhile, others were just trying to help the rubberneckers find the demo video, because of course the crowd wanted receipts. And then came the inevitable pun lobby: “How about a flux capacitor clock?” The internet saw a ridiculous exploding alarm and responded in the only way it knows how: with memes, concern, and applause.
Key Points
- •The project is an ESP32-based alarm clock that uses capacitor discharge as its alarm mechanism and is presented with strong safety warnings.
- •It includes a 128x64 SSD1315 display, three capacitor slots, automatic time sync via NTP, and local plus web-based configuration.
- •The hardware supports up to 3A through capacitors, uses 10 ohm current-limiting resistors, and accepts power from USB-C or a 12–15V barrel jack.
- •The article provides access to PCB files, CAD files, a bill of materials, and firmware build instructions using PlatformIO and VSCode.
- •The author notes thermal limitations of the voltage regulators, suggests a buck converter as an alternative, and gives capacitor sourcing guidance including avoiding top pressure-release slots and aiming for about 16V ratings.