Future Gadget #5: Kerberos Tap#
| Designation | Future Gadget #5 |
| Common name | Kerberos Tap |
| Function | Voice-commanded three-way power strip |
| Inventors | Daru (electronics), Okabe (mythology) |
| Channels | 3 relays × 1500 W |
| Wake word | "Kerberos!" (non-negotiable) |
| Recognition accuracy | 71% (lab ambient), 12% (Comima ambient) |
| Vocabulary | 9 commands |
| Response latency | 0.8 s plus dramatic pause |
| Status | In service, main bench |
Future Gadget #5, the Kerberos Tap, is a voice-controlled power strip: three switched outlets, one salvaged speech-recognition module, and a name that recasts flipping a relay as commanding the hound of Hades. Shout "Kerberos! First head, wake!" and the PhoneWave's bench light comes on. Shout it again slightly differently and, 29% of the time, nothing happens, which the lab has agreed to call "the hound's discretion."
The Tap exists because the lab's main bench accumulated three devices whose plugs live behind the IBN 5100 — a machine that weighs 25 kg and does not move for anyone's convenience. After the third bench-diving expedition in one week, Daru wired three relays to a discontinued voice-recognition doorbell chip he'd bought years earlier "for exactly this kind of emergency."
Okabe's contribution came at naming time. A three-outlet strip is a three-headed guardian; a three-headed guardian is Kerberos; and a power strip named Kerberos requires — requires — that commands be delivered as invocations. The syntax stuck because it works: the recognizer's accuracy is measurably higher on Okabe's declaimed "KERBEROS!" than on anyone's normal speaking voice, a fact Daru has verified, resents, and cannot explain.
Command vocabulary
- "First/Second/Third head, wake"
- "First/Second/Third head, sleep"
- "All heads, wake"
- "All heads, sleep"
- "Guard" — all off after 60 s (the "leaving the lab" command)
| Parameter | Value | Notes |
|---|---|---|
| Relay channels | 3 | 1500 W each, audible clunk |
| Recognition chip | HM2007-derivative | Trained per-speaker |
| Vocabulary slots | 12 (9 used) | 3 reserved "for the future" |
| Wake-word accuracy | 94% | The one thing it hears reliably |
| Full-command accuracy | 71% | Lab-quiet conditions |
| False triggers | ~2/month | See incident table |
| Standby draw | 1.1 W | The hound never sleeps |
Channel relays are mechanical and loud by design — Daru wanted unambiguous physical confirmation, having read enough SERN archive material to distrust silent switching forever. The clunk is audible through the floor in the Braun Tube Workshop, whose proprietor has learned to interpret the lab's day from its rhythm.
Documented causes include: a TV documentary about Greek mythology; a customer downstairs sneezing with unusual commitment; and Mayuri reading a picture book aloud, which powered down the soldering iron mid-joint. The phrase "care-bear-os" is now banned in the lab under statute #wip.
For one winter the third head fed a rice cooker, making "Kerberos! Third head, wake!" the lab's lunch bell. Decommissioned after the cooker's own electronics interpreted a brownout as a menu change and produced what the log calls "congee, adversarial."
At 12% accuracy in convention noise, the demo devolved into Okabe shouting mythology at an unresponsive power strip for four minutes — which drew a bigger crowd than any working demo the lab has run. Three people asked where to buy one. Validation, again.
Kurisu's notebook entry: "It's a relay board with a doorbell chip. Anyone in earshot can command it. Your threat model is 'roommates.'" Daru's appended rebuttal: "Threat model is bench ergonomics, and the hound has never once made me move the IBN." No further review was filed. The exchange is preserved in the handbook as the canonical example of requirements disagreement.
The speech chip's lineage is documented at Speech recognition; the mythology at Cerberus. Within the FG line, the Tap continues the Moad Snake's quiet doctrine — a real tool wearing a costume — and its three reserved vocabulary slots are the lab's most honest roadmap: capacity for the future, contents unknown. A proposed fourth relay ("the head Hades removed") is tracked as the red link fourth head proposal.