wound by daylight noise

The spring

Eight turns of the crank wind it from nothing to full, at any setting. Each tick the clock runs takes a little of that back. The lit coil round the crank is what's left, running out from the hub to its hook, and a faint mark on it shows where it starts to fall.

The crank: clockwise winds it. Back the other way lets it down through your hand, so under the mark you can rock it and bend the whole rack's pitch.

RATE: the tempo at full wind, 120 at noon. At full, 1920 beats a minute: the wheels aren't a rhythm any more, they're a low note.

SPRING: how long a full wind lasts. Up full, ten minutes at 120. Eight bars is a third of the way up. Right down, a turn is a beat and there's hardly any spring: you're the clock, and when you stop, it stops.

FUSEE: how much of the wind stays steady. At noon it holds till under a fifth is left. Fully left it's the raw spring, falling from the first beat. At full it doesn't move until the last few beats, then it goes off an edge.

The fall

Under the mark the tempo falls in a straight line, the way a record does. SAG is that speed as pitch. Run every oscillator from it and they all go down together with the clock.

SAG, the knob: how far. At noon it's a true record: half the speed is an octave down. At full, two octaves, and five before it's done. Fully left the pitch stays put and only the clock drags.

TUNE: a pitch in, added to SAG, so a sequenced line rides the spring.

WEAR: the clock's age. A little human wow at noon. Up from there it's out of beat, every second tick late, and at full the ticks wander and the broken teeth trip the train, and every pitch stumbles with it.

The last moments

CLAP: a trigger that fires at random in the last moments, up to three to a run-down. Each one kills a wheel, and its lamp goes out. It stays dead until you've wound it all the way, so half a wind brings back half a band.

Past full: keep winding and it runs fast, then it jumps a tooth: a lurch, a roll through the wheels, a beat skipped, some of the wind thrown back. Then it finds itself.

What winds it

WIND: each pulse is one turn of the crank, so a slow pulse can keep it alive. Put another clock in with SPRING right down and it follows that clock, and when that clock stops the rack runs down over a few beats instead of stopping dead.

STOP: a thumb on the train. It drags to a halt with the spring still wound, and spins back up when the gate lets go.

What comes out

Five wheels on one train, named for the wheels of a real clock. Each stays high for the first half of its own turn, so when the train drags, the gates drag too.

GREAT: every four ticks. CENTRE: every two.

TICK: the tick.

FOURTH: two to the tick. ESCAPE: four.

SAG: the speed as pitch, with TUNE added.

TENSION: the spring, 0 to 8 V, for anything that should run out with it.

CLAP: the bang.

Inside

The crank is printed: a click wheel and its arm on a brass shaft, the shaft in two ball bearings held in two cups clamped through the panel, and on its back end a magnet over a sensor on the board, 1.3 mm away. One board sits 10 mm behind the panel, everything on its front. The coil's 45 LEDs light a white printed channel, so the spring reads as one line. Turned round, the panel lights from a second set, through a second baffle.

The WOUND panel: a brass gramophone horn in gold dots filling it, the spiral spring in its throat lit a bit over half way out from the hub, the printed crank over it.

Drag it or use the arrow keys to turn it; click it to take it apart.

Specs

Format

Width: 20 HP
Depth: 20.8 mm behind the panel; the crank's handle stands 38.6 mm in front, 23.3 folded
+12 V: about 45 mA at boot, 95 mA running, 190 mA at the most (estimated)
−12 V: about 7 mA (estimated)
+5 V: not used
Controls: a crank on two ball bearings, a big knob, 4 knobs

I/O

WIND: gate, past 1.5 V: a pulse a turn
STOP: gate, past 1.5 V
TUNE: 1 V an octave, added to SAG in the analogue stage, within 2.4 cents an octave
Wheels: GREAT, CENTRE, TICK, FOURTH, ESCAPE: clocks, 0/5 V
CLAP: trigger, 0/5 V, 10 ms
SAG: 1 V an octave, +3 to −5 V, plus TUNE
TENSION: CV, 0 to 8 V, 10 V overwound

Engine

Brain: RP2350, 64-bit float, 4,000 steps a second
The crank: a magnet on the shaft over a sensor, 16,384 counts a turn, read every step
The wheels: each edge where the train turned, to the nearest 7 ns, 1 ms behind the spring
Light: 45 white LEDs along the coil, a lamp by each wheel, two pallets; a second set for the panel turned round
Power cycle: nothing kept: it wakes run down