Cyclochron LED Ring-Clock

The Cyclochron is a LED clock or ring clock. It shows the time on a single circular ring display that consists of 60 LEDs. Many types of circular LED clocks have been built, but this one is unique in that it only has a single ring that is used to display time.

How is this done? Instead of a single LED that is turned on to show a point that is equivalent to a clock hand, it uses simulated rippling motion, often called a "chaser". We are all familiar with a row of lights that are flashed in sequence to give the appearance of motion. A theatre marquee or outdoor advertisements often use such "chaser" patterns to attract attention.

In the Cyclochron the LEDs are flashed in a sequence like this, but in two different directions. The ripple chaser effect emerges at the minute-hand point and travels outward in two directions, and then converges on the hour-hand point. When you look at the display you have to visualise the positions of the two hands by observing the emerging point and the converging point. So that you don't reverse the association, a little mnemonic aid is used: Minutes turn into hours.

The hour-hand position is accurately interpolated between the hour marks. At 6:45 the hour point is 3/4 of the way between the six and the seven. This simulates a mechanical clock. Many simple LED ring clocks do not do this because they can't -- they only have a single LED for the hour, so at 8:59 it looks almost like 8:00. That's pretty confusing.

When the two points get quite close, it is harder to see exactly where the points are, so the LEDs for the two points actually come on and illuminate steadily to help you find their position easier. (One of the alternate modes of operation (Easy Read) allows these "helper" LEDs to be on at all times.)

A conceptually interesting event occurs twenty-two times each day, which is when the minute hand approaches, overlaps and then overtakes the hour hand position. Since the minute position is always the emerging point for ripple patterns, the predominant direction just before the hands overlap is anti-clockwise. After the hands overlap, and the minute hand moves away from the hour hand point, the predominant direction will be clockwise. What happens when they exactly overlap? This case is a special event, lasting exactly one minute, where the speed of the chaser pattern gradually slows down until it stops, then reverses direction and gradually speeds up again. This is a fun event to watch for and point out to visitors.

Besides the chaser patterns, the Cyclochron has a totally different mode of operation that is closer to a real clock metaphor. We call it the All Hands mode. The hour position is shown by a single steady LED, the second-hand is shown by a single LED that steps around the display and the minute position is shown by a three-LED group that has its own three-stage chaser sequence.

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Controls. There are three buttons behind the faceplate that require a stylus or bent paper clip to access (they could be relocated or exchanged with magnetic reed switches, for example). They are REV (reverse), SET and FWD (forward). The SET button cycles through five different setting steps, then returns to the clock display.

REV button (left)	SET button step	FWD button (right)	display indication
set am or PM	1. set am/pm	set am or PM	3 LEDs to left or right of 12 o'clock point, alternate.
reverse hour	2. set hour	forward hour	one steady LED in one of the 12 hour points.
reverse minute	3. set minute	forward minute	one flashing LED in one of 60 points.
occurrence level	4. program chime occurrence level	chime hour affected	3 LEDs to left or right of 12 o'clock point (for am or pm). These flash to indicate chime sounding 4x per hour, 2x per hour, 1x per hour, or silent. for that hour. Plus 1 LED at each of the 12 hours points marks the hour. Starts at 12:00 am (00:00) and steps through all 24 hours. (see notes below). REV and FWD buttons have different functions, not related to forward or reverse.
mode selection	5. display mode	mode selection	6 LEDs in one of four quadrants indicate 1 of 4 modes

Display Modes. The normal mode is the chaser, with the helper LEDs appearing at the minute and hour points when they are rather close together. A second mode, Easy Read, can turn these helper LEDs on all of the time. The third mode, All Hands (described above), does not use the chaser, but shows three distinctive points for hour, minute and second. And the fourth mode alternates between normal and All Hands, each on for about eight seconds.

Display Variations. The display also has variations to the basic chaser. These are part of a performance program that enables different variations at specific points in a 30-minute cycle. Among the variations are three different speeds, a sweep-clean mode that periodically sweeps the chaser clean, only to be rebuilt again, a Mobius chaser, and a very unique stop-modulate mode where the chaser stops momentarily while all the LEDs do an intensity modulation (flicker) effect, followed by a return to the normal chaser. Learning when these variations occur can also help identify the precise minute, since in the Movado tradition, there are no markings on the face of the clock.

Chime Tone. The LED display is already unique, but add to that a totally new chime tone system created for this clock. It uses melodic beeps of just two different musical pitches, but played in rhythmic groups that makes it easy to count the hours. The rhythmic grouping forms a Gestalt unit that can make it possible to replay the sequence from memory even if you were not paying full attention the first time. More info on this can be seen and heard HERE. The occurrence level (every 15 minutes, every 30 minutes, only on the hour and silence for the hour) can be programmed for each hour of the 24-hour cycle. This is the reason for the am/pm indication in the setting modes.

Power Requirements . The Cyclochron operates from a 12 Volt AC power adaptor or "wallwart" (not supplied). The power unit is best obtained it your country so that it meets local safery regulations and is compatible with the voltage, frequency and plug style specific to your country.

Battery Backup. It contains two 3v lithium batteries (not supplied) for running the timekeeping during short power failures. During power failures the display is off. After eight minutes the timekeeping is lost and the clock will have to be set again. This is intended to preserve the batteries. The display mode and chime tone occurrence settings are not lost during longer power failures if battery backup is used.

The Cyclochron was designed in 1991, but only three units were produced. A new revision is available now, with newly designed cases. Only 20 units are being produced due to the design being based on a component that is no longer manufactured.