Nixie tube watches have a novel aesthetic. These watches have a few tubes that warmly glow with numbers. Impressed by these watches, Lucas Volwater designed a wristwatch with no numbers. As a substitute, the Neon Watch makes use of 4 neon tubes to create a show that mimics an analog watch face with a twist.
The key to creating the watch face work is that every neon lamp has two electrodes. By activating them independently or collectively, 4 lamps create 12 positions. For instance, the lamp on the 12 o’clock place makes use of each electrodes to point the “12” place. For the “1” place, solely the appropriate proper electrode of the identical lamp illuminates. This technique means the watch can solely show a single digit at a time. So the watch reveals hours after which minutes as two “digits.”
4 hour marks with two Neon Tubes
Volwater designed the watch with a Microchip ATmega48A microcontroller (MCU). Whereas this 8-bit MCU doesn’t have a real-time clock, you need to use one among its counters as a “real-time counter” with a devoted 32.768 kHz crystal as a timekeeper. The draw back to this strategy is that if the (solely) battery dies, the wearer should reset the time. Thankfully, the 110 mAh battery lasts simply over 4 days.
The Neon Lamps usually keep off to preserve the battery. Nonetheless, there are not any buttons to activate the lamps, nor are there any to set the time! As a substitute, an OSRAM SFH320 phototransistor serves each features. First, the MCU illuminates the show for 16 seconds when the sensor detects a easy hand wave. And the opposite use is programming the time.
Setting time by way of gentle (📷: Eluke.nl)
In 1994, Timex launched the Datalink. It was the primary watch that downloaded knowledge from computer systems “wirelessly.” An optical sensor detected flashing patterns from a CRT (or an non-compulsory adapter with an LED.) Equally, Neon Watch makes use of the SFH320 phototransistor to switch knowledge. An software on the PC makes a flashing sample that the Neon Watch decodes as the present time!
The parts all match on a single spherical PCB with a 40-millimeter diameter. Contained in the case, there are solely 9 millimeters of top out there. The clear cowl takes up 2 millimeters, and the neon lamps have a 4 millimeter diameter. Volwater realized that these parts, plus a battery, did not match throughout the constraints. So, the PCB is simply 0.8 millimeters thick as a substitute of the standard 1.6 millimeters, permitting every thing to suit.
PCB Again. T1 (prime left) is miniature transformer (📷: Eluke.nl)
One other tall element can also be crucial for working the enhance converter for the Neon lamps. It’s a miniature transformer. Whereas these will not be manufactured right now, at one level, they have been plentiful. Their authentic software was a part of the cost circuit utilized in digital camera flashes.
For added photos, try Volwater’s Neon Watch weblog publish. There are additionally movies of it demonstrating the time show and transferring knowledge.