How does it work? (Accutron Spaceview 2020)
The engineer nerd in me had to research how this thing works after I received one this week.
The Spaceview 2020 is a recent new release and unique horology tech. It is a battery-less, arm motion powered, quartz accurate watch developed in Miyota labs and marketed through Accutron. It is most commonly compared to springdrive due to its accuracy, smooth motion second hand, and automatic-movement type power supply. Marketed as a follow on to Accutron Spaceview 214 tuning fork technology of the 60’s, it actually has very little in common beyond the shape of the hands, color scheme and skeletal view.
This Spaceview 2020 is a new and unique horology tech, but outside of the horology world, the 2020 energy generation and release tech actually dates back to before tourbillions were bleeding edge, and marries it with 1970’s quartz regulation.
The 2 electrostatic generators, used to generate electricity are a form of a Wimshurst machine, belonging to a class of machines called influence machines.
Influence machines are a frictionless static electricity generator that began to appear around 1788.
Wimshurst machine (pronounced Wimz-hurst) was invented in 1883 by British inventor James Wimshurst, while improving upon many earlier influence machines of that era. The key aspect of this engine is two disks mechanically rotating in opposite directions accumulates static electrical charge. Details of how a Wimshurst machine works can found in this excellent video:
[https://youtu.be/Zilvl9tS0Og?si=I-caAPgrZuuTArDc]
Related influence engine descriptions can be found on this Wikipedia page:
[https://en.wikipedia.org/wiki/Electrostatic_generator#]
The 2020 has a weighted oscillator (rotor) very much like one found in an automatic watch. There is a direct correlation between the rotational direction and momentum of this weighted rotor and the spin of the two electrostatic generators. The watch rotor provides the mechanical motion required by the Wimshurst engines.
Unlike a springdrive and classic automatic that stores kinetic energy into a mainspring, the 2020 converts the kinetic energy directly into electricity and stores it into a capacitor (like a self charging rechargeable battery)
The watch speed is regulated by the fixed frequency vibration of a quartz crystal. A quartz crystal requires electricity to induce vibration. The electricity is drawn from the capacitor.
The large wheel is an electrostatic motor, or more specifically a corona-discharge motor. It is a direct drive for the second hand, and only moves when the second hand is moving. It does not drive the hour or minute hands.
In fact in the 2020, it will visibly only run for 5 minutes after the watch has been in motion, after which the second hand will stop at 12 o’clock to conserve power. The hour and minute hands do continue to move and are independent of the second hand. The hour and minute hand will continue to move up to 10 days after the watch has seen no movement, before shutting down. Those thinking in automatic watch terms, might call this a 240 hour power reserve.
Here is a video of a corona-discharge electrostatic motor being powered by a Wimshurst.
[https://youtu.be/9uEjXsX1F14?si=KHtcKfOTe7CwNzk9 ]
In simplest of terms, it’s similar to the 2020 generators powering the second motor, without quartz regulation.
Regarding accuracy, the 2020 is a battery-less smooth movement quartz watch. Citizen is the premier master of precision quartz closely followed by GS. The claimed precision of this watch is 5 seconds per month, though I won’t be surprised if they pad their error margin by an order of magnitude like GS does. I don’t have enough data yet to voice results other than to say the first few days are spot on.
I’m a software engineer and watch enthusiast. I’m not excited about brand or heritage, but rather engineering tech.... spring drive, solar GPS, electrostatic drive, transistor tuning fork regulation,...
Yeah I’ve been eyeballing this watch on eBay. They are not cheap but I would love to have one. Any watch that uses proprietary movements is a win in my book.
Yeah I’ve been eyeballing this watch on eBay. They are not cheap but I would love to have one. Any watch that uses proprietary movements is a win in my book.
I’ll admit I was drawn in solely by the unique tech. Yeah, they’re not cheap, and seem to be getting more expensive with the third round of releases. I picked up my new one on chrono24 for a minor discount, which I assume the jeweler was just making room for new versions.
I very much would like something like this. Meaning this or a past or future version.
This is fantastic. Thanks for posting it on the other thread.
Question: Does the second hand move back to the correct position following a period stopped at 12? Or do you end up with the second hand passing 12 out of sync with minute hand passing the minute markers?
This is fantastic. Thanks for posting it on the other thread.
Question: Does the second hand move back to the correct position following a period stopped at 12? Or do you end up with the second hand passing 12 out of sync with minute hand passing the minute markers?
When the second hand re-engages out of power save mode, it runs at half speed until real time catches up to it. In that way, you can tell it’s in the processes of sync’ing.
That’s a pretty neat solution. I guess another would be to have the second hand only start when the minute hand hits a minute marker. I hope they roll this movement out to more watches. It’s a cool reissue of the original Accutron design, but I would love a movement like this in a vintage, explorer style, GADA watch.