/fa/ - Fashion

>>14040546

>>14017286

>>13927229

>>13877208
> Only 5Hz

>>13870378
There are certainly some citizen watches that are historically important technically.

>>13827591
>interesting, quirky Citizens

>>13639106
You can see the magnet that was part of the balance in both that webm and, to some extent, this webm of a 43,200bph cosmotron 5800. The 5800 was primarily used in ladies watches and was at the time (and for a long while after) the fastest-beating commercially released hairspring-regulated watch. One thing to note though is that the escapement used in these watches is fairly different from that used in traditional hairspring watches. Instead of the mainspring driving the geartrain and the escapement stopping it, in these the escapement pushes the geartrain forward - in some ways, it has more in common with the escapement design (index wheel and pawl) of an accutron tuning fork watch. As a result, the geartrain is not under constant load the way it is in a traditional mechanical watch, and so wears much less quickly, which is also a factor in allowing the much higher beat rates. The different escapement design in the cosmotrons also means that the second hand only advances once per complete oscillation of the balance, so from the front the watch looks like a 21,600bph watch in terms of how smoothly the second hand advances.

>>13599667
5/5
This is a citizen cosmotron cal 5800. The cosmotrons are electric watches that use a hairspring to keep time. The Hamilton electric was the first electric watch, but had some reliability and serviceability issues. Citizen's cosmotron series came much later but was extremely successful. The cal 5800 ran at 43,200bph, which was the highest beat rate of any series-produced hairspring-regulated watch in history for a long time. The 5800 was a ladies-sized movement, although it was found in a few men's models. A system of electromagnets provides the impulse to keep the balance turning, instead of the standard mainspring. As a result, there is no power being transmitted through the geartrain like there would be in a traditional watch, meaningfully reducing the servicing requirements.

For a long time, the citizen 5800 was the hairspring-regulated watch with the fastest beat rate in the world, at 43,200bph. However, because of the design of the escapement, it did not have the fastest-beating second hand. While most hairspring watches are driven by the mainspring, electric watches are driven from the balance wheel. This has a number of advantages - the much lower torque in the geartrain is a big one, since it results in less wear on the parts. One consequence is that the escapement design is generally different. In the Citizen electronic watches, an indexing system is used which only advances the hands every other oscillation. As a result, the hand ticks 6 times per second, compared to the 12 times you'd expect from a 43,200bph balance with a swiss lever escapement. As a result, the 36k 32A from 1966 still held the record for fastest beating hairspring-regulated watch for a long, long time.

>>13530584
Hm.

>>13506642
>>13506656