# Sweeping second hand on Quartz watches- do they exist?



## james brodie

They certainly do on clocks...


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## Autonomous

Bulova Precisionist..? not 100% sure


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## RSR934

Hi james brodie.

I have a couple of Bulova Accutron II's, they are quartz and have a sweeping second hand. :thumbsup:



Autonomous said:


> Bulova Precisionist..? not 100% sure


 You beat me to it. :yes:


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## WRENCH

Bulova UHF.


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## mach 0.0013137

Autonomous said:


> Bulova Precisionist


 Yep, smooth as silk...


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## james brodie

Cool! Look so much classier


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## Autonomous

Hi @james brodie I don't mean to hijack your thread but does anyone have a definitive answer as to why? Certainly @WRENCH and @mach 0.0013137 seem to be erudite gentlemen... does it really have to be an ultra high frequency movement to produce a sweep as such??


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## RSR934

Hi Autonomous and james brodie.

Bulova Accutron II watches, Bulova prints "262 KHz" which is the frequency of these UHF quartz movements. Your standard mechanical watch operates at between about 3-5Hz - which is good for accuracy of just a few seconds a day. Your standard electronic quartz movement operates at 32,728 Hz (32.728 KHz) which offers accuracy of a few seconds per month. The Bulova UHF quartz movements operate at 262 KHz, which offers accuracy of a few seconds per year. The UHF movements also offer sweeping seconds hands similar to those in mechanical watches and they have a battery life of about two years.

Hope this helps.

Regards Paul. :thumbsup:


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## MyrridinEmrys

I believe that the stepper motor in a traditional quartz mechanism would consume a battery quite quickly if it 'stepped' multiple times a second to produce a sweeping motion . So, the once a second, seconds hand movement is likely a power saving feature.


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## james brodie

If battery consumption would be prohibited it seems great opportunity for the Kinetic/ Solar designers to get to work imo. Always thought quartz movement looked tacky


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## Autonomous

WRENCH said:


> Bulova UHF.


 That's a particularly good looking one, think there's room in my box for an example!



james brodie said:


> If battery consumption would be prohibited it seems great opportunity for the Kinetic/ Solar designers to get to work imo. Always thought quartz movement looked tacky


 I agree. I am surprised no one else came up with it before Bulova


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## Tom-HK

The frequency of the quartz oscillator has nothing to do with how many times the second hand moves. The early Beta 21 movements had XOs oscillating at a mere 8 kHz and yet their second hands moved even more smoothly than those of the Bulovas due to the way in which their mechanics worked.

Over the years there have been watches with 8 kHz, 16 kHz, 32 kHz, 40 kHz, 196 kHz, 262 kHz, 2.4 MHz and 4.2 MHz. Almost all analogue quartz watches, regardless of frequency, use dead-beat second hands for power-saving reasons, as someone has already pointed out.

These days, of course, we have moved on from the direct drive nature of the Beta 21 and all analogue quartz watches today use stepper motors. These can be programmed to 'fire' as many times per second as the manufacturer wants. The 16 beats per second of the Bulova watches is pretty darned smooth but does, of course, still result in a faintly noticeable progression of steps. They could have gone for more beats and an even smoother motion, but ultimately I think they had to consider battery life (even with the giant battery that they use in those watches) and I guess they compromised at 16 beats, which is almost imperceptible.

For even smoother second hands you would have to turn to Seiko. No longer produced but still turning up on the second hand market from time to time, Seiko cals 5S21 and 5S42 have 4 beats per second and employ viscous dampeners to iron out the ticks into a completely smooth movement.


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## Chromejob

james brodie said:


> They certainly do on clocks...


 By "sweep" do you mean a smooth action, more than 6 or 8 beats per second? Y'might want to look up the Omega F300 line of "hummers" from the 1970s. At one time I really wanted one, several forum members showed theirs regularly on the Sunday Oldies threads.

As mentioned, Bulova have a contemporary line that move smoothly, too.


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## Autonomous

Tom-HK said:


> The frequency of the quartz oscillator has nothing to do with how many times the second hand moves. The early Beta 21 movements had XOs oscillating at a mere 8 kHz and yet their second hands moved even more smoothly than those of the Bulovas due to the way in which their mechanics worked.
> 
> Over the years there have been watches with 8 kHz, 16 kHz, 32 kHz, 40 kHz, 196 kHz, 262 kHz, 2.4 MHz and 4.2 MHz. Almost all analogue quartz watches, regardless of frequency, use dead-beat second hands for power-saving reasons, as someone has already pointed out.
> 
> These days, of course, we have moved on from the direct drive nature of the Beta 21 and all analogue quartz watches today use stepper motors. These can be programmed to 'fire' as many times per second as the manufacturer wants. The 16 beats per second of the Bulova watches is pretty darned smooth but does, of course, still result in a faintly noticeable progression of steps. They could have gone for more beats and an even smoother motion, but ultimately I think they had to consider battery life (even with the giant battery that they use in those watches) and I guess they compromised at 16 beats, which is almost imperceptible.
> 
> For even smoother second hands you would have to turn to Seiko. No longer produced but still turning up on the second hand market from time to time, Seiko cals 5S21 and 5S42 have 4 beats per second and employ viscous dampeners to iron out the ticks into a completely smooth movement.


 Thanks, that's what I call an answer :thumbsup: ... so there's no barrier to it being done, but most manufacturers don't bother. I think it's a shame because even the same sweep as a regular mechanical would be better than a 'tick' that doesn't even hit the markers, in my opinion.


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## Rab

As others have pointed out, a standard quartz crystal oscillates at 32,768Hz, if you powered the watch from a car battery, you could have the second hand move 32,768 times per second, heat build up from friction might be an issue and the teeth on the gears would need to be tiny (or the gear be very large) but in theory you could do it.

The Bulova watches oscillate at 262,144Hz (8 times faster), but this does not make them inherently any more accurate than a standard quartz, an error of say 0.5% would translate to the same timekeeping error regardless of the frequency of the quartz crystal, I can only assume that Bulova's 3 pronged crystal allows them to trim to a tighter tolerance than the standard 2 prong types.

So, you could have a super smooth quartz second hand, but you'd need to carry the battery in a rucksack and the gear would be spinning fast enough to cut glass.

The weird frequency value of the oscillators come from the ease with which they can be binary divided (which microchips like), so 32768 = 2^15, 262144 = 2^18.


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## Sparky

Yes, this one certainly does:

Record "De Luxe" (Uses a Record-Golay FB 7723 movement - More details here: http://www.crazywatches.pl/mirexal-golay-fb7723-quartz-1972). Crown at 4pm only changes the date. There is a crown on the back that alters the time!

2018-03-28_08-50-27 by mcridland, on Flickr

Mark


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## mel

The limitation is the power cell. Almost completely smooth *clocks* can be produced relatively cheaply, but there's room to use a chunky big cell(s).

Persistence of vision also helps - - as in movies and/or TV - - animations or individual pictures that are moved around 25 times per second produce the illusion of continuous movement. (What spiffing fun we all had in school drawing stick men doing rude things on the corner of the books then flicking the pages to produce the effect)

So *only* 25 "ticks" per second will produce a reasonable semblance of continuous movement and this applies however the movement is driven, Quartz, hybrid Electromech or Mechanical. Some makers do it better than others. Others don't even try 

It's how you produce 25 movemnets every second that consumes all the power.


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## gimli

As others have said battery life is one concern but accuracy is also a factor. Faster "beat rates" usually result in lower accuracy.

Electronic/hummer/tuning fork movements have a better accuracy than the usual mechanical watches (both types can be regulated as well) but the quartz will usually have better accuracy and the costs of manufacturing are also lower so I guess people went with a ticking seconds hand for financial reasons. Theoretically a movement with a sweeping seconds hand will also break down faster and/or require servicing more than a quartz does. Then again many quartz watches these days are simply replaced or, at the very least, have the entire movement replaced rather than serviced.


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## Chromejob

Sparky said:


> http://www.crazywatches.pl/mirexal-golay-fb7723-quartz-1972


 Let me fix that for you (all).


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## Autonomous

mel said:


> The limitation is the power cell. Almost completely smooth *clocks* can be produced relatively cheaply, but there's room to use a chunky big cell(s).
> 
> Persistence of vision also helps - - as in movies and/or TV - - animations or individual pictures that are moved around 25 times per second produce the illusion of continuous movement. (What spiffing fun we all had in school drawing stick men doing rude things on the corner of the books then flicking the pages to produce the effect)
> 
> So *only* 25 "ticks" per second will produce a reasonable semblance of continuous movement and this applies however the movement is driven, Quartz, hybrid Electromech or Mechanical. Some makers do it better than others. Others don't even try
> 
> It's how you produce 25 movemnets every second that consumes all the power.


 That all sounds very reasonable, but would it take so much power to create 6-8 movements a second... does it really have to be so smooth the movements are imperceptible? I'm just wondering why they never sought to replicate the movement of a standard mechanical second hand.


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## alxbly

As already mentioned, the Bulova high frequency watches are pretty smooth:






Surprised other high end quartz watches haven't followed... That said, I think some mecha-quartz also have a smooth sweep, maybe someone else can confirm?


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## reggie747

Grand Seiko Spring Drive anyone ?? :biggrin:


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## Chromejob

reggie747 said:


> Grand Seiko Spring Drive anyone ?? :biggrin:


 Had that in my reply until I remembered it's not a quartz movement, per se. It's mechanical with some electrical components IIRC.

https://en.wikipedia.org/wiki/Spring_Drive

https://www.grand-seiko.com/global-en/about/movement/springdrive/


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## Sparky

Chromejob said:


> Let me fix that for you (all).


 Great, thanks very much

Mark


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## Tangent

Does the Longines VHP have a sweeping hand?


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## RWP

Precisionist battery life I have found isn't more than a year  , and they are big lithium batteries.


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## Filterlab

RWP said:


> Precisionist battery life I have found isn't more than a year  , and they are big lithium batteries.


 I have a 98b212 which has the option to switch on or off the sweep when the chrono is not in use. I turn it off when I'm not wearing it. It was new in November so I'll see how it goes. I do use the chrono a fair bit though.

I do love the sweeping seconds though, very nice to look at.


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