Why is there no sweep second hand in a quartz watch?

[Flaxmoore]

I admit I'm a relative newcomer at this, but something's bothering me.

The smoothness of sweep for a watch second hand is partly influenced by the beat rate of the movement. 28.8K is nice and smooth, 21.6K less so, 14.4K stutters a bit, like this junker a friend let me have to see how it works.

Considering that's beats per hour, it makes sense. Each "jump" of the second hand takes 1/6 of a second, faster than the "shutter speed" of the eye.

However, the beat rate of a quartz movement is 32K per second. Blindingly fast compared to mechanical. Why isn't there a glass-smooth sweep second hand quartz watch? What am I missing?

[Skutt50]

The beat rate in a mechanical watch is transfered mechanically to the second hand.

The 32K in a quartz movement is an oscillation frequency which isn't mechanically transfered to the second hand. There are electronics involved. To refer to it as beat rate is in my opinion not correct. It should be oscillation frequency.

Also you are comparing a beat rate of 28.8k per HOUR with an oscillation frequency of 32k per SECOND.

[Flaxmoore]

The beat rate in a mechanical watch is transfered mechanically to the second hand.

The 32K in a quartz movement is an oscillation frequency which isn't mechanically transfered to the second hand. There are electronics involved. To refer to it as beat rate is in my opinion not correct. It should be oscillation frequency.

Also you are comparing a beat rate of 28.8k per HOUR with an oscillation frequency of 32k per SECOND.

I know I compared oscillations per hour to beats per second. That was intentional.

However, why couldn't the electronics in a quartz be used to provide a sweeping hand? Seems as if it would be easier.

[nylawbiz]

It's the nature of analog vs. digital technology. Digital is yes/no; on/off; 1/0. Nothing in between. Everything incremental. Analog technology is continuous; as in the uncoiling of a spring. A constant movement; that is translated into the ratcheting of teeth in a gear. Does that make sense?

[Flaxmoore]

It's the nature of analog vs. digital technology. Digital is yes/no; on/off; 1/0. Nothing in between. Everything incremental. Analog technology is continuous; as in the uncoiling of a spring. A constant movement; that is translated into the ratcheting of teeth in a gear. Does that make sense?

It makes perfect sense, but there is one problem. Why is the on/off set at 1 second intervals? It seems as if it would be a fairly simple matter to set it to 1/10 second, or even 1/6 to keep it in base 60.

[nylawbiz]

It makes perfect sense, but there is one problem. Why is the on/off set at 1 second intervals? It seems as if it would be a fairly simple matter to set it to 1/10 second, or even 1/6 to keep it in base 60.

Not sure, but I would venture to guess it has to do with the limitations of the mechanics of the watch.

[diablojota]

Think about the consumption of battery power if you changed the interval settings from 1 sec to 1/10 of a second. This would increase the amount of time that the signal sent goes from 0 to 1 (off to on) tremendously leading to a much larger increase in the battery usage. You would in turn get probably about 1/10th the battery life then... Just my thought.

[Tools]

Think about the consumption of battery power if you changed the interval settings from 1 sec to 1/10 of a second. This would increase the amount of time that the signal sent goes from 0 to 1 (off to on) tremendously leading to a much larger increase in the battery usage. You would in turn get probably about 1/10th the battery life then... Just my thought.

That's exactly it........ The motor to actually drive the watch hands is only pulsed once per second.

Of course, battery technology has come a long way now and it probably won't be long before quartz makers take the next step and smooth out that handsweep the way AC driven clocks are at only 60 cycles per second..

[Flaxmoore]

That's exactly it........ The motor to actually drive the watch hands is only pulsed once per second.

Of course, battery technology has come a long way now and it probably won't be long before quartz makers take the next step and smooth out that handsweep the way AC driven clocks are at only 60 cycles per second..

I actually wonder what would happen if Citizen got the Eco-Drive right, or if a true mechanical/battery hybrid existed. It could conceivably run forever.

[Solo118]

I had a Pulsar about 10 years ago that was quartz, and when you start the chrono it moved very smooth without "ticking" I wonder if that is what you are talking about?

[Mathemagician]

I've got a quartz Seiko from 20+ years ago (rode my bike to a 90% off going out of business sale at a jeweler and picked it up for about $40 IIRC) with hands that move pretty smoothly either when using chrono or changing modes. Some barely perceptible ticking. No second hand, though, and I guess that's why. Thing is pretty nifty to this day and still runs just fine, though the lume is long dead.

[johnswatch]

The quartz Patek Aquanaut has a smooth sweep but needs a new battery every 18 months. Battery life is the reason you don't get smooth sweeps on most quartz watches (Seiko spring drive excepted)

[gregdolley]

It makes perfect sense, but there is one problem. Why is the on/off set at 1 second intervals? It seems as if it would be a fairly simple matter to set it to 1/10 second, or even 1/6 to keep it in base 60.

I heard that it's once every second to conserve battery life.

[postiff]

I have a quarts watch i got off ebay that runs very smooth.

[gregdolley]

I actually wonder what would happen if Citizen got the Eco-Drive right, or if a true mechanical/battery hybrid existed. It could conceivably run forever.

Check out the Seiko spring-drive to see an interesting mechanical/electro-magnetic hybrid. It also has a _very_ smooth sweep.

[goduke1]

Check out the Seiko spring-drive to see an interesting mechanical/electro-magnetic hybrid. It also has a _very_ smooth sweep.

X2 It is very smooth!

[cwru32]

It's the nature of analog vs. digital technology. Digital is yes/no; on/off; 1/0. Nothing in between. Everything incremental. Analog technology is continuous; as in the uncoiling of a spring. A constant movement; that is translated into the ratcheting of teeth in a gear. Does that make sense?

wow smart lawyer !! i liked ur movie! :cheers:

[gioarmani7428]

Very interesting stuff!

[watchmaker]

I can't recall the model off hand, but ETA manufacture a line of quartz movements with sweep centre seconds. I could check the reference next week if anyone is that interested.

[Nods]

I actually wonder what would happen if Citizen got the Eco-Drive right, or if a true mechanical/battery hybrid existed. It could conceivably run forever.


I saw an add for GMT type Eco-Drive earlier this year and it was boasting a 3 year battery reserve. So I believe that they may have the Technology/battery to do the smooth sweep. It would be interesting to see one of those watches running.

[Stanley Lyndon]

I am intrigued by this video I saw today:

http://www.youtube.com/watch?v=M2FkD1QUc4w

It has a quartz movement cal. 5100 with sweeping second hand?

[Nods]

I am intrigued by this video I saw today:

http://www.youtube.com/watch?v=M2FkD1QUc4w

It has a quartz movement cal. 5100 with sweeping second hand?


It had to happen soon, good that Rolex did it first! (to my limited knowledge anyway) I wonder what the battery life is, rather short I suspect.
:thinking:

[swatty]

I am intrigued by this video I saw today:

http://www.youtube.com/watch?v=M2FkD1QUc4w

It has a quartz movement cal. 5100 with sweeping second hand?

Never seen this :thinking: