On Wed, 18 Sep 2013 23:01:08 -0400 Gary Hurst <jabbahur...@gmail.com> wrote:
> dickarde says it is the precision cut of the crystal that makes extreme > accuracy possible and few will go to the trouble to cut it absolutely > perfect to get sub 10 seconds when 20 or 30 can be achieved so much more > easily and, for all practical purposes, just as good. the only watches > that could do it with any regularity would be something such as the > rolex oysterquartz, which was cut with extreme care. > > bulova solved the problem differently. one problem of the quartz watch > is the battery drain as it ticks. the steps are taken in whole seconds > as otherwise you'd be going through batteries too frequently. you have > more inherent accuracy if you take more steps per second, as a > mechanical watch that takes 10 beats per second is inherently more > accurate than one that takes 6. bulova has solved the problem and now > takes multiple steps per second, whether 5 or 8 or whatever it is, > making the 20 to 30 second quartz accurate to within 10 seconds a year. This is so confused, it's hard to correct each mis-statement. As Peter said, the heart of a quartz watch is the quartz crystal. You are correct that this needs to be cut precisely to get good time control. The quartz crystal typically oscillates at 32,000 times per second. The electrical output of the oscillator is digitally divided down to one pulse per second. This drives a stepper motor that moves the second hand. The minute and hour hands are geared off and moved by the second hand. You are correct that the second hand could be moved more times per second for a smaller distance each time but that this would require more battery power. Watches could also have higher frequency crystals that are more accurate, but this would require more digital division, which would require more power. Craig _______________________________________ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
