The Breitling Watch Source Forums

OK, this has been bugging me for sometime, so I'm hoping some of the electrical engineering geniuses (genii?) can explain it for me.

Here's my layman's logic. The second hand on a quartz watch advances based on the oscillations of the crystal (caused by passing an electric current across the crystal). Ignoring the thermo-compensation elements of a SQ movement the crystal will vibrate at (usually) 32,768Hz and the hand advances once every 32,768 oscillations. But why?

Why not advance once every 8,192 oscillations - 4 times a second, and effectively become a sweep hand?

I'm sure there's a very good reason, I just need someone to explain it.

From what I have heard (and I am no expert on this), quartz watches CAN "sweep" (Seiko Spring drive and Accutron, for example), but apparently the constant requirement for energy to move the seconds hand in lots of small increments is incredibly draining on battery power. Apparently it is far more efficient for battery powered watches to "pulse" less frequently. All down to prolonging battery life.

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Driver8

Site Moderator

I guess that makes sense, although with modern battery technology you would think that could be addressed.

At least it explains why I couldn't figure out the Hz thing

You know I have wondered about thatm I always assumed that by nature the oscilattions of Quartz crystals that were used to regulate the watches had a certine frequency thus the ticking, whearas mechanical watches had an engineered number of beats per second so in essense mechanical watches do tick but at a much faster rate giving the impresion that they did not.

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Certified watch nut.