Yes, Quartz Watches do contain quartz crystals …what a surprise. In this article
I’ll try to explain how it works, and how it interacts with the crystal.
Way back before the crystal watches, you had those fancy wind-up watches.Basic components are of
course an enumerated dial on the face of the watch. A spring to provide the power, which you have to
wind up (dueh). An oscillating mass to provide a time base and tiny gears to slow down the rate of
the oscillating mass, and to connect every piece inside and eventually make the two hands move.
At the end of the ’60s, the oscillating mass was replaced by a transistor oscillator. Of
course the up march of the computer, and it components (a transistor) had its deal in that
evolution.So instead of ticking, the transistor hums at a rate of 100 Hz. That “zooming”
was converted by mechanical components, so it still held some mechanical components.The new watch
was provided with a battery, so no need to wind up your watch every day.
At that time, transistors and circuits were hot and new material. It found its way to the
“time industry”. Very simple explanation for this phenomenon, a computer does nothing
else but counting, and that’s just what a watch needs. So every new circuit or invention in
the computer world was used in every other electronic niche of the market, including watches.
The tuning fork, the component that moves along with the humming transistor wasn’t accurate
enough so scientists had to find something else……the quartz crystal.
It’s around a 1000 times better than a tuning fork. Easily said, but now “all”
they had to do is choose the type of crystal, and the frequency of it. Also, building an integrated
circuit for it wasn’t that easy. You have to keep in mind; the integrated circuits are still
being born.
So what’s so special about the quartz crystal…?
When the quartz crystal is bend in a special way, it produces a certain voltage. Now very
important about this crystal is that no matter what the temperature is, it’ll always keep its
frequency. And on top of that the energy in the crystal before and after it produces its voltage, is
negligible.
Modern quartz watches use a low-frequency bar shaped crystal. Its frequency is about 32 KHz, so
it does 32000 cycles a second.
“If you think that’s alot…your
CPU in your computer is factorized in GHz, so if you have a 2.66 GHz processor, it generates 2 660
000 000 pulses per second …”
The electronics in the watch amplifies the noise at the crystal frequency. This causes
oscillation, the crystal start ringing. The output of the oscillation is converted into pulses
suitable for the integrated circuit. The circuit divides or breaks the frequency further down, and
translates it into a proper format for your display.
