Ever wonders how
the quartz watch got its name? The name has a more literal significance than
you might think. It is actually powered by the quartz crystal, a mineral most
closely resembling the compound of sand and which comes from the Earth’s
continental crust. It is this mineral in minute quantity that has the ability
to keep time more accurately than any other mechanical or automatic watch.
The discovery of
how a quartz
crystal could accurately power a wrist watch changed portable
timekeeping like no other invention. When the first Quartz
Wrist Watch was introduced in the United States in the early 1970s it
was an expensive wrist watch priced at around $500. Not only that, it wasn’t
the most beautiful face ever to adorn a wrist. The LED (light emitting diode)
that showed digital time was bright red, and the technology was only applied to
digital watches. Later, the engineering behind quartz watches was transformed
so the displays could be shown in digital format using LCD (liquid crystal
display) or an hour and minute hand, just like a mechanical watch’s face.
The quartz crystal
of course is at the heart of how a quartz watch works. Quartz crystals have
long worked as transmitters. They were and still are used in transistor radios.
This same theory, in order to be applied to powering a wrist watch, had only a
couple of obstacles to overcome. One was to get the frequency to not give off
too much power. Quartz in a solid form gives off a low voltage of power when it
is bent a specific way. The other obstacle was to create circuit boards, in
miniature, that could regulate the power given off by the crystal and work at
low power.
One of the reasons quartz is such a good material for the job of powering
watches, or any other device, is that quartz, stays in a solid form at even
extremely high temperatures. Because of this, once it is shaped, it will stay
the same shape and therefore give off the same frequency and consistent power.
It is also unchanged by just about any solvent, so it can work well with other
materials needed to manufacture the inner workings of the watch.
Watchmakers soon figured out that a straight bar of quartz or one shaped like a
tuning fork could keep the power going indefinitely. This action is referred to
as the Piezoelectric Effect. When a piece of quartz is cut properly it provides
a starting frequency which then causes oscillation. This translates into pulses
that can be recognized by digital circuits on the circuit board. This then
shows as a display of numbers that change at the exact timing with the
oscillation caused by that perfect frequency. The exact method used in a quartz
watch involves using thin bars of quartz that are plated. Then, using
chemicals, it is etched into the optimum shape. This works just like an
integrated circuit.
There are certainly different quality levels and accuracy levels within the general
category of “quartz watch.” This is because some quartz bars are cut better
than others. The real objective is to have the precise relationship of the
angle cut into the quartz bar correlate with the crystalline axis. Another
major difference has to do with contamination of the components of the watch.
If the quartz bar and circuit are well encapsulated, they are less likely to
get contaminated, which will negatively impact the accuracy of the watch.