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English
Taste of a Mechanical Watch
＋
High accuracy equivalent to a Quartz Watch
That is the concept of the Spring Drive.
Let’
s start from the drive method of a watch.
The method for driving a watch is divided into two types.
They are mechanical type and quartz type.
In a mechanical watch, the mainspring is wound and its unwinding
power moves the hands.
Amazing mechanism created by high quality workmanship,
and admiration goes to skilled craftsmen with passion.
You can feel the appreciation and personal touch of the craftsmen in
the ticking sound.
On the other hand, with quartz watches, the quartz is oscillated by a
battery and the hands are turned by a motor.
It is characterized by accuracy using state-of-the-art technology.
What is the Spring Drive like?
This is not a mechanical watch or a quartz watch.
In one word, this is a “mechanical watch having accuracy equivalent
to a quartz watch.”
The Spring Drive is a self-contained drive system that realizes
accuracy equivalent to a quartz watch with only the power of the
mainspring and has no battery, motor, or secondary battery.
Accuracy of monthly rate of ±15 seconds (daily rate of ±1 second)
※
equivalent to a quartz watch is achieved while using a mainspring.
The Spring Drive is Seiko’
s proprietary mechanism which is made
available only by SEIKO’s unique combination of skills in both
mechanical and electronic micro-engineering.
Then, how could it be possible to achieve such a degree of
accuracy?
That is explained on the next page.
※ For Cal. 9R15, the average monthly rate is ±10 seconds
(equivalent to daily rate of ±0.5 second).
The power of the mainspring is regulated by electronic
control. That is the essence of the Spring Drive.
What controls the accuracy of a mechanical watch is
the balance spring, a part of the speed-regulating unit, called the
balance.
This part influences the accuracy to some extent
because it is made of metal which expands and contracts with
changes in temperature.
The Spring Drive is
completely different from a mechanical watch in this speed-regulating
unit.
The Spring Drive is powered by a mainspring,
but adopts an electronic speed-regulating unit comprising a
generator, IC circuit, and crystal oscillator.
In a little more detail,
at the end of the train wheel that moves the hands, a series of speed
increasing wheels with a rotor are provided.
The unwinding power of the mainspring rotates the rotor, generating
electricity in the coil to drive the crystal oscillator and IC.
The IC controls the spinning speed of the rotor by applying and
releasing the electromagnetic brake, while comparing the accuracy
of the electric signals generated by the crystal oscillator and the
spinning speed of the rotor.
In addition, by making the energy transfer of the train wheel efficient
and adopting an IC that drives with low power consumption and an
amorphous core with low energy loss for the coil core part, power
reserve of more than 72 hours far exceeding normal mechanical
watches is realized.
An unprecedented drive system which offers quartz accuracy.
This is the Spring Drive.
Spring Drive Mechanism ①
Spring Drive Mechanism ②
