Seiko Sport Spring Drive 3days model

One thing to love about Seiko is its initiative to develop accurate watches. A good example is the Seiko Spring Drive movement, which has the qualities of a mechanical calibre but, at the same time, the accuracy of a quartz watch. Find out below what makes this extraordinary movement special.
We want a mechanical watch’s high torque with an electronic watch’s high accuracy. To achieve this perfect combination, Seiko created the Seiko Spring Drive movement — a unique technology conceived by Yoshikazu Akahane in 1977. Seiko even claims that this movement has an accuracy rating of 1 second per day. This movement is used in Seiko’s expensive models like the Credor, Grand Seiko, and Seiko Prospex.
The short answer is that the Seiko Spring Drive gets all the energy from a wound spring. But to expound on that, the mainspring is connected to a gear train that looks a lot like that of a mechanical watch. The difference is that the wheel at the end of the gear train turns continuously in one direction. While in a standard mechanical movement, it turns back and forth. If you’re having a hard time imagining the set-up, the picture above might help.
Another thing to note is Seiko’s genius innovation called the Tri-Synchro regulator, which can control three types of power. These are the mechanical power (mainspring), electric power (IC, quartz oscillator), and electromagnetic power (rotor, stator). The regulator then coordinates these power sources.

As seen above, the Seiko Spring Drive has a quartz oscillator and an integrated circuit but no battery. You might wonder how both of these parts get powered. The power is generated by the rotor and the coil blocks, like how a bicycle dynamo creates electricity from a rotating wheel.

The electricity that we get from the rotor then activates the IC and the quartz oscillator. In particular, the oscillator produces 32,786 Hertz, while the rotor makes 8 turns per second. This electric power then makes the watch’s hands tick. Overall, you can say that the Seiko Spring Drive is a combination of modern and traditional watchmaking techniques.
Accurate and precise. The Spring Drive was made to compete with quartz watches’ accuracy. In particular, it has a rating of +/- 1 second per day, which is twice as accurate as of the most precise superlative chronometer of Rolex. To add, it is significantly more accurate than your average COSC-certified watch.

Long power reserve. Apart from accuracy, the Spring Drive movement also produces a longer power reserve compared to your average mechanical watch. To be specific, it can deliver 72 hours or 3 days of power reserve.

Glide-motion. You might have noticed that the seconds hand of your mechanical watch “jumps” from one second to the next. But the Spring Drive movement makes it glide through the dial. While this doesn’t affect a watch’s timekeeping abilities, it is aesthetically pleasing to many watch enthusiasts.
Expensive. It is no secret that the Seiko Spring Drive is one of the most advanced watch technology. Thus, it takes a lot of time and money for Seiko to produce one. Of course, these factors would translate to the watch’s price tag. The Seiko Spring Drive is proof of Seiko’s excellence when it comes to technology. This useful and efficient movement showed us that a non-battery-operated watch can be almost as accurate as a quartz watch.