Credit to thewatchbox.com for this quick breakdown on the spring drive technology:
"How does the Spring Drive work? What makes it different from a normal mechanical watch? To simplify the answer to the questions, the Spring Drive is an automatic movement but with the escapement replaced by a
Tri-synchro regulator... Acting as a control to manage the speed [at which] the mainspring unwinds, the Tri-synchro regulator is comprised of an Integrated Circuit (IC), electronic brake, and quartz crystal. It uses three types of energy to regulate speed:
- Mechanical power from the mainspring
- Electrical power from an IC/quartz oscillator
- Electromagnetic power to apply a brake through a rotor
The Tri-synchro regulator also allows for a longer-lasting power reserve of 72-hours, even if the chronograph is running. It works at the end of the gear train with a glide wheel and uses electromagnets to slow the energy without friction. In contrast, a normal escapement starts and stops. The integrated circuit has the ability to sense if the glide wheel is moving too fast and will slow it down as needed."