Resonance is a sophisticated and demanding horological technique that has rarely been attempted, let alone mastered.
One body in motion relays its vibrations to its surroundings. When another body with a similar natural resonant frequency to the first receives these vibrations, it will absorb energy from the first and start vibrating at the same frequency in a sympathetic manner. The first body acts as the “exciter,” while the second acts as the “resonator.”
The resonant Caliber ARF15 is a classically constructed manually wound movement that was conceived, manufactured, assembled, and regulated in-house. It beats at a 3.5 Hertz (25,200 vph) frequency, allowing the observer to really appreciate the patented, resonant regulators in action. The movement is resolutely modern, with a novel, yet impeccably executed finish providing a roomy and stable stage for the real show: the symmetrical twin display of seconds, which are bound by a single spring.
The resonance clutch spring needed to realize the Mirrored Force Resonance’s twin display of seconds was so technical that the brand’s team, under the direction of technical director Claude Greisler, was left with no choice other than to create what it needed in house. Like Calibre ARF15, the resonance clutch spring comprises only a traditional horological material: steel. Greisler and his team spent fully two and a half years perfecting the shape and characteristics of the spring: calculating, optimizing, simulating, testing, and improving again and again until the spring had the optimal, unique form needed to connect ARMIN STROM’s two sets of oscillators, each comprising twin balance wheels and balance springs.
Since the two connected oscillators make their revolutions in opposite directions, which is eminently visible on the dial side of the watch, one rotating clockwise and the other counterclockwise, the animated elements look much like they are performing a magic trick. If the 48-hour power reserve has been exhausted and the movement requires a fresh injection of energy through winding, the twin balance wheels need approximately 10 minutes to become synchronous. In case of any outside influence in the form of shock, it takes only a few minutes for the two balances to find their resonant rhythm once again.
This is because it is not the balance wheels that Armin Strom’s technical team has connected using the resonance clutch spring, but rather the balance spring studs, which receive the impulses.
The case band pusher at 2 o’clock resets the luminous twin seconds’ displays to zero, simultaneously resetting the twin balance wheels. The Mirrored Force Resonance is the most complicated timepiece that Armin Strom manufactures; it is not surprising that a patent has been registered on it.