The intriguing Sol Invictus watch is the first perpetual mechanical watch, using solar energy. It was born as a result of collaboration between Cabestan and Marc Alfieri.
The complex task of creating this unequaled timepiece was carried out by Marc Alfieri, Jean-Francois Ruchonnet and Eric Coudray, the best specialists in the field of watchmaking. This remarkable model’s name Sol Invictus, translated as Invincible Sun, stems from that of God, revered by the Roman Emperor Aurelian.
The avant-garde watchmaker Marc Alfieri boasts an extensive experience in large scale deployment of solar panels in France. Therefore, while meeting with Jean-Francois Ruchonnet, he came up with the idea of uniting the amazing movement of the Cabestan Winch Tourbillon Vertical and its chain and fusee, drums and vertical tourbillon, as well as a rewinding system supplied by solar energy, at a never-before-seen scale.
Involved in installing the solar panels, which generate 100 megawatts of electricity, Mark Alfieri successfully applied this technology to Sol Invictus with the power produced equal to 100 milliwatts. It became possible due to his cooperation with l’INES, l’Institut National de l’Energie Solaire. This institution has recently created an innovative technique, which allows the production of silicium crystals, utilized afterwards for manufacturing highly efficient solar cells, ideal for small areas and poor light conditions.
The unique Sol Invictus watch incorporates two brushless micromotors. The first is intended for rewinding the movement and the second one is meant for setting the time. Traditionally used in the medical industry, these elements feature the modest dimensions of 1.9 mm x 5.5 mm, diameter and length indicated respectively.
The diminutive controller handles the electrical charge. It governs two micromotors by means of the programmable oscillator and ensures the direction and the speed of the motors. In order to activate or deactivate the motors, there should be used a twin-blade electromechanical contact. It serves to open and close electrical circuit. The entire structure described represents an astounding system for powering the movement.
Marc Alfieri’s partner, Jean-Francois Ruchonnet, has inserted his eye-catching vertical Cabestan movement in the center of the watch. He has also equipped the model with two solar panels located at 12 and 6 o’clock. These important components are mounted in metal frames, secured to pivots.
Underneath the solar cells the watch wearer can admire the micromotors and rechargeable lithium-ion batteries. The twin-blade contact with its glass casing is visible in the middle of the movement. The complicated mechanism, connecting the crown to the movement, also includes a striking 30 mm long axle, traversing the movement in its width.
The heart of this incredible timekeeping instrument is beating inside a powerful case distinguished by elegant curves. Assembled with a single curved sapphire crystal, it features a lateral window at 9 o’clock. Marc Alfieri and Jean-Francois Ruchonnet have also fitted this model with a sapphire case back.
As to Eric Coudray, his assignment was to implement the technologies mentioned and to ensure the excellent performance of the Sol Invictus watch. He developed a special system, automatically detecting when the barillet needs rewinding.
When the power reserve is almost over, a magnet automatically shifts next to the glass tube, which comprises the twin-blade contacts. The magnetic attraction causes closing of the electrical circuit and initiates the rewinding process. Before rewinding the movement, the energy supplied by the motor passes through a number of differential gears. As soon as the rewinding sequence is finished, the magnet moves away and the contact opens for the motor to stop. The second motor is utilized for setting the time electro-mechanically.
The Sol Invictus watch will surely appeal to high-tech audience looking for exclusivity.