Felsa was a Swiss watch movement manufacturer founded in Grenchen in 1918 and becoming part of Ebauches SA in 1928.
Felsa was a relative newcomer to Grenchen, established in 1918 close to the huge A. Schild factory. The company joined A. Schild, Adolphe Michel, FHF, and others under the Ebauches SA banner in 1928.
Felsa became an innovator in the 1930s with designer Friedrich Meyer, who patented an automatic winding mechanism in 1942. A bi-directional winding mechanism was patented in 1947 by Meyer. This was used in the well-known Bidynator movement which was used by Breitling, among other brands. Because of Felsa's successful bi-directional automatic winding system, they were allowed to specialize in automatic movements by the cartel of Swiss movement makers, Ebauches SA, along with ETA and A. Schild.