Source google image: https://www.installation-renovation-electrique.com/images/schemas%20de%20principe/schema%20de%20principe%20double%20allumage.jpg
Schema electrique interrupteur 2 direction
Source google image: https://www.installation-renovation-electrique.com/images/schemas%20de%20principe/schema%20de%20principe%20double%20allumage.jpg