Source google image: http://4.bp.blogspot.com/-dGdKb0X3PZc/UdmLGrg72qI/AAAAAAAAIGY/nvd-EREwNh8/s1600/Sch%C3%A9ma+d%C3%A9velopp%C3%A9+avec+contacts+de+position+%C3%A0+ouverture+Commande+%C3%A0+Tr%C3%A8s+Basse+.JPG
Schema electrique d’une sonnerie
Source google image: http://4.bp.blogspot.com/-dGdKb0X3PZc/UdmLGrg72qI/AAAAAAAAIGY/nvd-EREwNh8/s1600/Sch%C3%A9ma+d%C3%A9velopp%C3%A9+avec+contacts+de+position+%C3%A0+ouverture+Commande+%C3%A0+Tr%C3%A8s+Basse+.JPG