Source google image: https://i2.cdscdn.com/pdt2/2/9/4/1/700×700/quattro720294/rw/extel-interphone-video-couleur-2-fils-7-pouces-a.jpg
Schema electrique portier video extel
Source google image: https://i2.cdscdn.com/pdt2/2/9/4/1/700×700/quattro720294/rw/extel-interphone-video-couleur-2-fils-7-pouces-a.jpg