Hi 2 All I need an idea for a friend for his cooling system. the problem is if the fan is stopped or stuck or have any malfunction, he want to cut the power to the system immediately. now, I though about measuring the fan wind or measure the fan current. which method is the best way? do you have any simple idea or a cheap one? Thanks Tal -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics