> I have a IR-sensor with an open collector output. > Can somebody be kind and explain how it works > or show me with a drawing will be nice! Do you realy expect a response without providing the type number? Did you check the datasheet? Wouter van Ooijen -- ------------------------------------------- Van Ooijen Technische Informatica: www.voti.nl consultancy, development, PICmicro products docent Hogeschool van Utrecht: www.voti.nl/hvu -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist