I am just getting back into the electronic field after 15yrs out of college. (So I just have a general concept for now.) My 10 year old son and I would like to build a circuit to locate a lost remote for his project. We have looked at a few key finders but they were clappers basically. We don't want to reinvent the wheel so if any body has any old diagrams or ideas please feel free to share. Thanks in advance!!