Application Expansion This simple non-contact test pen can be used in many applications such as cables, wires, sockets, switch boards, junction boxes, circuit breakers, etc. Since it is battery powered, the entire circuit can be packed into a small box; this makes it portable and safe. In addition to home use, this project can also be used in various fields such as security, communications, and the environment. In use, if the LED does not go out after the power measurement is completed, the 220 ohm resistance can be increased until it goes out.
