Abstract: A light for use in a string of lights has a lamp and a light socket that may include a parallel group device that may perform a variety of functions. One of those functions is to serve as a resistive element to regulate voltage and current to keep other lights in a group of lights arranged to be electrically in parallel lighted to the same intensity in the event one of the lights burns out or is removed. Another function of the parallel group device is to control the lamp in the socket so that it lights and goes out on command. The socket is designed to be closed against moisture and to be easily manufactured by hand or by machine. It includes piercing terminals that, when pressed into the electrical wires that run from light to light in the string, allow electrical connection with the lamp leads and the parallel group device leads.

Abstract: A plug is diclosed that is adapted to be inserted into a standard electrical outlet and has a built-in integrated circuit for rectifying the alternating current received from the outlet and limiting the direct current produced. The plug is specifically suited for low-current, low-voltage applications such as supplying DC to a string of ornamental lights. The integrated circuit has a diode with a modified cathode that acts as a fuse as it is rectifying the alternating current. The cathode is formed of a plurality of electrically parallel conductors. Excessive current blows out at least some of these conductors in the same way a conventional fuse blows. Various embodiments add other current-limiting elements, elements for producing full wave or near full wave rectification, and for opening the circuit when they detect extraneous currents.