LED sign is a type of semiconductor diode that emits light through photoluminescence. Like ordinary diodes, LED sign allows an electric current to flow in only one direction, because of its p-n junction. When electrons flow into this junction their energy state changes, and LED sign give off photons, or light.
While normal LED signs are designed to work with currents in the tens of mA, high power LED sign can be used at over an ampere. For LED signs two types of LED sign panels are used: The conventional LED sign panel which uses discrete or separate LED signs; and the surface-mounted device LED sign panel.
