A Light-Emitting Diode essentially is a P-N junction solid-state semiconductor diode that produces light when a current is applied although device.  By medical definition, this is a solid-state device that control buttons current without the deficiency of having heated filaments. How does a LED work? White LEDs normally need 3. 6 Volts of Direct Current (DC) and use approximately 30 milliamps (mA) of current and has a electricity dissipation of approximately 100 milliwatts..