LED – Light Emitting Diode - LEDs for Beginners in Electronics An LED must be connected in a circuit the right way around – observe the polarity of the LED. The way that the schematic symbol of the LED maps to the physical LED is shown in the diagram below: On the physical LED, the longer lead (or leg) of the LED is the anode. Light Sensing with an LED Schematic Circuit Diagram Home LCD-LED Display Light Sensing with an LED Schematic Circuit Diagram. Light Sensing with an LED Schematic Circuit Diagram. on: August 19, 2019 In: LCD-LED Display, Lights and Display Board Circuits No Comments. Print Email. Many robotic applications require a sen-sor to measure light levels. LED circuit - Wikipedia OverviewBasic circuitPower source considerationsMOSFET driversSeries resistorLED arraysIn electronics, an LED circuit or LED driver is an electrical circuit used to power a light-emitting diode. The circuit must provide sufficient current supply to light the LED at the required brightness, but must limit the current to prevent damaging the LED. The voltage drop across an LED is approximately constant over a wide range of operating current; therefore, a small increase in applied voltage greatly increases the current. Very simple circuits are used for low-power indicator LEDs. MoreSee more on enpedia · Text under CC-BY-SA license LED projects and circuits - Electroschematics Interesting LED projects and circuits and from various domains including Arduino LED projects. Have fun! Interesting LED projects and circuits and from various domains including Arduino LED projects. Have fun! X. Top 10 Articles. TM1638 – First Light T.K. Hareendran - 01/14/20.