How do I identify LED terminals in the same way? Touch each probe to one of the LED terminals and turn the multimeter to the diode setting (which is usually indicated by a diode symbol).

The cathode has a flat area on the rim of the LED body, as shown in the diagram. The anode is the longer lead (or leg) on a physical LED. Which way do you connect an LED? The polarity of an LED must be observed in a circuit the right way around. The negative cathode pin will be the pin closest to the flat edge.Īside from that, which side of an LED is the positive side? The LED’s positive side, known as anode, is represented by the longer leg, while the shorter leg, known as the “cathode,” represents the negative side. Try finding the flat edge on the LED’s outer casing if someone has trimmed the legs. You can try to locate the longer leg, which should indicate a positive anode pin.