NOTE: I took this picture myself from my camera, Please Do not mind for image clarity ,so i have put some labellings also. If the positive lead touches the anode and negative touches the cathode, the LED.

On appelle Г©tymologie la recherche de lorigine des mots et leurs changements structuraux et de signification. From Greek anodos a way up, from hodos a way alluding to the movement of the current to or from the positive pole. The main difference between anode and cathode is that, in general, anode is the terminal where the (conventional) current flows into a device from outside, whereas cathode is the terminal where (conventional) current flows out of the device. The polarity of a tiny, yellow, surface-mount LED is tested with a multimeter. Signification de 'anode' dans le dictionnaire anglais. The larger end inside the led is -ve and the shorter one is +ve, that is how we find out the polarity of a LED They have four leads, one for each color of red, green, and blue and the fourth is a shared terminal of the three diodes inside known as either common cathode. The terms cathode and anode are used to refer to terminals of a polarised electrical device. An EPA may be adequately protected by ESD controls as outlined in ANSI/ESD S6.1. As they have to be crystall clear to glow so they donвЂ™t have any labeling on it, so the only way to know is either to test it with a multimeter or by carefully observing inside the led. LED Engin recommends taking reasonable precautions towards possible ESD damages and handling the LZ4-00A108 in an electrostatic protected area (EPA). Notice the picture carefully and compare it with the LED diode symbol, that should tell which one is вЂ“ve and +ve terminal. Finally, in between the anode and cathode are two layers made from organic molecules called the emissive layer (where the light is produced, which is next to the cathode) and the conductive layer (next to the anode). I hope the figure below can solve this problem of identification. In between those layers, theres a negative terminal (sometimes called the cathode) and a positive terminal (called the anode). LED's or Light Emitting Diode's donвЂ™t come with any labeling on it to identify Cathode(-ve,GND) or Anode(+ve). This is an electronic display device which. Common anode is used in the seven-segment displays. Since current flow is in the opposite direction of the electron flow, we see it as current flowing into anode. In particular, the difference in chemical potential between the anode ( A) and the cathode ( C) is termed as the working voltage, also known as the open circuit voltage, VOC 31, 47: (1) V O C ( ) A C e where e is the magnitude of the electronic charge. Because of this, electrons flow to cathode from the anode. Sometime the diode symbol creates confusion too.Identifing a LED's the cathode and anode of a led is very easy by looking inside. Therefore, there is electron abundance on the anode compared to the cathode.

So for identification, ledвЂ™s comes with a unique way to identify its terminals as Anode or Cathode. While referring to any schematic involving led's we sometimes get confused with the identification of the terminals.

Led anode vs cathode