How to distinguish the positive and negative poles of LED SMD lamp? In what areas?

The positive and negative poles of light emitting diodes are fixed no matter what color. Direct-entry LED: long legs are positive electrodes and short legs are negative electrodes. You can also carefully observe the electrodes in the tube, the smaller one is the positive electrode, and the larger one is the negative electrode similar to a bowl. SMD diode: Seen from above, one side with colored lines is the negative electrode and the other side is the positive electrode. It can also be measured with an ohmmeter of a multimeter. For dial multimeter, set it to "Ohm x 1". When the diode emits light, the red stylus is connected to the anode of the SMD LED, and the black stylus is connected to the cathode of the SMD LED. Because the LED turn-on threshold is about1.5-1.8V. It is possible that the voltage provided by the digital multimeter cannot start it. So look at this sign. SMD light emitting diode (SMD LED), the green dot is the negative electrode, and the opposite is the positive electrode. Usage: SMD LED is mainly used in lighting system, decoration, indicator light of electronic equipment, backlight, display and equipment. In 2009, the decline in the output of mobile phones and LCD TVs may affect the supply expectation of such components. LED SMD lamp is made of FPC circuit board, LED lamp and high-quality silicone sleeve. Good waterproof performance, safe and convenient use of low-voltage DC power supply, diverse and bright colors; Outdoor use can resist ultraviolet aging, yellowing and high temperature. This product is widely used in building outline lights, quasi-decorative lighting in entertainment places, advertising decorative lighting and other fields. Jewelry display cabinet lighting, display cabinet lighting, cabinet lighting, wardrobe lighting, store decoration lighting, lighting art lighting, advertising light box lighting, hotel, guesthouse, home villa decoration lighting can be bent at will, and can be fixed on concave and convex surfaces at will, forming a small and colorful loop. High brightness, adjustable lighting angle, and the installation and length can be customized as required. Energy saving: constant current drive, ultra-low power consumption, electro-optical power close to 100%. Environmental protection: no ultraviolet and infrared radiation, no heat and no danger of mercury leakage.