1. Look at the pins

The lead of the LED is generally longer for the positive electrode and shorter for the negative electrode.

 

2. Look at the logo

Some SMD light emitting diodes packaged in packages such as 0805 and 0603 will have a "T" shape or inverted triangle symbol at the bottom, with one side of the "T" being the positive electrode and the other side being the negative electrode; The "side" of the triangle symbol is close to the positive electrode, and the "corner" is close to the negative electrode.

 

3. Look at the missing corner

In the LED energy-saving lighting industry, 5050 chip LEDs are often used. This type of chip LED is square, with a small gap at one of the four right angles. The end with the small gap is the negative electrode, and the other end is the positive electrode.

 

4. Watching the shape of the body

Observe the shape of the two outgoing lines in the tube from the side. The small one is the positive electrode, and the large one is the negative electrode.

 

5. Pass the multimeter test

Set the multimeter to the "ohm x1" position. When the diode emits light, the red lead connects to the positive end of the SMD LED and the black lead connects to the negative end of the SMD LED.

 

There are many ways to look at LED patch lamp beads, and you can choose the judgment method that suits you. If you don‘t know, you can also consult professional manufacturers, such as Shenzhen Tengjie Optoelectronic Technology Co., Ltd., which is a high-tech enterprise specializing in the research, development, manufacturing, and sales of LED light sources, mainly engaged in LED single core piranha, multi core piranha lamp beads, LED patch lamp beads, LED plug-in lamp beads, LED high-power lamp beads LED integrated high-power, COB light source, LED infrared tube, LED sterilization lamp, LED receiver and emission lamp, and other photoelectric products.