What is SMD and what can it be used for? For lighting up signs and decorations

For those who are interested and are looking for LED bulbs, I believe that many people would think that the LED that is seen in the market is the same type of LED. But in fact, there are different types of LEDs. But the most commonly used is the SMD LED and because of the advantages of this technology (economic, bright, safe) has caused the expansion of demand. It is rapidly spreading in many industries, especially building decoration, automotive, furniture, billboards , etc.

LED SMD (Surface mount LED), which is a type of LED that is developed from the incandescent LED that we see in electrical appliances in the past. At present, we can still see this type of LED bulbs. Of course, there are many advantages of SMD LEDs, but one thing that makes them stand out is that can be used in a variety of because it can be assembled into a bright panel of various sizes and shapes But the most popular is the strip.

with a line shape can be easily cut flexible appearance and is weather resistant Whether it is outdoor decoration or outdoor advertising signs that are exposed to moisture, sunlight or rain (in the case that we choose to use SMD LEDs, it is designed to be used outdoors. There will be a different protective material than the SMD LED designed for internal use. We should choose to use appropriately for a longer lifespan as well ) we will call this type of SMD LED in many ways, some call it a tablet. Some call it a chip , which has the same meaning. Because the characteristics of the SMD LED are small and have 2 legs that protrude from the body only a little.

SMD LEDs consist of mounting on the circuit board, which we call Surface Mounting Technology (SMT). Semi-Conductor very small This makes installation and fixing the need for specialized tools and skilled technicians to install and fix.

The SMD LED will consume current from 20 mA to 1A and voltage from 2 to 3.6V is now able to light up. very low power consumption Compared to incandescent bulbs 1 to 8 and compared to incandescent bulbs 1 to 4, it can be said that it consumes less current, which is already a highlight of all types of LEDs. And if people who want different colors of light Whether it's red, green, blue, etc., SMD LEDs can meet the needs of users because this type of LED can emit light in different colors. interior work Or decorate the building to shine, it will save beautiful lights without wasting money.

The SMD LED is a type of LED that has little heat build-up This eliminates the need for heat dissipation design so we see that these types of LEDs are used in electronic devices. Electronic devices such as LCD backlighting, keyboard lights, and line LEDs are used in large applications. such as billboards There was no scorching heat at all.

The appearance of the SMD LED is a very small chip. with different shapes according to the model and covered with epoxy resin There are currently 3 numbers in use.

1. SMD3528

This LED is considered to be the first SMD LED to be introduced with a small size. And has a square shape, size 3.5 x 2.8 mm. The brightness of the LED is 5-6 lumens per LED.

2. SMD5050

This LED has been developed from SMD 3528 which has a square shape. But compared to the SMD 5050, it is larger. It measures 5 x 5 mm. and provides 12-14 lumens of brightness per LED.

3. SMD5630

The SMD 5630 is rectangular in shape and measures 5.6 x 3 mm. This LED number is the brightest of the 3 LEDs with 20 – 23 lumens per LED.

Besides these 3 models, we also have different sizes of SMD3030, SMD 3014 and SMD 2835 models, but the above 3 models are commonly used version The most in decorating Decoration and making signs.

How to install and use SMD LEDs

The main point of using SMD LEDs is the power supply because the power and voltage must be related to the load or number of LEDs to be used. Switching power supply (switching power supply) with voltage and current to adjust.

Another thing that is very important in LED protection is a resistor or R (R). The size of this resistor depends on the power supply. The function of the resistor is to filter the voltage from the supply to get the voltage appropriate to the LED connected to it. There is also a way to calculate the value of the path resistor.

R=(Vdc-Vf)/I ohm

Vf = Voltage drop when current flows through it (Forword Valtage:Vf)

I = current required by the LED (Imax)

Vdc = voltage at supply

Let's say that the LED has a voltage drop of 2V and a current flowing through it of 20 mA and a power supply that outputs 5 V of voltage.

R = (5 – 2) / 0.02 = 150 Ohms(Ω) (0.02 in the formula is A, converted from 20mA).

And when we change the supply to 9 V, we put the value in the formula as

R = (9 – 2) / 0.02 = 350 ohms (Ω)

When we change the supply to 12 V, we put the value in the formula as

R = (12 – 2) / 0.02 = 500 ohms (Ω)

With a voltage as low as 12-24 V that is a popular value. Therefore, the use of LED lights to work, decorate or make signs is very safe to use. while achieving outstanding brightness than other light generation technologies.

From the preliminary information mentioned that the selection of SMD LEDs is important for many things besides the design to be beautiful and modern. also the power supply and resistor for us to choose to use correctly as well Usually, the SMD LEDs are already mounted on the circuit board and the resistors are pre-installed. But in some cases there may be a changed power supply. Knowing the formula for calculating resistor values ​​is also helpful.