LED lights have been around for some time now, but have you ever taken the time to truly understand why they dominate the world of light in today’s age? These small marvels of science are allowing us to carry powerful and light weight, as well as durable and resilient, light sources easily on our bodies or devices we use daily (phones).
They have developed exponentially over the last few years allowing most of the population to find a use for LEDs as they have become cheap, reliable, and widely available. This post will take a complex topic and sum it up nicely for anyone looking to quickly gather some knowledge on the vast world of LED lighting technology.
The types of LED lights available are as follow:
- Flat Top
- Round Top
- COB
- MCOB
- DIP
- SMD
- FLIP CHIP
What Is An LED? How Does An LED Make Light?
LED lights have been around for some time now, but have you ever taken the time to truly understand why they dominate the world of light in today’s age? These small marvels of science are allowing us to carry powerful and light weight, as well as durable and resilient, light sources easily on our bodies or devices we use daily (phones). They have developed exponentially over the last few years allowing most of the population to find a use for LEDs as they have become cheap, reliable, and widely available. This post will take a complex topic and sum it up nicely for anyone looking to quickly gather some knowledge on the vast world of LED lighting technology. Before we begin discussing the actual LED, however, we have to understand how light is even created.
The diagram for a diode is simple. It looks like this…
The cathode, as seen by the images, is the negative side of the diode. If you have an individual LED, you can tell which is the cathode by looking at the wires coming out of it or the top of the LED. The side that is shaved flat will be negative as well as the wire that is shortest. In the scientific diagram you can tell which side is the cathode by seeing which side has the – or +. The symbol’s arrow points against the direction of flow because the schematics created by engineers show current flowing from positive (+) to negative (-). This diode, which allows current flow, is known as forward-biased.
If you want more information on diodes you should learn about the following:
Forward Voltage
Forward Current
Polarity
We will not discuss these as our goal is to keep things simple. Now that you have a basic understand of the way an LED makes light and how the science works we can discuss the different types or technologies of LEDs. First we will discuss color.
How LEDs Produce Different Colors
LEDs produce different color by using different materials which produce photons at different wavelengths. LEDs use materials that can handle the necessary levels of electricity, heat, and humidity. High-brightness red and amber LEDs use the aluminum indium gallium phosphide (AlInGaP) material system. Blue, green and cyan LEDs use the indium gallium nitride (InGaN) system.
Together, AlInGaP and InGaN cover almost the entire light spectrum, with a gap at green-yellow and yellow. One method of achieving a larger spectrum of colors is to mix different colors of LEDs in the same device
Combining red, green, and blue LEDs in a single LED device, such as a lighting fixture or multi-chip LED, and controlling their relative intensities can produce millions of colors. Additionally, combining red, green, and blue in equal amounts produces white light.
Why do Lumens Matter?
Lumens VS Watts VS Lux VS Candela
Lumens are currently the most common measurement for light sources. Learning about headlamps or flashlights, or any light for that matter, nowadays is like researching a paper for school in that you have to learn all kinds of confusing information and hopefully understand it well enough to explain it simply. Today is your lucky day. In a few minutes you will understand what each term means and how it applies to your uses or needs when it comes to light.
Lumens (lm)
Lumens simply describes how much light is produced by a light source. A lumen is a measurement of luminous flux which is the amount of visible light.
Think of lumens as how much light is given off by the source.
Lux (lx)
Lux is a unit of measurement for a specific area. 1 lux equals 1 lumen per 1 square meter. Simply put the lux measurement is how bright an area will be.
Think of Lux as how bright a specific area will be.
Watts (Wattage)
Watts are units of power consumption. They are not accurate in today’s age when it comes to measuring how bright a light source is because an LED can consume way less watts than a halogen bulb and be many times brighter. Watts can, however, give you an idea of how quickly your battery will drain.
Think of Watts as how much energy is required to power a light source.
Candela (cd)
Candela, also called candlepower, is the measurement for the luminous intensity. Candela describes how far one can see the light from the source. Laser pointers have the highest levels of candela because they can be seen from super far distances whereas, for example, a street light might only be seen from a block away.
Think of Candela as how far away you can see the light from the source.
Now we are only about halfway done here, and the knowledge is slowly seeping into your brain. You might be able to know what you’re looking for, but what shape or housing will your desired LED come in? There is a variety of LED types including Surface Mounted Device (SMD), Chip On Board (COB), and Direct In-Line Package (DIP) LEDs. To add to the confusion, you can also get round top and flat top LEDs which are made for spot beams and flood beams, respectively. A flood beam will disperse the light and make it “softer” but it will cover a wider area. A spot beam will go farther but will mostly light the area where you are pointing the device.
The Flat Top LED
The Round Top LED
LED Technologies
COB LED
Chip On Board LEDs offer many advantages over other options. COB LEDs are basically multiple LED chips (Typically 9 or more) bonded directly to a substrate by the manufacturer to form a single module. Since the individual LEDs used in a COB are chips and not traditionally packaged, the chips can be mounted such that they take up less space and the highest potential of the LED chips can be obtained. When the COB LED package is energized, it appears more like a lighting panel than multiple individual lights as would be the case when using several SMD LEDs mounted closely together.
MCOB LED
Since the creation of COB chips, a variant has come along called MCOB or “Multiple Chip On Board”. MCOB devices are very similar to COB chips in their application and are more or less just multiple COB chips together in series. Light emitted by MCOB devices depends on how many COBs are connected in series.
DIP LED
This module is put together by using three bubble shaped color LED bulbs that are joined with two connector feet. Sockets or through-hole soldering is used to mound these DIP modules. With sockets, replacing the device is very simple and there is no risk of damage caused by overheating (which occurs during soldering). After the assembling of DIP outdoor modules is done, heat-dissipating silicone is used to weatherproof each module.
SMD LED
Surface Mounted Device is an LED chip fused to a Printed Circuit Board (PCB) that can be integrated into various packages such as light bulbs, string lights, LED strips, downlights and even the notification lights on phones.
Flip Chip
LED assembly is basically flipped over and faces downward. This technology uses the surface area of the flip chip for connection instead of using wires. The flip chip allows for less inductance as it does not use wires. The main benefits of this technology include all connections being made simultaneously and the top surface allows for greater heat dissipation.
What now? Still feel confused? We could go on and on about the different uses for all of the technologies, but in the end you are the only one who can choose the best one for your needs. One of the most important choices you can make is getting a light has a flood or spot beam. COB LEDs, by design, will often have a flood beam so if you need your light source to light up an area far away you might want to choose something else like an SMD LED. If you ever wondered what the red light is for on a headlamp or flashlight read our post here. If you have been looking for a military headlamp we also have a post that might help you decide, or at least learn about, what a “military” headlamp is; you might be surprised, but read it here