Why is the LED lighting industry abuzz with light-emitting diode chips on boards (LED)? What makes these the current favorite? Which applications are these good for and for which ones should these be avoided? Most importantly, what are the factors based on which you should choose the right LED COB chip? These are some questions I have tried to answer here.
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Before we get down to discussing the parameters based on which you should choose your LED chip&#;mainly COB LED&#;let me give you a perspective of the different technologies that power different types of LEDs.
DIP LEDs: Dual inline package (DIP) LED technology, as shown in Fig. 1, is likely what you think of when you picture a LED. It has been around for more than 50 years. Though it is old, DIP LEDs are far from outdated as these are still used extensively for large signs and displays.
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These LEDs are typically found in electronic and electrical gadgets as indicator lights because of their low cost, high brightness, and ease of installation. DIP LEDs generally produce between three lumens and four lumens per LED.
SMD LED chips: SMD or surface-mounted devices or chips (Fig. 2) have become very popular due to their versatility. These are much smaller in comparison to DIP. SMD LEDs have been used to create everything from light bulbs to strip lights.
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SMD chips have the ability to put three diodes on the same chip. When a chip includes a red, green and blue diode, you have a chip that can create any colour you want by adjusting the level of output from each individual diode on the chip. Because these are bright and can change colours, these chips are used extensively for LED strip lights and light bulbs.
COB LEDs: COB chips have multiple diodes (more than three) on the same wafer. This is where the similarities between SMD and COB end. In fact, on every COB chip (Fig. 3) there are multiple diodes.
While SMD requires a circuit for every diode included on the chip, a COB device has only one circuit with two contacts for the entire chip, regardless of the number of diodes. This single-circuit design, regardless of the number of diodes on the chip, leads to design simplicity.
More importantly, LED COB has improved lumen-per-watt ratios in comparison to other LED technologies such as DIP and SMD. Unfortunately, the big drawback of COB (due to single-circuit design) is that multiple channels are necessary to adjust individual levels of light output to create colour-changing effects. Thus, LED COB lighting is powerful and efficient for single-colour applications, but cannot be used to create colour-changing lights.
LED COB chips vary widely in their applications and thus different chips require different wattage, voltage and produce vastly different lumen counts. However, LED COB chips have good lumens per watt ratio, starting typically from 80 lumens per watt minimum and going up to 100 lumens per watt or more. This attribute of high efficiency makes these a clear favourite for all applications running on batteries, including mobile phones, cameras and more.
MCOB LEDs: A variant of COB is now gaining popularity&#;MCOB or multiple chip on board. MCOB devices (Fig. 4) are very similar to COB chips in their application and are essentially multiple COB chips together in series. MCOB devices produce a lot of light and are even better than COBs for low-wattage applications. MCOB is a very new technology at this point that not many manufacturers are producing, but will likely catch on.
From the above, it is clear that COBs are one of the best options available. These promise to lower the overall cost of LED luminaires by providing several benefits, such as greater design flexibility, better light distribution and simpler manufacturing process. Here is why:
1. COBs produce less heat as compared to other forms of LEDs. This, in turn, results in higher efficiency. Better thermal dissipation is achieved because the LEDs are directly mounted on an aluminium sheet, which, in turn, offers better heat dissipation as compared to other materials.
2. COBs have a lower failure rate because spot soldering is no longer required as it is built directly onto the PCB.
3. Another major factor is that, typically COBs have a much wider beam angle and thereby a higher colour rendering index (CRI). This makes these a preferred choice for outdoor lighting luminaries such as streetlights.
4. It is also possible for COB LED package to be assembled in the heat sink directly. In such a scenario, a separate mounting and PCB are not required.
Let us now discuss some of the parameters that are important while choosing COB LEDs:
Forward voltage: This is the amount of volts the LED requires to conduct electricity and light up. A typical 20-watt COB LED would require a forward voltage of about 29V DC to 32V DC.
Forward current: It is the current flowing through an LED when forward voltage is applied to it. A typical 20-watt COB LED draws about 640mA. Therefore you should choose the appropriate current driver as per the rating on the LED package.
Power consumption: An LED lamp packaging may be specified with power consumption in watts, lumen output, colour temperature, operating temperature range and others. Power rating in LED lamps should not be confused with power ratings in other lighting systems. With less wattage rating in LED lamps, as compared to other lighting products, you can get more light output or lumen output as shown in the table on the previous page.
Luminous flux: It is used as an objective measure of the total amount of visible light that your lighting source produces. The SI unit of luminous flux is lumen (lm). If you compare a CFL and a normal white LED, the latter is highly energy efficient and uses very little energy.
The lumens produced by an LED bulb as compared to other lighting sources are shown in the table. COB LED offers a greatly improved lumen-per-watt ratio compared to other LED technologies.
Efficacy: This parameter is for deciding the performance of the LED. It is the effectiveness of the LED at converting electricity into visible light. Thus, efficacy is total lumens per watt. For example, if a nine-watt light bulb comes with lumens of 800, it means it has an efficacy of about 90 lumens per watt.
CRI, or colour rendering index. CRI is a measure of light quality, showing how well a light source replicates colour to the human eye. White light is made up of all the colours in the light spectrum. We can see the colour of every material object in daylight. Natural daylight has the highest CRI rating, while artificial light sources cannot produce all the colours of the light spectrum. CRI of 80 is the standard requirement for general home use.
CCT, or correlated colour temperature: CCT is measured in Kelvin (K) to refer to the warmth or coolness of the white light that the LED produces. The higher the temperature, the cooler the light looks. An LED bulb marked with K does not actually heat up to °F, but still gives off a warm light.
Some LED bulbs have more than K CCT, which makes the light more towards bluish rather than white. A warm light is around K, while neutral white at around K and cool white at K or more.
Lifespan of LED COB: Another important specification is the lifespan in hours. Some LED lamps may last for 50,000 hours. So if you consider daily use of eight hours, it may last 17 years.
Life of the LED also depends on the heat-sink used. COB technology gives the best conditions for optimal cooling, which, in turn, increases efficiency and lengthens the overall life of the lamp.
Beam angle: Beam angle of a bulb refers to the spread of light to your surroundings. For example, a spotlight in a kitchen will have a beam angle of between 35 degrees and 60 degrees. Standard and candle-shape bulbs require a beam angle as wide as possible when fitted to lamps. Though, ideally the beam angle should be over 200 degrees.
To distribute light better, to more areas, you would need a wider beam angle. But a narrow beam angle is required when you want to have the light more focused and intense. Adjusting beam angles correctly can vastly improve the lighting effect in a room.
Contact us to discuss your requirements of LED COB Vs SMD Vs Cree. Our experienced sales team can help you identify the options that best suit your needs.
Junction temperature: It is the highest operating temperature of the actual semiconductor in an electronic device. This temperature is normally specified in the datasheet. You will require this value when calculating the case-to-ambient thermal resistance for a given power dissipation. This will help you select an appropriate heat-sink.
Many publicly available industry reports claim that there is an increasing demand for COB LEDs in the global lighting industry. As of now, you can see LED COB in many consumer and industrial products including bulbs, downlights, tube lights, street lamps, bay lights and others. One can confidently state that their future looks bright, for now.
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Sani Theo is senior assistant editor &#; tech at EFY
Introducing COB LED lights from HitLights. The newest innovation in LED strip lights are now available from your most helpful LED lighting company, HitLights. If you want to know what COB lights are; how are COB strips different from standard LED strip lights; are COB strips eco-friendly; what does COB mean in LED; or when you should use COB strip lights then you are in the right place. By the end of this post, you&#;re going to have all your HitLights COB know-how set!
What is the meaning of COB light?
COB stands for chip on board. To the average person (even most LED fans) this won&#;t explain the COB difference. COB lights are a type of LED strip lights that appear to be one continuous, smooth light source, and the strip emits an alluring glow. The diodes of COB strips are tightly packed together along the strip, and covered with a phosphor coating which gives the COB strip its glow when lit. The COB lights can have a greater light output than standard LED lights, but otherwise share a lot of the benefits boasted by traditional LED strip lights. (Like being cuttable; energy saving; install with double sided tape.)
To give you a mental picture of the visual difference between traditional LED strip lights and COB strips, standard LED strips have a &#;polka dot&#; effect where you can see each diode as a separate light source (the dots.) Thanks to the phosphor coating, COB lights appear the way a glow stick looks: a long, luminous smooth glow where you can&#;t see the individual diodes of the COB unless it&#;s dimmed to one of the strip&#;s lowest output levels.
Have you ever seen people place diffusers on top of traditional LED strip lights to eliminate the dot look? COB lights have no need for a diffuser because they have a radiant aura already built in.
Let&#;s talk chips for a sec. What is the chip that is referred to in the name chip on board? The diodes of LED light strips use semiconductor chips&#;this is where the electrical current turns into light (in broad layperson terms.) HitLights COB strip lights use what are known as flip chips&#;a relatively new way to position the semiconductor chips to dissipate heat more efficiently. COB lights are able to pack more diodes into each inch of strip thanks to innovations in chips and placement. More on COB advantages in a moment.
Finally, to close out the basics on what COB lights are, we must address what we know you&#;re thinking. We didn&#;t come up with the name &#;COB&#; but that&#;s the name that has stuck in the industry. And when folks talk about these lights it&#;s &#;cob&#; (like corn on the cob; not cee-oh-bee. Who knows? Maybe we can have an LED influencer get a cool new name like LED SuperGlow to stick. We&#;ll let you know if that happens, but until then&#; back to business.)
What is the difference between COB and LED lights?
COB lights are a type of LED light, but with smaller diodes, installed closer together on the strip material, covered with a phosphor coating, appearing as one continuous glowing light when illuminated. COB lights are the latest innovation in LED lighting, which in themselves are an innovation from incandescent lights. Since COB lights are a development based off of LED technology, there are obviously many similarities. But there are also some notable differences, including appearance and style of light output, elimination of &#;hot spots,&#; and overall brightness.
Let&#;s go a little deeper into some of the differences.
Energy Usage
Attention eco-friendly improvers! If you like to use greener options in your home, office, or business, you can use COB strips and go green, too. HitLights 24 volt COB strip lights are efficient to the tune of 100-110 lumens per watt. We know lots of people come to LEDs for the energy savings, Now you have even more options&#;like the HitLights COB light strip&#;without giving up energy efficiency.
Appearance & Style
Smooth, luminous, glowing, continuous&#;that&#;s COB. No spots or dots, just a powerful, uninterrupted glow from the start of the strip, right to the end. If you thought LED strip lights were a pioneering product, COB strips are the next step. Advance the look of your lighting installations with COB.
Lifespan
You&#;ve heard the phrase, &#;for a lifetime.&#; Well get ready to enjoy HitLights COB strips for a whopping 50,000 hours! If that makes you raise an eyebrow, you can rest assured with HitLights&#; better than industry standard 6-year warranty. We believe in our products (manufactured in our own facilities to our rigorous standard) and stand behind every strip we offer.
Other Tech Specs
Regular LED strip lights have a beam angle of about 140 degrees (the beam angle is the surface of the diode emitting light.) COB lights have a beam angle of a full 180 degrees&#;this in part is why the COB lights are visibly brighter. We already mentioned just how many more diodes are on COB lights than standard LEDs. How many? HitLights COB light strips offer 155 LEDs per foot. That&#;s a lot of diodes getting their glow on!
How are COB strips and traditional LED lights similar? COB lights possess all of the benefits of all the other LED strip lighting you love. Both COB and LED strip lights are flexible, easy to use and install, and provide clear, attractive light in applications that other lights can&#;t match. COBs are cuttable&#;even with that continuous flow of light that seems to be unbroken, COBs can be snipped along regular intervals on the strip. Simply look for the cut line and use simple scissors to get your COB strip to your desired length. Can COBs dim? Yes! Just like most other LED lights, COB lights are dimmable (HitLights can supply you with one of the best dimmable drivers in the industry.) For those of you who are drawn to LEDs for their green properties, COBs keep on with that tradition, being eco-friendly, too.
When it comes to the COB strip light offered by HitLights, you&#;ll be able to choose from a warm or cool white on our bright, full of light strip (with an impressive output 360-390 Lumens per foot.) HitLight&#;s COB strip light uses top of the line mounting tape, featuring genuine 3M double sided tape to install the lights. Shop for HitLights 16.4 ft COB strip light now, in warm white or cool white, 24 volts.
Are COB lights any good?
COB lights are pushing the innovation of LED strip lights to new, better heights. Where are some of the places you might use COB lights instead of traditional LED strip lights? Our first suggestion is to try COB lights where the actual strip will be visible (like lining a window frame or exposed on ceiling molding.) You won&#;t need a special cover for the strips and you&#;ll love the contemporary ambiance that emanates from the COB strips.
If you want a full lighting option, since the light output is so prominent in COB strips, COB might be your choice if you want full room lights where brightness is an asset.
Do you want to put style to the forefront? If you are trying to create a certain cool, modern, or high-style look with your lighting, COB works in these applications, too. Lighting with an aura like COB radiates creates a look and feel that is of the moment, and maybe even a little futuristic.
You don&#;t have to wing it with any of our lights or products&#;including our new HitLights COB strips in either warm white or cool white. One of our team members is ready to answer any of your specific COB questions. We&#;re ready to help you plan and achieve all of your COB home improvement projects. Our tech team is ready to talk you through any application of our products.
If you are looking for a COB lighting supplier or custom COB lighting to serve your needs, our PRO team wants to talk to you. Learn more about our PRO Accounts at HitLights and if PRO is right for you and your business.
COB strip lights are a wonderful option for home use or in your business or commercial locations. We are excited for the future of LED lighting, and our new line of COB lights are a key element of that future. If you are intrigued by the look or performance of COB strip lights, we encourage you to try one today and we know you will love them as much as we do.
If you&#;re ready to glow up, get that COB going&#;call us today. We would love to hear about how you are using these new COB lights. Questions? Call us now at 1 (855) 768-. to get the assistance you need. HitLights is ready for COB or any LED projects you have. Ready, set, glow!