Lumistrips LED Lighting Blog

Understanding and Measuring the Lifetime of LED Lighting versus Incandescent Bulbs

Understanding and Measuring the Lifetime of LED Lighting versus Incandescent Bulbs

Product lifetime, Light Bulb vs LED

The typical product lifetime of an incandescent light bulb is 1000 hours. When the bulb reaches the end of its product lifetime, it cannot emit light anymore. Typically, just before, there is spark or pop, as the filament inside breaks down.

LEDs use a different meaning for product life. They are the only light sources that over time lose brightness, even up to 90% of initial flux. Eventually, LEDs will also fail completely. However, some emit visible light even after decades.

For example, a Nichia LED with 60,000 hours typical product lifetime will continue to light well beyond the 60,000 hours rated life. Under normal operating conditions, it will even after 200,000 hours.

LED lifetime is the time interval the product can still serve its intended purpose.  The time passed until a LED has 70% of the initial brightness is equal with the product life, L70 lifetime.

For all reputable lighting manufacturers and sellers, LED lifetime is equal with L70 lifetime. At this point, the LED is considered end-of-life and has to be replaced.

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SunLike LEDs: A Revolution in Natural Spectrum Lighting

Seoul Semiconductor's groundbreaking SunLike LEDs are natural spectrum LEDs that boast a high color rendering index (CRI) of 98+

SunLike LED techology from Seoul Semiconductor and Toshiba

The innovative SunLike LEDs from Seoul Semiconductor are the first natural spectrum LEDs on the global market. For the first time an LED can emit light that closely matches the spectrum of natural sunlight.

SunLike LED package design


The special ability to have a spectrum close to sunlight comes from using a new LED design, with a purple emitter in combination with a red, green, and blue (RGB) phosphor mix, unlike conventional white LED that use a blue emitter and yellow phosphor.  By removing the blue LED chip and replacing it with a purple light one, lighting technology is fundamentally transformed. For the first time it is possible to render colors accurately with very low energy use and positive effects on health. Compared with other LED lights, the new SunLike Series do not have a blue energy peak associated with eye discomfort and poor sleep patterns.

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Keeping it Cool: The Role of Heat Management in Optimizing LED Technology

Unmasking LED Behaviors: The Crucial Interplay of Heat and Light Performance

For LED technology, from the LED chip to related products such as LED lamps, modules and fixtures, high operating temperature can result in mechanical failure and significant drop of performance.

How a LED behaves when subjected to higher operating temperatures is directly related to its quality. High quality LEDs (such as Nichia or Cree) will function within parameters at high temperatures too, while low quality LEDs will break down, change their color, loose brightness or a combination of these. 

For LED technology, we need to avoid operating at temperatures beyond those specified by the manufacturer. Failure to do so while lead to at least one of the following:
  1. complete failure of the LED
  2. light output is decreased permanently (Lumen Degradation) even if the issue with high temperature is solved
  3. light output is decreased temporally while the LED functions at high temperature
  4. the color temperature of the white LED changes

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UVC Fluence, Dose recommended for disinfection from Viruses, Bacteria, Protozoa and Algae

UV Fluence (Dose) recommended for 90% or 99% disinfection from Viruses, Bacteria, Protozoa and Algae

 When designing, building or installing a UV light, two key questions must be answered first:

"How irradiance does it need to have?"

 

"What is the required exposure time?"

While there are many studies that show the effectiveness of UV light in disinfection or sterilization, a high variance of the results exists, which presents a challenge to find an answer to these questions. 

We will present our recommendations by analyzing the results of 413 reasearch papers, as found in the compilation "Fluence (UV Dose) Required for up to 99% disinfection from Viruses, Bacteria, Protozoa and Algae"  that can be downloaded at the links below:

PDF: Fluence (UV Dose) Required to Achieve Incremental Log Inactivation of Bacteria, Protozoa, Viruses and Algae

The research studies present the fluence required to achieve a log reduction from 1 to 5, for different types of UV sources.

 

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Feeling the Heat: The Crucial Role of Thermal Management in LED Performance

Understanding and Optimizing Heat Management in LED Lighting Systems
Getting the most from a product based on LED technology can be tricky because of one important factor: how operating temperature can result in a substantial difference between the advertised and actual performance of a LED based product.

Important factors in this effect are the LED quality, product design and heat management: how much of the heat generated while in operation is channeled away.

If the heat is well managed, a LED based lighting product will have performance as advertised, long life and will be energy efficient. 

The basics of LED heat management

LEDs use electricity and this process generates heat. This heat needs to be channeled away from the LED in the ambient as efficient as possible. Designing the LED itself and the luminaire for this purpose is called heat management. The heat that needs to be channeled away is directly proportional with the luminous flux and power consumption of the LED.


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How to get the best results from LED Backlighting: A Comprehensive Guide

How to get the best results from LED Backlighting: A Comprehensive Guide

LED backlighting is a popular and versatile lighting solution that can be used in various applications, from linear lighting fixtures to luminous ceilings and illuminated signs. Achieving the perfect balance of total luminous flux and individual LED visibility is crucial for successful implementation. This article delves into the essential aspects of selecting and positioning LEDs for backlighting applications, ensuring optimal performance while meeting project requirements.

Understanding the Basics of LED Backlighting

LED backlighting involves placing light-emitting diodes (LEDs) behind a diffuse cover to create uniform and visually appealing illumination. Common applications include:

  1. Linear lighting fixtures: LED strips or tubes used for accent, task, or general lighting in residential or commercial spaces.
  2. Luminous ceilings: Large, uniformly lit surfaces that create a sense of spaciousness and enhance the aesthetics of interiors.
  3. Illuminated signs: LED backlighting is used to create vibrant and eye-catching signs for branding, advertising, or wayfinding.


 LED pitch and the distance between the LEDs’ emitting surfaces and the lamp cover.

 

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Understanding LED Color Consistency: The Crucial Role of Macadam Ellipse Sorting

Macadam Ellipses LED color sorting (3 step, 5 step): Explained
To understand what Macadam Elipse color sorting is, we first have to know about LED color consistency.

LED color consistency has an easy explanation. Everyone can notice when color consistency is poor, especially in the case of white light.  The image below shows this clearly, the white LED light has different shades. 

Thus, high color consistency means all white LED have the same shade while poor color consistency looks like in the image above. This is the most extreme of cases, with LEDs or luminaries having all the shades of white mixed up: warm white, pure white and cold white in one installation. However, the same phenomenon exists for products marketed as warm white, pure (natural) white or cold white.

White light has different shades

While there is no consensus, warm white light for LEDs has a value of 2500K-4000K on the color temperature scale, pure white 4000K-5000K and cold white 5000K-10.000K.

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LED Strip Heat Dissipation Performance based of LED pitch and base material

LED strips and modules used for lighting fixture use, in general, multiple LEDs.
As operating a single LED generates heat, more is generated when multiple LEDs are mounted on a PCB, due to the mutual effect. As such, in the case of LED strips or modules, the junction temperature (TJ) of each LED gets higher, compared to a single light source. This leads to the decrease in the LEDs lifetime and luminous flux.
For LED strips and modules, a better thermal management is required to minimize TJ and allow a longer lifetime of the installed products. For this purpose, the LED pitch, the PCB base material and the use of aluminum profile must be taken in consideration.

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Impact of cover on Optical Characteristics of LED strips and linear lights

Linear LED light fixtures and LED tubes also feature a cover that protects the LEDs and diffuses the light. This cover is usually made of polycarbonate (a resin) and sometimes of glass. 
The cover has a certain light transmission rate that impacts the light's luminous flux and glare. If a cover has a high transmission rate, it will minimize the depreciation rate of the lamp’s luminous flux by reducing the light diffusion. However, the light of individual LED’s can be visible, increasing the glare effect.
Below, we present an evaluation of four covers to showcase light transmission and glare.
 
Cover A
Cover B
Cover C
Cover D
 
Image
Material
Resin
Glass
Resin
Transparent Resin
Light Transmission
Rate(%)
57
67
77
90

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LED Strips SERIES and PARALLEL circuit connection guide

LED Strips SERIES and PARALLEL circuit connection guide

Basic LED principles:

An LED (light-emitting diode) is a semiconductor light source that emits light when current flows through it. Light is energy in the form of photons that emit when electrons in the semiconductor recombine with electron holes. 

The higher the current flow, the brighter the LED becomes. However, the circuit is not perfect and some of the current is converted to heat instead of light. When the current reaches a certain value, the heat generated is so high that the semiconductor is permanently damaged. In most LED data sheets, this important limit is specified as "Absolute Maximum Current".

Even if the LED operates below the maximum current, the heat will slowly damage the LED, causing its luminous flux (light output) to gradually decrease. The time when the LED luminous flux is only 70% of the initial value is commonly referred to as "LED life".

For LEDs to have a very long life of 50,000h or more, a current level well below the absolute maximum current is required, which is referred to as the "typical" or "recommended" current. 

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