Intelligent LED Solutions

IP stands for Ingress Protection. It is a classification that is assigned to light fitting when they have been evaluated and approved for protection against water, as well as solid objects including dust and dirt. It is something commonly encountered when looking at finished lighting products. For some applications, it is vital to know and acquiring a light fitting with the correct rating is paramount.

You will see the IP rating written as two numbers. For example, IP67 or IP20. The first digit represents the level of protection the light fitting has against dirt and dust particles. While the second digit stands for the degree of protection from water. This number is often more important in applications in environments where water may be present, such as bathroom lighting or outdoors. Any light fitting used in a potentially wet environment should hold a sufficient IP rating to prevent the ingress of dust and water.

So, what do the numbers mean? Well, the higher the value of either digit, the greater is protection is.

Lower IP ratings: Indoor applications:

Many applications will not require a high IP rating, such as general indoor use with no exposure to water or high dust levels (bedroom or living room lighting). In such instances, ratings below IP44 are typically acceptable. Most standard light fitting within your home are rated IP20, meaning that they are not protected against water, but have slight protection against dust.

Mid IP ratings:

Lighting products rated between IP44 and IP65 have more protection against the elements and therefore are suitable for both indoor and outdoor use. Although they are not fully waterproof, so when implemented outdoors, they should be protected from the harshest weather condition and installed in a sheltered location. 

Higher IP ratings:

If your application is subject to harsher weather conditions, then a higher IP rating would be needed. Lighting with IP65 or IP67 are typically considered to be able to withstand water, excluding full submersion. Applications that require these higher IP ratings could include, horticultural applications whereby standard hoses and irrigation systems are used, and dirt is present. As well as, inside showers, wet rooms, pools, and any other spaces with a high chance of contact with water, dirt, dust, and debris. 

Horticulture is being revolutionised by advancements in LED lighting. New technologies enabled by an ever-expanding knowledge base are demonstrating how plants require different spectral illumination and control. We know that water, nutrients, temperature and many other factors all play a key role but light is also an important contributor. 

Why do plants need light?

Since crop cultivation began, all fruit, vegetables, flowers and herbs have been impacted by the sun. Plant growth is naturally stimulated by the duration, spectrum and intensity of sunlight. Photon flux density (PFD), which refers to the intensity that photosynthetically active photons hit the surface area of a plant, greatly impacts a plant’s biomass and growth rate. Furthermore, the spectral power distribution, which refers to the energy levels of the light source, has been shown to have an impact in regulating the morphology and even the colour of certain genotypes of a plant. Finally, the photoperiod, which refers to the timing and duration of light, can effectively regulate the flowering times of certain short-day and long-day plants. These components of light are not exclusive, but they all work together to regulate the overall growth of plants.

Different wavelengths emitted by sunlight contribute to various aspects of plant growth. The plants absorb these useful wavelengths. The spectral composition of the different wavelength regions (blue, green, yellow, red, far red or non-visible UV or IR) is important for the growth, shape, development and flowering (photomorphogenesis) of the plant.

How do plants react to different wavelengths?

Plants do not react the same as the human eye, which reacts to light with the short, medium and long photoreceptors allowing us to see in colour. Plants respond to light with carotenoids which are pigments in the plants responsible for red yellow and orange hues in many fruits and vegetables, and with chlorophyll and phytochromes which regulate their growth. Chlorophyll absorption is linked to photosynthesis and therefore to the growth of the plant. A plant’s phytochromes are sensors which react to the environment and adjust the morphology. The absorption spectrum of the eye is primarily a combination of red, green and blue however a plant will respond differently to wavelengths within the range of 280-800nm.

So plants absorption of wavelengths from either a natural or an artificial source, directly impact upon its growth and appearance. Therefore, it is key to understand what impact different wavelengths have on plants, and why we use the LED colours that we do.

Why does horticultural lighting often appear pink?

A lot of horticultural lighting appears to be pink – this is typical because it is made up of a combination of blue and red light. These wavelengths are most commonly used in horticultural LED lighting. In general, red and blue light are combined to maximise the photosynthetic rate and healthy plant growth as this combination of wavelengths corresponds to the absorption peaks of chlorophyll.

How do plants respond to different wavelengths / colours?

Wavelengths 450nm (deep blue) and 660nm (hyper red) both provide energy for the plant. But the blue light, which is absorbed by cryptochrome within plants, is also responsible for photomorphogenic functions such as stomatal control, stem elongation, and phototropism. While a ratio of red to far‐red light is detected by phytochromes and stimulates stress responses such as elongation growth, apical dominance and flowering.

Far red 730nm LEDs can be used to influence the height of the plant. Exposing a plant to more of this colour wavelength, makes the plant feel like it is in the shadow of a bigger plant, which then triggers the “shade escape reaction” meaning that the plants growth rate is increased. This wavelength can also influence when a plant’s flowers bloom. It can make a plant’s flowers bloom in winter or even prevent them from blossoming in summer.

Although light in the green wavelength range is not easily absorbed and is generally assumed to have a lesser effect on plant growth and photosynthesis, some research has indicated that mixing 24% of green fluorescent LED light (500 to 600 nm) with red and blue LEDs (630 and 470 nm respectively) produces more biomass than other wavelength mixes. This may be because green light can penetrate lower than red or blue light in the plant canopy allowing the lower plant leaves to use the green light for photosynthesis.

Horticultural lighting techniques using coloured LEDs

Coloured LEDs can be utilised in various ways in horticulture, depending on the sort of lighting application and what the end goal is. Here are just a few horticultural lighting techniques:

• Supplemental Lighting – Used to supplement pre-existing natural daylight, in order to enhance photosynthesis and thereby improve growth and quality of plants. Often used in greenhouse settings. Coloured LEDs are perfect for supplemental applications, as increasing quantities of key wavelengths the plants receive, can help give them a boost.
• Photoperiodic Lighting – Used to control the light period by extending the natural day length with artificial light. Useful to extend growth periods during winter months for example, when the hours of daylight are shortened
• Cultivation without daylight (non-supplemental) - Used to totally replace daylight with artificial light for ultimate climate control. Although for this application, white LEDs may also be required as well as colour LEDs, in order to make up for the wavelengths the plants would be missing out on due to the lack of natural sunlight.

What to consider when choosing an LED driver:

Constant current (CC) or Constant voltage (CV)

Depending on your LED modules and application you may require CV or CC.

• CC LED drivers are a popular choice for LED applications and are suitable for use with LED chains or single LEDs operating in series. Series refers to multiple LEDs mounted and linked together with the current flowing through them all. Within a series, if the circuit is not broken, all LEDs will receive current and operate as expected. However, if the circuit is broken, none of the LEDs will be powered. CC LED drivers keep a constant electric current throughout an electric circuit by having a variable voltage. In comparison to constant voltage CC LED drivers tend to offer a more efficient circuit and better control.
• CV LED drivers, on the other hand, supply a set voltage to the electronic circuit. CV LED drivers are ideal for a parallel circuit made up of multiple LEDs. For example, they are best suited for LED modules with either an on board or a current limiting resistor, such as an LED strip. The voltage requirement of the entire LED chain must match the voltage output of the CV LED driver.

IP Rating 

For an LED driver to be used outdoors, an IP rating of IP65 is required. Likewise, if the application requires a driver that can be submerged in water, IP67/IP68 will be needed. Alternatively, if the application is indoors and the LED driver does not need protection from the elements, a driver IP rating of IP20 would be suitable.

Dimming 

Your LED module and application may need to dim the brightness of the LEDs. Dimming is possible via several methods. These include:

• 0-10Volts - For direct current voltage (DC) between 0 and 10 volts.
  This can produce light at varying intensity levels. 0-10V dimming is the simplest control system for lighting, providing smooth operation and dimming down to 10%, 1%, and even 0.1% light level.
• Mains dim - Phase cut, triac dimming, leading edge, or trailing edge.
  This reduces the electrical energy level flowing through the LEDs, thereby causing them to dim.
• Pulse-width modulation (PWM) - A common type of dimming used to adjust the current in white-LED driver devices.
  PWM dimming takes a rectangle waveform with a variable positive duty cycle and adjusts the LED current proportionally.
• Dali - These dimmer switches use a digital protocol to send a dimming control signal to a driver down separate wires to the mains supply. They do not directly control the energy passed to the driver. 

Wireless

This works by sending wireless signals through your home Wi-Fi or mesh network.
These wireless switches can control lighting, ceiling fans or anything connected to the switch, including adjusting the brightness of your lights.

Output current 

Your driver’s output current needs to match the requirements of the LED you are driving. I.e., if your LEDs need 350mA then your LED drivers output needs to be 350mA also. Output current is a value given in amps (A) or milliamps (mA). 1000mA make up 1A. To use a CC driver, make sure to check the current requirements of your chosen LED(s). This can typically be found within the LED’s datasheet.

Your LED’s required current must match or fall within the output current range of the CC LED driver. Using a higher current than recommended for the LED will wear the LED out a lot quicker, reducing its lifetime. Whereas running the LED at a lower current would have the opposite effect.

Output power 

Measured in Watts (W), the LED driver you choose should have an output power that is at least the same value as your LED’s power requirements. Ideally though, the output power should be higher than the LED’s power needs. This is because if the driver’s maximum output is equal to the power requirements of the LED, then the driver will be operating at full power. This may shorten the LED driver’s life span.

Secondly, the power requirement of the LEDs tends to be calculated as an average, with tolerance added on top for multiple LEDs, so ideally you should have a higher output power from the driver to factor this in.

Output voltage 

Measured in Volts (V), referring to the voltage produced by the LED driver and supplied to the chosen LED(s). For CC LED Drivers, the output voltage needs to exceed the voltage requirements of the entire chain of LEDs you are trying to drive. For CV LED drivers, the voltage required by your LEDs needs to match the output voltage of the LED driver.

Dimensions 

Make sure the LED driver you chose fits any space limitations you may have.

Lifetime

All LED drivers tend to come with a lifetime expectancy of thousands of hours. This value is known as MTBF, which is the ‘mean time before failure’. To extend the lifetime and reduce maintenance costs and time, make sure to run your chosen LED driver with the recommended outputs.

Suggested Products

The ILS team is here to help you select the optimal LED driver for your project. We offer a variety of OSRAM DS power supplies, as well as our own ILS power supply product range.

• IZC035-004F-4065C-SAL – ILS Constant Current LED Driver, 4W, 100V, 350mA, IP65
• IT-FIT-4/220-240/400-CS-I – OSRAM ICUTRONIC FIT Compact Constant Current LED Driver, Non-dimmable
• OTi-DALI-10/220-240/700-NFC-I – OSRAM OPTOTRONIC Intelligent Compact Constant Current LED Driver, Dimmable
• OT-SLIM-60/220-240/24  – OSRAM Constant Voltage LED Driver 24V, 60W

What is Infrared?

Infrared (IR) is a type of electromagnetic radiation with wavelengths outside of the visible light spectrum. It was discovered in 1800 by William Herschel, who conducted experiments measuring the difference in temperature between wavelength colours. This led to the discovery of IR, with the warmest temperature measurements sitting beyond the red end of the visible spectrum. Although humans cannot typically see IR wavelengths, weaker ones may emit a visible red glow. A red glow is seen as the IR wavelengths sit just past the visible red spectrum of light. So, although most IR wavelengths are not detectable by sight, humans can detect IR through its emission of heat. These characteristics enable IR to have many interesting and useful applications.

Electromagnetic Spectrum – Where does infrared sit?

What are infrared LEDs?

Infrared LED (light-emitting diodes) operate like any other LED but use different materials to produce a different spectrum of light. IR LEDs emit wavelengths at the top end of the electromagnetic radiation spectrum beyond the visible. But unlike LEDs that emit wavelengths and colours within the visible spectrum, IR LEDs are not used to provide illumination in the same way. IR LEDs can have many interesting applications, which will be explored below.

Do infrared LEDs emit heat?

Although IR radiation does emit heat, most applications use IR for its unique illumination traits rather than heat. Such applications use high-power IR wavelengths to illuminate large distances at higher resolutions which leads to heat being emitted and contained within the LED. Thermal management, such as heatsinks and thermal interface materials (TIM), is used to cool and draw heat away from the LED.

What are infrared LEDs used for?

Image source: amsOSRAM

IR LEDs are used in many different areas, both in the home and in industry. Let us take a closer look at some of their applications.

Remote controls: IR LEDs are commonly used for short-range communication such as remote controls for TVs, air conditioners, and other electronic devices. Remote controls contain an IR LED which emits pulses of non-visible infrared light to convey a message to a receiver.

CCTV and security cameras: Almost all objects emit some infrared radiation or heat, which can be detected via sensors. This makes IR useful for detection and sensing applications such as security cameras, automatic number plate recognition, and night vision goggles. These thermal imaging cameras use high-power IR LEDs placed around a camera lens to capture IR images in low or zero-light conditions. This allows a scene can be illuminated and monitored by a camera.

Motion sensors: IR LEDs are used in motion sensors to detect movement and trigger alarms or other actions. These sensors detect the infrared energy emitted as heat by humans and animals. Any increase in IR will be detected by the sensor, triggering a response, and notifying that someone has approached within its range.

Medical equipment: IR LEDs are used in medical equipment, such as pulse oximeters, to measure blood oxygen saturation (SpO2). Pulse oximetry measurement usually uses two different wavelengths. The difference between IR and red light absorption is used to determine the blood oxygen content. Pulse oximetry can also detect sleep apnoea in patients.

Automotive applications: IR LEDs are used for detection in automotive applications, such as collision detection systems and driver monitoring systems, that are designed to alert drivers of the presence of objects or pedestrians around the car. IR is the ideal solution here as it relies on heat to detect rather than illumination.

Barcode scanners: IR LEDs are used in barcode scanners. They direct IR wavelengths across the barcode surface. The reader then measures the pattern and quantity of the light reflected off the barcode. The light emission received is converted into data by a decoder and forwarded to a computer.

Smart watches and health monitoring: Heart rate monitoring typically comprises of an IR wavelength. An IR LED will emit light, which penetrates through the skin and is absorbed by the blood vessels. The returned light and subsequent data allow metrics such as heart rate, blood oxygen level, and even blood glucose level to be measured. This technology is often implemented in smart watches as well as other medical devices.

ILS Infrared LED Modules:

ILM-IP01-85SN-SC201-WIR2000.   -    3782397

ILM-IP01-94SN-SC201-WIR200.     -    3782398 

ILH-IO01-85SL-SC211-WIR200.      -    3585883 

ILH-IW01-94SL-SC211-WIR200.     -     3585892

If the coronavirus pandemic taught us anything, it is that bacteria is everywhere. Every day, we are constantly at risk of contact with bacterial and viral infections. This risk is particularly prevalent when passing through places that have a lot of footfall such as public transport offices, and supermarkets.

This is why UVC disinfection is increasingly popular and becoming more widely used. It is no longer solely used in large-scale industrial and medical settings. It is becoming part of our daily lives.

Bacteria and viruses indoors

Much of our usual day is spent indoors, whether that be at work or at home. Within public spaces like offices, shops or hospitals, the risk of encountering bacteria is high. We frequently encounter bacteria and viruses as they multiply on surfaces such as supermarket merchandise, elevator buttons, escalator belts, tables, chairs, and even droplet infection during conversation.

Manual chemical cleaning in these spaces is time-consuming and prone to human error. Consequently, some hospitals and other public spaces already use UVC via autonomous UVC sterilisation robots. Such innovative devices can disinfect large or small spaces more effectively than manual cleaning. The UVC radiation emitted targets and destroys harmful microorganisms, with more consistent and accurate coverage than manual cleaning.

Bacteria and viruses in the home

Even at home, bacteria and viruses are ever-present. Risk of infection and transmission is greater when rooms are limited in size and poorly ventilated. Commonly touched surfaces such as doorknobs, toilet flushes, taps, TV controls and light switches can harbour bacteria and viruses. Therefore, using UVC disinfection to neutralise these harmful microorganisms in our homes, can provide peace of mind.

UVC technology is used in smaller handheld devices that directly irradiate and sterilise surfaces. Such devices have been designed for easy everyday use. One key benefit of using UVC radiation to disinfect in the home is the reduced use of toxic or harsh chemicals which are commonly found in household cleaning products. UVC radiation is certainly more environmentally friendly way of eliminating 99.99% of bacteria, with immediate effect upon exposure. Therefore, it is ideal and convenient for home usage.

Bacteria and viruses on public transportation

Vast numbers of people pass through public transport every day. Particularly during popular commuting hours, when buses and trains will fill with individuals heading to and from work. Risks of bacteria transmission in these settings are high, not only from droplet infection but also from physical surfaces. Whether on a train, plane, bus or car we touch many different surfaces including handrails, ticket machines, entry barriers, and handles. This is why it is necessary to take measures to reduce the spread of bacteria and viruses.

Limited air circulation in aeroplanes and underground trains have the perfect conditions to breed and transmit airborne pathogens. UVC air purification is another growing application which helps to combat this problem. It is often used on planes and trains to effectively eliminate airborne viruses and bacteria.

Air is circulated through air filters, which is subjected to UVC radiation emitted from LEDs. This process destroys harmful microorganisms carried by air and has a 99.99% effectiveness rate. UVC LEDs can be implemented within larger systems for use indoors, as well as compact systems for small spaces and inside vehicles.

Image source: Stanley Electric Co.

ILS UVC LED modules

ILS offer three different primary lens options (60°, 90° or 130°) which control light distribution over the target area. ILS's wide range of UVB & UVC LED solutions are built using UV LEDs from TSLC, Stanley and OSRAM. The variety of module sizes, wavelengths and powers allows users to select their most optimal wavelength range. These options also give designers more flexibility to meet the power requirements for obtaining the desired level of disinfection.

Sources:

https://www.stanley.co.jp/e/product/uvc_product/sterilization/

https://www.stanley.co.jp/e/product/uvc_product/sterilization/air.html

The OSLON Square Uniform is an innovative device from amsOSRAM. These LEDs deliver superior colour uniformity, without a significant drop in brightness.

This device is primarily designed for use in indoor spotlighting, museum lighting and wall washing. Being built on a ceramic package allows for superior robustness and long lifetimes.

The OSLON Square Uniform is available in multiple white wavelengths, including 2700K, 3000K, 3500K and 4000K, all with a minimum CRI of 90. By adding a diffuser layer on top of the phosphor the colour uniformity of the LEDs has been improved, with a superior colour over angle.

So why is this important? Colour over angle is particularly important when using secondary optics with single source LEDs. As demonstrated in the illustration above, without the diffuser layer blue light from the “blue pump” has escaped from the outer edges of the LED, causing a blue “hue” or “halo” effect. The use of secondary optics multiplies this effect significantly.

The primary design application of the OSLON Square Uniform LEDs is for use in gallery/museum lighting. Previously customers may have experienced issues of artwork or displays not looking as they should do under conventional lighting. These new LEDs from amsOSRAM offer a solution for this.

Intelligent LED Solutions (ILS) have carefully selected a range of light engines that are an ideal match for this LED. These light engines are compact, powerful LED light sources, all built on aluminium substrates for optimal thermal management.

LED Modules

PowerStar modules are ideal for prototyping and integration within light fittings. They can be matched with secondary optics from LEDiL thanks to mounting holes on either side of the LED. PowerStars are supplied with 200mm wires as standard.

But if you are looking for a 24V linear design that is ideal for plug and play, the 6 strip is your solution. A compact size of 300mm, this strip can be designed easily to luminaires and can be linked to create longer chains.

Ultraviolet light is electromagnetic radiation that sits outside of the visible light spectrum and comprises of 380-740nm. The UV spectrum of 100-400nm is invisible to the human eye. Out of the light that reaches the surface of the earth, only 5-6% of it is UV. The UV spectrum consists of four distinct categories, each with their own wavelength characteristics and applications.

• UVA = 315-400nm. The least dangerous wavelength and the wavelength we receive most strongly from the sun. The majority of UVA passes through the ozone layer and reaches the surface of the Earth. It is responsible for tanning our skin.
• UVB = 280-315nm. Slightly stronger wavelengths which are responsible for Vitamin D synthesis and skin burns. Absorbed by the ozone layer, only some passes through.
• UVC = 200-280nm. Does not typically penetrate the ozone layer. It is the wavelength most commonly used for disinfection applications.
• UVV = 100-200nm. Strongly absorbed by water and air and can only be transmitted in vacuum. Does not penetrate the ozone layer or reach the surface of the Earth.

From the two types of UV that reach the Earth's surface, UVA makes up about 90% and the remainder is UVB. Although UVC does not reach the Earth, it possesses the highest sterilisation effect compared with other types of UV light. UVC is therefore ideal for disinfection as it can cause molecular damage to cells. UVB also has this capability but to a much lesser extent. UVB radiation from natural sunlight is the main harmful component. These rays can damage human cells, causing sunburn and even skin cancer.

Unlike UVC, UVB can only disrupt DNA cells and cannot kill microorganisms efficiently. Microorganisms are significantly smaller than human cells, so in order to break through their cell structures, smaller UVC wavelengths are needed. Within a microorganism, the nucleus cell contains thymine, a chemical element of the DNA/RNA. Thymine absorbs UVC at a specific wavelength of 253.7nm, this UVC light will modify microbial DNA by thymine dimer formation. This alteration causes severe disruption in microbial replication as well as in the processes of protein expression that are vital for the survival of cells. Cellular breakdown is triggered, rendering the cell no longer able to multiply and survive.

The UVC Disinfection Process:

1. Unable to metabolise and replicate, the organism cannot cause or spread disease.
2. UVC high-energy photons are then absorbed by cell proteins and DNA/RNA.
3. The protein structures within the microorganism are damaged, causing metabolic disruption. 
4. The DNA/RNA is chemically altered, meaning that the organism can no longer replicate.
5. Unable to metabolise and replicate, the organism cannot cause or spread disease.

It should be noted that UVC light does not discriminate when it comes to ruining genetic material. This wavelength can damage human and animal skin and eye cells. Prolonged exposure to UVC radiation can cause sunburn, skin damage and conjunctivitis and even cancer. Whenever dealing with UVC light, the skin and eyes must be fully protected against exposure, and the light source should not be directed onto skin or eyes.

UVC LEDs

Widely used for their disinfection purposes, product development has advanced rapidly in recent years. LED does not use mercury, meaning that it has a low environmental burden and is distinguished by its compact size and long life. Whatever the purpose, UVC is proven as an effective method of disinfection and an efficient defence against pathogenic bacteria. UVC LED modules are available in a variety of sizes and wavelengths.

See our selection of UVC modules here 

Sources:

https://www.stanley.co.jp/e/product/uvc_product/about/

https://docs.rs-online.com/ae37/A700000008705860.pdf

What is Spectroscopy?

Spectroscopy allows the composition, physical structure and electronic structure of matter to be analysed. This is achieved through the examination of the interaction between matter and electromagnetic radiation, as a function of the wavelength or frequency of the radiation.

When electromagnetic radiation is passed through an item, the photons may be absorbed, reflected or refracted. Information about the emitted and absorbed spectra can then be used to gain information about the item. This is possible because the ratio of light that is reflected or absorbed varies from object to object, resulting in a unique molecular fingerprint for each item.

What does this mean in the modern world and in our day-to-day activities?

Picture yourself in a supermarket and you wanted to check if the strawberries in front of you were sweet without touching them. Using a broadband LED, a spectrometer and some code, your smartphone could look at the molecular structure and answer this.

How is this achieved by OSRAM’s new technology?

By utilising a blue pump and a specific mix of phosphors, OSRAM has developed a broad spectrum of 650-1050nm. A broad range of wavelengths emitted allows for a wider range of objects to be analysed more accurately.

Technology is moving forward incredibly fast and with it, things are getting smaller and more powerful. In 2017 there was the OSLON Black Flat, a 3.7x3.7mm package. The OSLON Piccalo 1616 SFH4737, this device is 3.6 times more intense and significantly smaller than its predecessor, delivering 74mW in NIR (650-1050nm).

Such a small package, but how can I use it?

With its extremely compact dimensions of just 1.6mm x 1.6mm x 0.9mm, the OSLON P1616 SFH 4737 is the world's smallest near-infrared LED (NIRED) for spectroscopy applications available in the market; it is not something that is easily handled by hand.

Intelligent LED Solutions (ILS) have introduced a LED Light engine designed specifically around the OSLON P1616 LEDs. As a result of this minuscule LED, we have developed a range of tiny MicroOSLON boards. Our MicroOSLON modules measure 11mm in diameter and are compact, powerful LED light sources built on aluminium substrates for optimal thermal management. Available with 200mm wires as standard.

Part Number	Description	Farnell	Image
ILM-IP01-BBEM-SC201-WIR200.	ILS OSLON P1616 MicroOSLON Broadband Emitter LED engine, with 200mm wires. >650-1050nm.	3782399