Tag Archives: LED modules

Tunable White – Achieve color temperature from 2700K to 6500K with one LED module

Tunable White color changing

The Tunable White is becoming a big trend in residential and office lighting. I introduced one color changing LED product, Dim-to-Warm LED, in the earlier post.  In this post, I will tell you about the Tunable White module. Its color temperature can be changed freely from 2700K to 6500K. This means that you can achieve warm light like incandescent lamp and daylight with only one module. In addition to changing the color temperature, you can also dim the brightness.

Why color changing and Tunable White is a trend? How does it impact humans?  Let me shed light on that.

As we know human mind reacts to brightness and temperature of light. Cool light (e.g., daylight) has a refreshing effect and helps us work at school, office, where ever effective work is needed. Where cool light refreshes, the warm light has a comforting and relaxing effect. Naturally, these lights are presented in daytime during sunrises and sunsets.

 

Tunable white color chart

 

How to use Tunable White?

With Tunable White module, you can create better environments for both working and living. You can maximize productivity and improve concentration. Here are just some examples of the usage, but really there are countless ways to use Tunable White. 

One great use for Tunable White is offices. You need a lot of concentration to work effectively. This can be achieved with decent lighting. With this module, as said before, you can control the cool and warm light and dim the brightness. This gives the opportunity to select the right color temperature for office during the daytime.

In residential usage, Tunable White gives a possibility to simulate circadian rhythm. Connect the Tunable White to a control unit, it can change the color temperature automatically by daytime. This way you can enjoy cold refreshing light by midday and get the comforting feeling of warm light by evening.

Now we know some examples, but what kind of luminaires Tunable White is suitable for? Tunable White module is very small sized. This gives options to use it in the wider range of luminaire types.

Here are some examples:

  • Downlight
  • Spotlight
  • Indirect lighting
  • Table light
  • Decorative light

How does it work?

Citizen Tunable White module is made by using “multi-chip” technology. That means it’s made of tiny LED chips that are combined into the same module. Because of its very small size (LCN-C01A is only 15×15 mm), smaller luminaires can be made than before. The small size also gives more even light. The spots between cool and warm dies are almost invisible, which guarantee more smoothly light.

It is made from cool (6500K) and warm (2700K) diodes. The color temperature changes by controlling the output of the two different colored LEDs. LED’s brightness depends on the current; reducing the current the brightness reduces. These features give the option to dim and change the color temperature of LED.

Color curve of Tunable White module.

The Tunable White module has linear color curve because it has two primaries (6500K and 2700K). Advantages of two primaries are greater efficacy and simplicity. As seen in the diagram above, the linear color curve is located under the Black Body Locus (B.B.L.). That affects the color of the light and brings some colors up. You can get white light without greenish tint. This improves contrast in other colors.

A suitable driver needs to have two channel outputs to control CCT and intensity of the light. So, you need 1-10V, DALI or another two-channel driver to control the Tunable White luminaire.

Our high-quality Moons S Series Intelligent Drivers have great compatibility with the Tunable White module. They also have deep dimming from 100 % even to 0,1 %. You can program correct tuning and dimming curves for your luminaire. With Moon’s drivers, you can get everything out of this LED module.

If you have anything to ask, please don’t hesitate to contact us. For more information please download the presentation and the datasheets link down below.

Download Here

Why Should You Choose the New aLED Module

We redesigned our aLED-modules based on customer and market feedback. Here is  a brief explanation on what is different compared to previous version. And why I think you should consider using aLED modules.

 

Figure 1. New aLED Modules with examples of different connector locations.

Better efficacy (159-191 lm/W)

We upgraded the SMD LEDs used in the modules to better suit our customers’ needs. aLED modules now have efficacy from 159 lm/W to 190 lm/W. Efficacy depends on the color temperature and you can see the efficacy by CCT here:

  • 2700K (174 lm/W)
  • 3000K (177 lm/W)
  • 4000K (185 lm/W)
  • 5000K (191 lm/W)

Better placement of LEDs

We have changed the design of our aLED module. LEDs are now placed on the center line of the module so the installation of optics is easier.

aLED modules dimensions have also changed. New modules are now either 279.2 mm or 558.4 mm in length and 20 mm or 40 mm in width. 

Different options for connectors

It is now possible to order aLED modules with connectors either on the frontside or on the backside. Traditionally the connectors have been on the frontside, but these new backside connectors allow you to hide the wires behind the module and inside the profile.

For longer luminaires, there is a possibility to use backline, so you won’t need long wires. Short wires to connect multiple modules together will be enough (figure 2).

Figure 2. a) How to connect modules without back line option. b) How to utilize the back line option of the aLED modules.

Long lifetime

Thanks to the upgraded LED, the lifetime of aLED modules has also increased. You can see the lifetime prediction below. But to be brief: at maximum TC temperature (85°C) the lifetime (L70B50) is over 100.000 hours (figure 3).

Fikure 3. The lifetime of aLED Module (L70B50)

Friendly to environment

On top of high efficacy and the possibility to save energy, aLED modules are also recyclable. You can recycle all parts of module, even the PCB.

In addition to all these changes aLED modules prices have also dropped to more competitive level.

You can find the technical details of 4000K modules from the table below. You can download the datasheets of these new modules by clicking here.

Product Code Color Temperature (CCT) Color Rendering (Ra) Luminous Flux (lm) Forward Current (mA) Voltage (V) Power (W) Efficacy (lm/W) Length (mm) Width (mm)
CALOSNU0405 4000 80 1182 600 11.6 7.0 170 279.2 20
CALOSNU0410 4000 80 1224 600 11.0 6.6 185 279.2 20
CALOLNU0805 4000 80 2363 600 23.2 13.9 170 558.4 20
CALOLNU0810 4000 80 2448 600 22.1 13.3 185 558.4 20
CALOLHU1610 4000 80 4895 600 44.1 26.5 185 558.4 40
CALOSND0405 4000 80 1182 600 11.6 7.0 170 279.2 20
CALOSND0410 4000 80 1224 600 11.0 6.6 185 279.2 20
CALOLND0805 4000 80 2363 600 23.2 13.9 170 558.4 20
CALOLND0810 4000 80 2448 600 22.1 13.3 185 558.4 20
CALOLHD1610 4000 80 4895 600 44.1 26.5 185 558.4 40

 

Download Datasheets

 

In addition to these new models, all our previous module models are also still available.

How to Connect LED Modules into AC Network

In my earlier post I went through the procedure of how to physically connect a single LED component into an AC network. The connection was made between COB LED and the LED driver. When connecting LED modules (LED diodes assembled on the PCB board) you do it pretty much the same way with slight differences.

Connecting an SMD LED module into the AC network

As with a COB LED component, you will need a suitable driver for your module (see: how to choose a constant current LED driver).  You connect the positive terminals and the negative terminals of the LED driver and the LED module together to create a closed electrical circuit.

The difference to connecting a single LED component is that you may have to connect several LED modules into the same LED driver. In such case, you have to use series connection. This means that you still have to create a closed electrical circuit formed by the LED driver and these LED modules on the secondary side. You arrange the primary side like you would with single LED components. On the secondary size you connect the positive terminal of the first LED module (leftmost module in Figure 1) into the positive terminal of the LED driver. Then you connect the negative terminal of the last module (rightmost module in Figure 1) to the negative terminal of the LED driver. See Figure 1 below that shows all connections between the components.

Figure 1. Connection of LED modules into AC network through the driver.

How do you make other connections? Series connection means that you always connect the negative terminal of the previous array to the positive terminal of the following array in the chain. See again Figure 1. The output voltage of your LED driver defines how many LED modules you can drive with one driver. In case of Figure 1, one LED driver drives three LED modules. If voltage over LED module is for example 12V, the output voltage of the LED driver should exceed 36V. In the real world, you have to take into account tolerances. So in this case, 40V can be used as target for the driver maximum output voltage.

In the same way, you can connect multiple COB LEDs in series. This may be the case when you need vast amount of light.

How to actually do it?

As for physical connections of SMD LED modules, there are four options:

  1. PCB terminal block connectors
  2. Soldering
  3. Wire-to-board connectors
  4. Board-to-board connectors

PCB terminal block connectors are quite popular. They are soldered on the PCB board in the reflow process (in reflow oven) after the assembly process. You push the wires into those PCB terminal blocks in the same way as you would push the wires into the push-in terminals of solderless connectors in the single COB case.

Figure 2. PCB terminal block connector (2-pole)

Soldering is an option, if there are separate soldering pads reserved on the PCB to solder the wire(s) with tin. Soldering is usually a more cost effective option.

The numbers 3 and 4 are the special cases when you wish to interconnect two modules with each other. I’ll skip them for now and save them for later post.

If you’re interested in aLED’s new, improved LED modules, read more over here.

Feel free to drop a comment if you have questions on this topic.

FAQ: aLED Modules

Q:You have the driving current 700mA written in the datasheet of your LED module.  Can I use smaller driving current?

A:Yes, you can use smaller current. The current value 700mA mentioned in the module’s data sheet is so-called nominal/typical value that corresponds to the value Citizen announces for voltage and luminous flux (lumens) of the diode used in that LED module.

The minimum current is defined by the diode datasheet and in our 700mA modules the minimum current is 70mA. But you can also use the larger current. The maximum current is 1190mA. Please notice that you have to take care of cooling of the module in case that you use the maximum current. The warmer the module, the lower the lumen output and the shorter the lifetime.

CALC-0814 Absolute Maximum Ratings Found From the Datasheet

CALC-0814 Absolute Maximum Ratings Found From the Datasheet

Q: What is the IP classification of your aLED modules?

A: It is basically IP00, because if our LED arrays are not placed inside the luminaire, they are subject to dust and moisture. So if you need IP classification for your luminaire, please ensure that the luminaire casing has the desired IP classification.

Q: Ok, your aLED modules are classified as IP00, can they then be potted or protected from dust or moisture with some special coating?

A: Basically if you want to cover them with some coating or even pot them, you have to always contact the supplier of that coating or potting material to find out how it affects the LED components. Usually LED manufacturer gives some warranty for their products but this warranty applies only under certain pre-specified constraints or conditions.

Additionally, using coating may alter, and probably does so, optics of the LED components from the characteristics announced in the datasheet of the LED component manufacturer.

So basically you can use potting or special coating, but you should always check how the process affects the module.

Q: How the driving current affects the lifetime of LED module?

A: The lifetime estimations curves, lifetime hours versus temperature TC, are informed for the LED modules at their maximum rated current. That means that maximum condition is used and then lifetime hours are announced at different TC temperatures. The TC point is found in every LED module and is usually located near the soldering terminal, anode or cathode, of the LED diode located near the center of the module.

CALC-0814 Lifetime Estimation curves

CALC-0814 Lifetime Estimation curves

Higher current means higher Tc point temperature and therefore it means shorter lifetime. On the other hand, lower driving current means lower Tc point temperature and therefore longer lifetime.

Q: Are your modules MacAdam 3-step compliant?

A: Our aLED modules follow color consistency in MacAdam 3-step. This means that from production batch to production batch color coordinate values stay within the MacAdam 3-step ellipse. This means that our modules are MacAdam 3-step compliant.

Depending on the CCT, variation in Kelvins is different for MacAdam 3-step, being ±65K for 2700K and ±140K for 4000K.

For 5000K and 6500K our LED modules are only within ANSI binning, not within MacAdam 3-step.

Q: How many aLED modules  you can drive with one 50W/90W 700mA driver?

A: It depends on the module, of course. For the sake of an example lets look at CALC0814-M17W1.

First of all, as you can see from the module’s datasheet, the power is 700mAx24.16V = 16.9W. This is power when the module is driven with 700mA typical current. If you use one 90W driver, you can drive 5 module in series connection.

Let’s do still check calculation. As given by the module’s datasheet, the maximum voltage of the module is 26.4V if all LED diodes are at maximum value of voltage binning range. This is unlikely, but should be checked anyway. Total voltage of 5 modules in series is 5×26.4V = 132V. In our example case the LED driver’s maximum output voltage is 129V. However, the case that all 40 diodes in series connection would have 3.3V (maximum voltage of voltage binning range) is very unlikely. With typical rated value of 3.02V given in the diode’s datasheet, total voltage of 5 modules in series is 40×3.02V = 120.8V, which is within driver’s output voltage range.

So 4 modules is definitely ok. Probably you could drive five, but then we would need to check that they all are from the typical binning.

If you use 50W driver, you can safely drive only 2 arrays in series connection. In our example case the LED driver’s maximum output voltage is 72V. If you drive 3 arrays in series, even the typical voltage is 3×24.16V = 72.48V, which is too much for the driver.

Q: How do you calculate aLED module’s total voltage and total current.

A: We use the information of the diode and the information how many diodes there are in series and how many in parallel.

Circuit Schematics for CALC0814

Circuit Schematics for CALC0814

Let’s take CALC0814-M17W1 as an example. Numbers ‘08’ and ‘14’ refer to electrical configuration of the diodes in the module. First number, ‘08’, refers to how many LED diodes are in series between the + and – terminal of the array.  Second number, ‘14’, refers to how many LED diodes are parallel in one LED chain. In this example, there are 8 pcs of LED chains in series and 14 LED diodes connected in parallel in each LED chain.

Typical value for the diode is 50mA and therefore there is 700mA going through each chain (14x50mA). That gives the total current of the module. With this typical current of 50mA, the diode forward voltage is 3.02mA and there are 8 LED chain in series in this module. This means the typical total voltage of the module is 24.16V (8×3.02V).

Q: aLED modules have quick connectors. Can I use soldered wires instead of quick connectors?

A: Yes, you can. If there are no separate solder pads for soldering wires, you can use quick connector solder pads but in this case the connector is not assembled in the assembly process. In some aLED modules both options are possible simultaneously.

Please note, that with different connectors, the delivery time might be little longer.

If you have some other questions, that were not found in this list, please feel free to ask me. I will answer to you directly and add the general questions to this FAQ later.

Tero Nurmi
Product Manager
aLED Modules
tero.nurmi@light.fi

How Lifetime Affects the Energy Savings of a Luminaire

Generally, when selecting LED luminaires, the attention is drawn to energy consumption. Efficacy, therefore, the power consumption, is the most important selection criterion. But do you pay attention to the lifetime of the luminaire? What happens if the better efficacy luminaire has shorter lifetime? This means that you may have to renew the luminaires much quicker. This adds expenses and eats off the savings from the electricity bill.

Lifetime of LED Light Source

Compared to traditional light sources, the lifetime of an LED light source is long. When a traditional incandescent bulb or a fluorescent tube runs out of its lifetime, it can’t be used anymore. It either won’t produce light or starts to flicker. LED only loses some of its brightness and is, at least in theory, eternal.

This is the reason why the lifetime of LED light sources is measured in a different fashion compared to the traditional. The lifetime of a traditional light source means literally lifetime. LED’s lifetime tells that at what point the amount of light drops below the desired value.

The terms for LED Lifetime:

  • L70, L80, LXX = How much of the original lumens are still available. For example L70 means that the light source still produces 70% of the original lumens. So if the light source produced 1000lm at the beginning, this has dropped to 700lm.
  • B50, B60, BXX = How many light sources are below the given lumen value. So e.g. B50 means that 50% of the light sources don’t produce the desired amount of lumens anymore.

Typically the lifetime is given as a combination of these two. For example L70B50: 60.000h means that after 60.000 operational hours 50% of the light sources still produces at least 70% of original lumens.

aLED Moduulin elinikäennuste

Lifetime estimate of aLED module

The lifetime can also be given using only the L-value. For example L70: 60.000h. Then the manufacturer doesn’t actually promise how many of the luminaires are still over 70% after 60.000h.

Taking Lifetime into Account When Selecting Luminaires

Let’s assume that you are lighting a space that has 1000 luminaires. For example a shop. You have narrowed your luminaire choices down to two: Option A and Option B. Currently the space has fluorescent lighting and more specifically 58W T8 luminaires, which produce roughly 4000 lumens each. Here are your options:

  • Option A
    • Luminous Flux :4000 lumens
    • Efficacy 150 lm/W
    • Power: 26.7 W
    • Lifetime L70B50: 50 000 hours
    • Price 120€/Luminaire
  • Option B
    • Luminous Flux :4000 lumens
    • Efficacy 130 lm/W
    • Power: 30.8 W
    • Lifetime L70B50: 90 000 hours
    • Price 120€/luminaire

It’s easy to choose option A. The power consumption is lower as the power is around 4 watts smaller. For example in your 1000 luminaire space this means 4kW and a significant savings in your electricity bill.

When you know the daily operational hours, you can calculate the annual electricity consumption and compare that to the old solution. For the sake of an example, let’s assume that your shop is open for 14 hours a day. When you add the time for cleaning etc., your daily operational hours are 16. At least in this example.

This way you get the following math:

  • Annual operational hours: 16h*365= 5840 h/year
  • Price of electricity: 0.1€/kWh
  • Traditional (58W Fluorescent)
    • Annual electricity consumption: 1000*58W*5840h=338720000Wh= 338720kWh
    • Electricity bill: 338720*0.1=33 872.00€
  • Option A:
    • Annual electricity consumption: 1000*26.7W*5840h=155928000Wh=155928kWh
    • Electricity bill: 155928*0.1= 15 592.80€
  • Option B
    • Annual electricity consumption: 1000*30.8W*5840h=179872000Wh=179872kWh
    • Electricity bill: 179872*0.1=17 987.20€

 

Both LED options drop the electricity bill down to half of the old solution, saving you a lot of money. Option A saves a little bit more, thanks to the better efficacy and lower power consumption.

In short term, option A would be the better solution. As it saves more per year. Option A saves annually around 2.4k€ more than Option B.

However, it is very rare that investment this size is made with a one, two or even five years scope. That’s why we should do the math for a longer period.

When we take the lifetime into account, the situation changes a little.

Let’s first calculate the lifetime in your application. When the daily operational hours are 16, the annual operational time is 5840h, as calculated above.

With this, we can transform the lifetime into a more understandable form:

  • Option A:
    • 50 000h/5840h=8.6 years
  • Option B:
    • 90 000h/5840h=15.4 years

So you would have to change the option A after 8 years while the option B can still light your space for 7 more years (15 in total).

When we look at the total savings caused by the luminaires, the numbers look like this:

Savings in electricity bill after luminaire change

Savings in electricity bill after luminaire change

Lifetime (a) Option A Option B
1  17 582.29 €  14 447.26 €
3  52 746.88 €  43 341.78 €
5  87 911.47 €  72 236.31 €
10  55 822.93 €  144 472.62 €
15  143 734.40 €  216 708.92 €
20  111 645.87 €  168 945.23 €

As you can see from the calculations and the chart above, the option A is better in the short term. But when you look for a long term savings, the option B’s longer lifetime kicks in before the investment reaches 10 years. You will have to replace the option A almost twice as often as option B.

So when you look at the investment in a long-term, the lifetime becomes very important.

When choosing luminaires, you should focus your attencion to both: efficacy and lifetime.  The more expensive the luminaire and the investment is, the more important the lifetime is.

How to select modules + driver package

In this blog post we concentrate on how to design a LED lighting package as a whole. And what different aspects you will have to take into account when selecting a light source and a driver.
I decided to write this as a case example so that the post is more concrete.

Most of the luminaire projects starts with the need for certain amount of lumen needed out from the luminaire. Then there can also be requirements for the shape and size for the light source. Color temperature, color rendering and lifetime expectancy might also be critical, but those are topics for a blog posts of their own.

LED Modules

LED Module

Case example

So in this case you have specified that the luminaire needs to achieve:

  • Lumen output 2000lm
  • Color Temperature 4000K
  • Ra(min)80
  • Lifetime 50 000 hours (LM70 for the whole luminaire)
  • Efficacy >120lm/W
  • Linear light source. Max length of 120cm

With these specifications, the finding of the suitable solution shouldn’t be a problem.
There are, however few things that have to be taken into account when looking at the data of LED modules:

  1. Lumen output: Some of the lumens from the light source will be lost due to the optics. The amount of lost lumens is around 10%. Therefore, you should look for light sources that can give you at least 10% more lumens than you need.
  2. The shape of the light source. Do you have a minimum size for the light emitting surface? The luminaire in this example can be built with modules around 30cm in length, but that would probably not be perfect fit your luminaire. It would leave a lot of empty space and the light distribution wouldn’t be even.

With those two in mind, you would need a light source that gives you roughly 2200lm and fills the whole 120cm evenly. That could be reached with for example 4 modules with lumen output of 550lm and length of 30cm or with two modules with 1000lm output and length of 60cm.

Selection of LED Drivers

Selection of LED Drivers

The Driver

For the case study presented above, you still have one more step to go: choosing a LED driver. Esko already wrote a good guide on this, so I’m going to be brief.

Before we can start, you have to specify one thing: How many LED modules do you want to drive with one LED driver? Only one module or several modules in series?

In this example you would probably want to drive all the modules with just one driver. This might be the case with all luminaires. In more complex lighting systems you might use several drivers. To find a suitable driver you will need to:

  1. Check the current that you want to drive your light source(or sources) with.
  2. Check the voltage of your light source (or sources) and check that it fits the driver’s voltage range.

You should always leave some room for the voltage as there might be some variations in the diodes. Check that the driver has around 10% lower minimum voltage and 10% higher maximum voltage than your light source.

So there you have it in brief. If you need more help or would like to leave a comment, please leave a comment or contact me!

You can also use our free tool to build your luminaire.

How to affect the lifetime of a LED module

How to affect the lifetime of a LED module

Lifetime of a LED module? What it means? Does it mean that LED module does not function anymore after the defined lifetime value? How to determine lifetime for the LED module? This post tries to explain what different lifetime estimation curves mean and how to interpret them.

Few terms have to be defined so that we can understand the lifetime for a LED module. First of all, the LED component itself, a tiny or a little bit bigger one, defines the lifetime of a LED module. Usually in normal conditions, all the other components last longer than the LED.

Some of the key parameters to evaluate LED module lifetime are listed below:

  • TC temperature = the temperature that can be measured from the LED module’s TC

This is usually placed so that it is as near to one of the diodes in the center part of the module as possible. This means as near LED component’s soldering pad on the PCB as possible.

LED Module, the point in the middle with the marking "TC" is the TC-point

LED Module, the point in the middle with the marking “TC” is the point where you measure the TC-temperature.

  • TJ temperature = the temperature of the PN-junction inside the LED diode.

This usually can’t be measured, but it can be calculated when the LED diode’s thermal resistance and the LED’s power consumption are known.

  • RTH = thermal resistance mentioned earlier. TJ = TC + RTH*PD, where PD is the power consumption of the LED diode.

Thermal resistance describes how well heat is transported out of the diode junction to soldering pad on the PCB. The smaller the thermal resistance value is, the better heat is transported away from the diode’s PN-junction.

  • LM or L = Lumen Maintenance.

LM value tells that how many percents of luminous output is still left from the original.

  • L80Bxx – the lumen maintenance lifetime

Bxx is a value at which xx% (e.g. 50%) of the products lumen output falls below 80% of the nominal initial value. If xx% is 50%, then it is expressed L80B50.

  • L80Fxx – the electrical failure time

Fxx is the value at which yy% (e.g. 10%) of the light source population has experienced conventional lights-out failure. If xx% is 10%, then 10% have experienced the catastrophic LED failure, other 90% of the LEDs continue lighting but at reduced lumen output level, was it then below or above 80% of the nominal initial value.

NB: It is very important to look at LED manufacturers’ lifetime estimates as some give the estimates as B values (for example B50) and some give the estimate as F values (for example F50).

Lifetime prediction for aLED Module at 700mA

Lifetime prediction for aLED Module at 700mA

How to design the LED module to have certain lumen output after certain operation time

There are few aspects that you should take into account when you want that your LED module operates more than expected operation time at the light output level that you, your customer or target application determines. If you for example require that after 50 000 operation hours of your LED module lumen output should be around 80% of the original lumen output value, you should consult your LED supplier. They will inform you the maximum TC temperature allowed for your LED component that this target will be reached. Or if your LED supplier gives lumen output curves versus operation time for certain TJ values, you should use the formula given earlier in the text to find out corresponding TC temperature.

When you find out the maximum TC temperature, there might still be some cases that you don’t reach the target lifetime. Then you should take some actions.

In the following there are some actions that you should think about if target hours are not reached:

  • Try using PCB with better heat conductivity.

Which PCB you have used? Is its thermal conductivity good enough to transport heat away from LED components that affect lifetime of the whole module? If you have used FR-4, why not to change it to Aluminum PCB.

  • Try adding larger heat sink or some other heat conducting elements.

Do you have effective heat sink under the PCB to conduct heat away from the PCB itself, not only from the LED components? Is there good thermal path from PCB to heat sink and have you used for example thermally conductive paste or tape?

  • Is there a way you could transfer the heat out from the inside of the luminaire?

Is your luminaire closed? Is there any way to transport heat away from the inner parts of the luminaire?

  • Think about separating light source and the power source.

The power supply also creates heat. Especially, if the luminaire is closed. Then it forms a closed system with two heat generating elements, the LED module and the LED driver. They both share the same heat load inside the luminaire, thus affecting each other.

Is there any means to divide the light source and the power supply, so that they are not in close contact with each other? Many times, if there is some kind of a metal profile into which the LED module is attached, the LED driver can be placed on the other side of the profile in order to avoid direct heat transfer between these two elements.

  • Can you leverage existing cooling solutions.

Ambient temperature(TA), affects the heat management of the luminaire.  Especially, if the luminaire is designed for application in some larger building, it can be possible to use for example building’s air conditioning system, to transfer heat away from the luminaire.

  • Can you change the driving current?

Of course, if you think the LED module itself as a single element and not as a part of a luminaire, also the driving current matters. Could you meet your lumen output requirements with smaller current during first years of operation? And when your light source’s lumen output starts to decrease in the course of years, is there a way to increase the driving current a little bit to reach the needed lumen output level after certain number of operating hours.

A table from aLED modules' datasheet. The typical current is 700mA, but you can drive it with as much as 1190mA. You can also drive it with much lower to save its lifetime.

A table from aLED modules’ datasheet. The typical current is 700mA, but you can drive it with as much as 1190mA. You can also drive it with much lower current (minimum in this case 70mA) to make its lifetime longer.

Those actions are some examples that you should consider to give your LED module required operation hours at certain lumen output level. Of course you should take the “big picture” into account: which kind of luminaire structure you have, which kind of driver you use and which kind of environment your luminaire is placed in.

Proper heat conduction and management are essential for long lifetime of your LED module! LED does not like heat.

If you have any comments or questions, you can post them in the comments.

What is aLED?

We released a new brand for our products; aLED. At first this brand is used along with our led modules, but later there will be more products to be labelled aLED.

There might be some people, possibly you, wondering what does aLED stand for? And why did we decide to create such a brand? Let me tell you.

aLED was formed during the spring and summer of 2014. There were many reasons behind the decision to create the brand and in this post I’m going open up those reasons.

Logo for the new aLED brand

Logo for the new aLED brand

  1. Warranty

We wanted to be able to give our customers a clear warranty. There can be many parties in the manufacturing process of a LED module. There is the PCB manufacturer, LED manufacturer, connector manufacturer etc. And all they give a different warranties and different conditions for those warranties. We wanted to give our customers a straightforward warranty:

aLED Module will last for at least 5 years. If it breaks while being used in a proper way before that, we will make it up to you.

  1. Delivery time

We got tired of the fact that the estimation of the delivery time for LED modules is guessing at best. PCBs are coming on one day, LEDs at another day and connectors on another. The company manufacturing the actual modules has time for production two months from now. We, and more importantly, our customers can never know when they get their products. We wanted to make this clear:

aLED Modules will be shipped in 48 hours after the purchase order.

aLED Module

aLED Module

  1. Variations in chromaticity

Our customers want to have guarantees that the module they order is actually near the right nominal color temperature. We have had these issues before and we know that everyone has had these issues. With the quality of the LEDs we use we can now guarantee the minimal variations in chromaticity.  So when you order your first module, all the following modules will have very little variation in chromaticity. To get an LED to exactly to a certain color temperature is near impossible, but we are working towards this.

  1. Right components

To be able to guarantee the quality of a LED module, all the components must be top quality. The modules are as good as the weakest link. We have taken a lot of time and effort to find the best possible components: the best PCBs, the best connectors, the best LED components and the best place to manufacture those modules.

  1. Customization possibilities

We know that our customers are different. For some the standard modules will be good enough and they can stand out with their luminaire design, price or some other factors. For some customers, the shape and type of the module is THE THING. That is the reason that we can offer customized modules to you. If you need soldered wires instead of connectors: you can have them. If you need customize shape with certain light distribution: you can have it. If you need anything else: you can have it. Delivery time might be a bit longer, but all the other guarantees still stand even for a customized module.

LED Module, which can be used in luminaire needing good light distribution.

Square shaped aLED Module.

  1. Best price

Everyone wants the perfect product for a perfect price. That’s what we have been aiming for. We have optimized the supply chain and negotiated good deals with component manufacturers. That is the reason we can offer you the best possible price.

These all might sound obvious, but they are not. We know that there has been problems and we have even had those problems ourselves. That is the main reason behind the aLED brand. We want to give you, our customers, a certain level of guarantee. We want to make the selection of LED module as safe and easy as possible.

Letter For Customers and Partners

Janne Mäkinen, Managing Director, Arrant-Light

Janne Mäkinen

I am very pleased to be writing this letter to our customers and partners – and to thank all of you who have trusted us over these past 30 years, helping us to sustain and grow the company.

The history of Arrant-Light Oy dates back 30 years to when my father, Tarmo Mäkinen, founded the company in 1984. The company initially focused on long-life fluorescent lamps and light bulbs, and very early on began offering a group replacement service for large companies. In the 1990s, the company expanded into supplying lighting components to luminaire manufacturers. Today, Arrant-Light Oy is a specialised supplier of lighting components, with LED components and related drivers, optics and accessories forming the largest product group. From the very beginning, the company has been driven by a principle of delivering best-in-class products that are easy to use and have a long service life.

Arrant-Light Oy currently delivers over 20,000 components a day to 11 countries and is the market leader in white LEDs in Scandinavia and the Baltic countries, with a more than 40% share of the market. Most of our customers benefit from a 24h delivery of stocked items.

With 30 years of experience under our belt, we are well placed to bring our customers the latest products with the highest efficacy. We engage in continuous research and development with our current suppliers and partners, and we will also be announcing the addition of new suppliers and interesting brands later this year.

To celebrate our 30 years in business, we decided to redesign our company logo. The new logo

Logo for the new aLED brand

Logo for the new aLED brand

will be followed by the introduction of aLED, the new brand name for Arrant-Light Oy’s own LED modules and other components. The aLED brand will also include a number of carefully selected products from our partners. aLED is a guarantee of quality and reliable delivery at a competitive price.
Our website at www.light.fi has also been given a makeover. The site is now even easier to navigate, and our aim is to increase the amount of easily available information on the site to make it a useful resource for professionals. Why not take a look at the new website!

I would again like to thank everyone for the past 30 years. I am confident that we can continue to provide You with the best service and products in the market. Development is an ongoing process.

Best wishes for autumn days filled with light,

Janne Mäkinen
janne.makinen@light.fi
Managing Director
Arrant-Light Oy

 

How to choose the right LED?

 

There are tons of different LEDs even in one manufacturer’s selection so how on earth can you find the right LED for your solution?

In my previous post I discussed about the basic characteristics and operation principles of LEDs. In this post I will discuss about different packages and about the facts that will probably have an impact on your selection.

I will divide LED light sources into three categories:

  • SMD LEDs
  • COB LEDs
  • LED Modules

I will now look more closely on these three categories before we jump into the actual selection.

SMD LEDs

SMD LED

Citizen CLL600 – Example of SMD LED

SMD LEDs are small diodes used in LED modules. They have to be assembled on printed circuit board (PCB). Generally they allow you to design any kind of luminaire and allow you to make uniform light source. On the downside, SMD LEDs always require them to be assembled on a PCB.

 

 

COB LEDs

COB LED

Citizen CLL052 – Example of COB LED

COB = chip-on-board. COB is a small package that combines many diodes as a one light source.  COBs have generally small dimensions and produce a lot of lumens. You can attach COB directly to the heat sink, which allows excellent heat management.  COBs don’t need a lot room in the luminaire fittings and are therefore well suited for luminaires with small room for light source.

LED Modules

LED-modules

Example of LED modules – Linear and rounded

LED Modules are made of SMD LEDs and PCB. LED distributors offer standard modules which in general are made for the common need. For example we have different sizes of linear modules as well as rounded modules. These modules have a certain lumen package which remains the same from LED generation to another. This enables lighting manufacturer to update their luminaires with more efficient LEDs. If you can’t find a suitable LED module for your application, you can always contact a manufacturer and ask them to design a custom module for you.

 

How to know where to start

The main thing that has an impact on your LED selection is, obviously, the type of luminaire you are manufacturing.  If you are transforming an old luminaire into an LED luminaire, then you will probably have some demands on the physical dimensions of LED.

For example, if you have a T5 or T8 fluorescent lamp, you will need a light source that

a) gives you linear light
b) gives you uniform light
c) fits in to the old luminaire’s body

If you are not restricted by physical dimensions, then you have a lot more options.  For example if you are building a whole new luminaire, the physical dimensions are not so critical. Or at least you get to decide what are the physical dimensions the LED needs to fit into.

COB Luminaire

Luminaire using Citizen COB LED

The other important criteria for LEDs is the amount of lumens you need. You might have an older luminaire that you need to replace, so ideally you would want as much light as the old one produces. So for example, if you have a 120cm fluorescent lamp and it produces 2700 lumen you will want a light source that:

a) fits into the 120 cm long body
b) gives you uniform and linear light
c) gives you  enough light (you won’t necessarily need 2000lm if you have better optical efficiency)

So in this example, you could use for example two modules that are less than 600mm in length and produce 1000lm each. Or you could use smaller modules, for example four modules that are less than 300mm in length and produce 500lm each.  As you may have noticed this selection does not give you the same amount of lumens from light source, but you will still get the same amount of lumens out of the luminaire.

Then there are obviously the color rendering index (CRI) and color temperature (CCT), both of which are mainly depending on the application of your luminaire. For example if you are building a luminaire for a clothing store or an art gallery, you will probably want as high color rendering as possible. On the other hand if you are manufacturing a street light, you probably won’t care about CRI so much.

If you need any help with selecting the LED, or if you disagree with any of my views, you can share your thoughts on the comments below.