Category: All About Light

Sometimes people ask us about SAD light therapy lights. SAD means Seasonal Affective Disorder, which causes some people to become depressed during winter months when there is less natural light available.

SAD has been scientifically researched for many years. The consensus is that 10-30 minutes a day of exposure to artificial light with a sunlight-like spectrum can be helpful. And its preferable not to have UV (ultraviolet light) included in this spectrum. Easy enough with LEDs.

And how powerful should this light be in order to be effective? Research calls for about 10,000 lux.

And here’s the main problem: while virtually all SAD lights on the market say they make 10,000 lux, they don’t tell you how close the light has to be to give you that. Here’s why:

Lux depends on distance from the light. Lux is not the brightness of the light source (that’s lumens). To talk about lux without telling the distance from the light source is total nonsense.

Luckily, lux is easy to measure with an inexpensive meter. Based on some measurements we’ve done, on some of these lights you’d need to be as close as an inch or less away to receive 10,000 lux! That’s clearly not practical.

And this key information (distance) is omitted from most marketing. To be fair, we have seen a few more powerful lights which do specify the distance; some of the ones we’ve seen mention 12 – 14 inches. That’s uncomfortably close, and that’s the better ones.

The other issue is that it seems SAD lights work best from slightly above the eyeline – but most of what’s on the market is designed to sit on your desk or table, shining up at you. There are a few with stands that let you raise them higher, but not many.

If you’re in the market for a SAD light, choose one that tells you how close you need to be in order to get 10,000 lux. You might find they are a bit more expensive.

So, the natural next question is: well, Lumicrest, if you’re so smart, why don’t you make a better SAD light? We’ve considered this. But with the flood of inexpensive products all claiming to make “10,000 lux” (but maybe they’d need to be a couple inches from your head), it seems too hard to compete against all of that market noise. We could, but we don’t.

That being said, if you really want a custom SAD light solution that does what it’s supposed to, let us know …

The label on RGBWW LED strip says it consumes 24 watts per meter. That seems like a lot. Do I really need a 100 watt power supply to run just 4 meters of RGBWW LED strip?

First of all, what’s RGBWW mean? It stands for Red, Green, Blue, Cool White and Warm White. It allows you to mix any colour (and white) using a controller. Awesome!

If you turn on the Red, Green, Blue, Cool White and Warm White LEDs full power at the same time, the end result is simply WHITE! Because R, G and B together make white, plus two other white LEDs, you get powerful white.

And, when connected like this it uses 24 watts of power for every meter (39.3″) of LED strip. That’s what the label means when it says “24 watts per meter”.

BUT, the whole point of this kind of product is to mix any colour of the rainbow, not just to make blinding white – right?
It’s meant to be used together with a colour-controller with remote control or app in order to mix the colours.

So in that case, does it still use 24 watts per meter? Obviously not! For example, if only the Red light is on, it will use about 6 or 7 watts per meter. Same if only Green or Blue are turned on. Yellow is made with a mix of Red and Green (light uses “additive” colour mixing, it’s not the same as mixing paints). To keep the colours in balance, the controller will use only about 3 watts each of Red and 3 watts of Green to make yellow. This is so it doesn’t suddenly become twice as bright when you turn it yellow!

Now, you can also add some warm white and cool white to your colours in order to get a softer effect. These LEDs use about 5 watts per meter. Again if you mix warm and cool whites to get some “in-between” white, the output of these LEDs are balanced so you don’t suddenly get much more powerful light when two LEDs are mixed.

The net result is, the MOST power you can possibly draw when using a colour-controller is only 12 watts per meter, not 24 watts! Thus for a 5 meter (16.4 foot) roll of RGBWW LED strip you only need a power supply of 60 watts (12 watts x 5 meters)

Of course, you can use a higher capacity power supply, like 100 watts if you choose. No harm will be done (it won’t overdrive the LEDs). You’re just spending a bit extra money that you don’t need to, that’s all!

A simple question that’s surprisingly complex. Why? Because there are two answers, not just one.

If we’re talking about typical 110-120 volt AC wiring as commonly found in homes, shops, offices and so on, the black wire is “hot” and white wire is “neutral”. There is also a third wire, usually bare without its own insulation, which is a safety ground wire. These types of wires are found in BX and Romex /NMD90 cables. Without splitting too many hairs over terminology, that can roughly translate into black meaning “positive” and white meaning “negative”. Remember, we’re talking about AC (alternating current) here.

However, if we’re talking about DC circuits and electronics, quite often you’ll find a red white and a black wire. (Often, but not always …) In the world of DC electronics, the accepted wiring convention is that the red wire carries the positive voltage, and the black is circuit ground. Usually the red is marked as + (plus) and the black is marked as – (minus).

Notice that in both AC electricity and DC electronics, there is a black wire. But in AC electricity the black is hot (“positive”) whereas in DC electronics black is for negative.

Why? Because the worlds of AC power distribution and DC electronics developed somewhat independently, but the fact that both used black wires for different meanings was rarely an issue.

But now that low voltage LED lighting is commonplace, the question of “where to connect the black wire” has become confusing. Essentially, LEDs are a form of DC electronics – another name for LED lighting is SSL lighting, which means Solid State Lighting. As DC electronics, wires attached to LED devices usually (should) conform to DC wiring colour-code conventions.

The issue can arise when installing LEDs using an external power supply/driver, such as with LED strips (tape lights) and LED bars or even pendant lights. On the AC input to the power supply, you need to connect the hot/positive wire to the corresponding input of the power supply. But on the low voltage DC output side (12 – 24 V), the black wire means negative, and the red wire is hot/positive. If the power supply has terminals on the output side instead of coloured wires, the temptation would be to connect the black wire to the + (positive) terminal, and the red to the minus. But, LEDs being polarity-sensitive devices, the light won’t turn on! What’s more, there are even some special LED strips that can be damaged by reverse polarity connection.

AND NOW – we’ve noticed a rather disturbing trend of LED products coming out using white and black wires, with the black wire connected to positive. That’s really confusing. (China, I’m looking at you!) What’s going on?

My best guess is that there are some product engineers out there who want to “do it right” and so they go to trusty google (ok, it’s Baidu in China, as Google is blocked …) to find out what color the wires should be, and where they should be connected. And … they find some article that says black is positive/hot and white is neutral negative. But what’s missing is the fact that info is about AC WIRING only! It doesn’t apply to electronic devices like LEDs.

For LEDs, the red wire should be positive and the black wire negative. That’s it. Black wire should never carry positive in DC wiring. Got it?

Certification Labels

Class 2

Class 2 status means that a power supply will not deliver more power than it is rated to provide. For example, if you load a 90 watt Class 2 power supply with 200 watts of LED strip, the power supply will only put out 90 watts. Class 2 is important for safety and power supply longevity since the power supply can only give what it is rated to give and won’t burn itself out if over-driven.

Limited Power Source (LPS)

LPS and Class 2 are functionally equivalent. Both ensure that the power supply has a limited voltage and current output, for safety purposes. Because they are different certification standards, there is a lot of overlap in their definitions.

Double Insulation (Class II)

Class II and Class 2 often get confused, but they focus on very different aspects of power supplies. Class II designation means that the power supply relies not only on simple electrical insulation, but 2 layers (or a single reinforced layer) of insulation, and therefore does not require an earth ground connection. This is why on Class II power supplies, there is no ground pin on the input.

If you are new to lighting and find some of the terminology confusing, these videos help you demystify things.

David Geldart, President of Lumicrest, brings you a quick introduction to the most common types of lighting you’ll find in use today, including incandescent, fluorescent, halogen and of course, LED lighting.

 

Selecting the most appropriate lens beam angle can sometimes be confusing. When to choose a wide beam lens and when to choose a narrow beam lens? The video below helps you understand the differences and make the best choice.

What lens angle should I choose? This handy Beam Angle Calculator helps you determine the effect of different beam angles and different positions for your light fixtures.

Want to change the lens angle on a Lumicrest LED light? Watch this short video on how to swap the lenses on Lumicrest LED lights.

Still not sure? Contact us at 416.479.0132 or through our contact form and let us know what you’re trying to achieve. We’re glad to help!

What’s an “edison base”? A “GU10”? Learn about the different types of lamp bases in common use.

If you’re a professional and are thinking of upgrading the lighting at a museum or art gallery, you’ll want to read our LED Lighting for Museums and Galleries White Paper. Contact us to request a copy.

Lighting is a key factor in the comfort and aesthetics of every environment. Before LED lighting, you had to reduce the quality of your lighting in order to save energy. Compact fluorescent lights (CFLs) have been useful in reducing power consumption. However, CFLs’ harsh light, high UV emissions, non-dimmability, slow response, poor color rendering, and the environmental impact of their mercury content, mean they’re far from the ultimate answer.

Think that LED lights only produce the harsh blue tinted light like the first generation of LED Christmas lights? Not any more. Lumicrest’s LED lights produce a warm glare free light that is pleasing to the eye.

Environmentally Responsible
With Lumicrest’s LED products, now you can have clean, clear light directed exactly where you want it. Our lights contain no toxic mercury, unlike the common compact fluorescent bulb. They last over 25,000 hours, compared to 1,000 hours for an incandescent light bulb, 2,500 hours for a halogen light or 6,000 hours for a compact fluorescent. The absence of mercury in LED lights, avoids contamination of our landfills, and eliminates cleanup concerns when a fluorescent light is broken.

Big Energy Savings
Best of all, in a time of rising energy prices, you can save 80% or more on your lighting energy compared to halogen or incandescent lights. At first, you may be surprised at the initial cost of our LED lights. When you look closer, you understand how inexpensive they really are! Depending on how many hours per day your lights are on, your initial investment can pay itself back in a year or less, and you’ll save money for years to come.

Save on Bulb Replacement Costs Too
The energy savings alone make a compelling enough case for LED lighting – replacing a 50 watt halogen light with an 8 watt LED is a huge saving. However, when you factor in the long life of our LEDs, the picture gets even brighter. On average, you’d have to buy about 18 halogen lights during the life of a single Lumicrest LED light! The cost of replacement bulbs alone pays for the LED over its lifetime – AND you get huge energy savings as well.

Calculate the Benefits
Try our online LED Energy Savings Calculator and plug in the numbers and see for yourself. In commercial environments, you may have to pay outside labour to change your existing bulbs, so our calculator allows you to factor in the labour savings as well.

Reduce the Damage to Sensitive Works
Light rays (photons) cut through atoms of fragile color molecules and organic materials, breaking the bonds that hold the molecules together.
These images show the effect of long term exposure to UV on a 20th century oil paint. (images courtesy of the Canadian Conservation Institute)

When viewed in colour under an optical microscope, the upper image where the paint was unprotected shows the colours have faded, while the lower image shows the colours retained their original intensity when protected from UV.

The best preventative measure is to switch to a light source that does not emit UV nor unwanted heat from IR rays. Lumicrest’s LED lights emit no UV nor IR and can extend the life of light sensitive works by up to 5 times or more.

Contact Us
Call us today at 647.360.6475 to discuss how Lumicrest LEDs can improve your lighting and save you plenty of money on your energy costs.