Five ways LED drivers impact architectural lighting

Lighting can have the single most impact on the aesthetic of a space. While it functions primarily to illuminate spaces indoors, it plays a critical part in the beauty of building design. And in modern building engineering, it also is the focus of energy efficiency strategies. These aspects challenge architects to provide the functional lighting requirements dictated by specifications, architectural design that meets the building owner’s wants, and also lighting with the smallest impact on energy consumption. LED lighting is almost always the answer, and drivers create a wide variety of styles that allow designers to marry design wants with the functional needs of a building. To get the most from LED lighting, architects should understand how LED drivers effect it and how to use that to their advantage.

Consistent Output

While LEDs are low voltage light sources, once they are connected in series the voltage increases. Changes in voltage can cause a disproportionate current which can cause the light output to vary. This can be a problem when designing a lighting scheme. This is why the driver is so important. LED drivers are the power supply for LEDs and operate much like a ballast for fluorescent lights. They regulate the current and can protect the LEDs from line-voltage fluctuations.

Dimming Control

Dimming is a feature used by many designers to create an ambiance in spaces like theatres and restaurants. But traditional dimming has had issues with fluctuations and loss in efficiency. With the use of a driver, LEDs can dim from 100 percent to 0 percent output. There is no loss of efficiency as the LEDs use the same voltage and current during dimming that they do during full output. Using drivers for LED dimming controls can also lengthen the life span of LEDs because dimming can reduce the operating temperatures.

Color Sequencing

LEDs are also great for architectural designs that require color changing and sequencing. Drivers can allow dimming for various color LEDs to create a coloring and lighting effect. The drivers can also work with a sequencer which receives the voltage output and converts it to a three channel output in red, green, and blue that can then make an array of color combinations.

 Flexibility in Design

Drivers for LEDs can be constant voltage or constant current types. They can also be customized for individual LED fixtures or for an array. You can also find drivers that adapt to most types of LED lighting. There are drivers to fit any lighting situation, freeing the designer from the constraints of typical lighting power supplies. Drivers are small enough to fit inside of junction boxes, so they never have to be incorporated into the design.

Energy Efficiency

Perhaps one of the biggest selling points of LEDs is for energy efficiency. With lower thermal energy produced and longer lifespans, the energy savings are easily calculated. But energy-efficient lighting design also should incorporate ways to reduce usage altogether. These means lighting schedules and shut off times in unoccupied areas. Drivers work easily with occupancy sensors, lighting controls, dimmers and automation systems. With these tools, a lighting design can be created to shut off lights in every building space if unoccupied for a set period of time. They can also shut off entire areas or whole building lights at certain times with controls and automation systems. These can create huge energy savings for the entire building.

Lighting is fundamental to any building design. The right lighting system can be as inviting as it is functional, and with drivers they can also save the building owner money. While LEDs are the standard in lighting efficiency, it’s their drivers that enable them to adapt to any design and provide constant, efficient lighting. They’re small, convertible, and often interchangeable. Whether you’re designing signage for an opera house or lighting for a university library, drivers are the efficient and easy way to achieve the lighting design you want.

LED Lighting 101

Development of LED Lighting

Over a hundred years ago, in 1907, an English engineer Henry J. Round noticed that when a 10V potential is applied to silicon carbide crystal, it emits yellowish light. Twenty years later, Oleg Vladimirovich Losev was first to further investigate the phenomenon and published a paper “Luminous carborundum detector and detection effect and oscillations with crystals“. After that, there was no real progress for almost half a century. The first light emitting diode was developed by Nick Holonyak Jr., from GE.  It was about the size of a piece of pepper. His invention became the red LED that was used for indicator lights. The final part of RGB LED development that occurred in 1993, was creating blue light, resulting in the ability to produce any color of the LED light. The inventor Shuji Nakamura enabled the development of white LED lights that are now installed in commercial and manufacturing spaces all over the world. At first, LEDs were highly expensive and were only used in laboratory equipment but over time, as technology evolved, prices dropped and the application of LED lighting has widely spread.

LED Lighting Basics

LED lighting is solid state lighting (SSL) and that is the main differentiation point between LEDs and other forms of lightings such as incandescent and fluorescent. SSL means that semiconductor light-emitting diodes are the source of illumination as opposed to gas or electrical filaments found in standard lighting. LED is a p-n junction that emits light when activated. Electrons recombine with electron holes in a device and release photons once current is applied. This is called electroluminescence. Similar to incandescent lamps, LEDs achieve full brightness without warm-up and frequent turning on and off doesn’t affect their productivity. LEDs emit light in one direction and thus exclude the need for reflectors or diffusers. Another great feature of LED lights is that they produce an insignificant amount of heat. Other than that, LED sources are dimmable and can be integrated with various sensors and controls. This enables additional power savings because they can operate depending on occupancy of a room and with use of daylight saving.

LED Bulbs

After years of development, LED companies have finally introduced a replacement for wide-spread 60 watt light bulb in 2009. Traditional incandescent bulbs measure brightness in watts, meaning you had to buy a bulb with higher wattage in order to get more light. LED bulbs measure brightness in lumens which is a more precise measure. The difference in energy consumption is radical. For example, LED equivalent of a 60-watt bulb consumes between 9 and 12 watts while providing the same brightness and a 40-watt equivalent LED bulb consumes only 6 to 8.5 watts. That is roughly 5 times less energy needed for the same effect. Furthermore, LED bulbs have an almost unlimited lifespan and they will continue to light up even after the estimated lifespan expires but the brightness may drop. They sometimes have lifetime expectation up to 100,000 hours of operation, meaning, if you leave your LED bulb on for 8 hours a day, twenty years will pass before you have to replace it. One of the important features of LED lighting is that they’re eco-friendly. LEDs don’t contain toxic materials and they’re recyclable.

Compared to standard light bulbs, LEDs:

  • Emit more lumens,
  • Do not emit UV lights,
  • Are more durable,
  • Have a longer lifespan,
  • Are smaller in size,
  • Consume less energy,
  • Do not contain Mercury or any other toxic gases.

LED Products

As we already know, there are many LED products and the number continues to grow. Continuous improvement of LED lighting products leads to lower prices and wider adaptation of the technology. Most common LEDs include:

  1. Industrial and commercial lighting – found in parking lots, garage lighting, street lights, outdoor lighting, refrigerator lighting, etc.
  2. Kitchen lighting – used under cabinets for lighting kitchen countertops,
  3. Recessed lighting – commonly used in households and offices,
  4. Replacement lights – for replacing old incandescent light bulbs,
  5. Holiday lights – much cheaper and easier to use than standard holiday fixtures.

 

How do LED Drivers Work

What is an LED driver

LED lighting has proven to be more effective compared to incandescent or fluorescent lights, due to their high efficiency and long lifespan. Even though they are becoming more popular and are suitable for many applications, from households to horticultural lighting, many people are still unaware of how do they work. Just like any other technological innovation, they need something to drive them, and that’s an LED driver.

LED driver is a device that provides power to light bulbs. Since LEDs need DC current to operate, and the current flowing in households as well as in power lines is AC, the driver converts the current to DC and provides it to the bulbs. However, LED drivers are not solely providers of the current, they also act as the protection to the bulb itself.

How do LED drivers work

There are three types of drivers: constant current, constant voltage, and constant current/constant voltage drivers. They are meant for different situations. It is important to make sure they’re used properly since they do not provide the same thing.

Constant current drivers are applied for LEDs that need constant current and different amount of voltage within a fixture. This is not a common situation in LEDs since most of them require 12V to operate. Constant current drivers are used when the lamps don’t have the current resistor already installed. The type of LEDs that require current driver are supposed to be supplied by a specified current usually displayed in milliamps (mA) or amps (A). Higher current makes the LED brighter but in case it’s not regulated, it can consume more current which further leads to excess current that shortens the life of an LED. By applying the constant current driver, LEDs are supplied by constant current and maintain brightness and efficiency.

Constant voltage drivers are used when a light assembly needs stable voltage since the current is usually already managed inside the lamp or an assembly. These LEDs require one stable voltage and maximum output power, so the driver provides either 12V DC or 24V DC. This is usually specified on the light itself. The type of power which is typically found in our homes is 120-277VAC. Constant voltage drivers switch the alternating current voltage to low direct current voltage and maintain it for proper operation of the LED.

Constant current/constant voltage drivers feature both options, just like their name suggests. They run as constant voltage but they switch to constant current in case when output current passes the rated limit. Constant current/constant voltage drivers are used in applications where flexibility is required.

Does your LED driver need water/dust protection?

If an LED driver is installed in a place where it may come in contact with water or dust, it needs to be properly protected. Just like any electrical enclosure, it can come with a rated IP protection (Ingress Protection – used to define levels of sealing effectiveness against intrusion from foreign bodies and moisture). IP number usually consists of 2 digits, first one represents solid objects and second one represents liquids. So, if you are looking for a driver that can come in contact with water and dust, you can use an IP65 driver.

Here’s a list of definitions:

Solid Liquid
0 No protection No protection
1 Protection against solid objects >50mm Protection against water droplets
2 Protection against solid objects >12.5mm Protection against water droplets at a 15° angle
3 Protection against solid objects >2.5mm Protection against water spray at 60° angle
4 Protection against solid objects >1mm Protection against water spray at any angle
5 Dust protected Protection against water jets from any angle
6 Dust tight Protection against powerful jets
7 Protection against temporary submersion up to 1m
8 Protection against submersion in water over 1m

Life expectancy of an LED driver

All drivers have MTBF, or mean time before failure, and in order to maximize their lifespan and decrease maintenance costs, it’s best to run the LED driver at recommended outputs.

What lies ahead for LED drivers

LED lights and drivers are one of the most developing technologies today. US Department of Energy estimates that LED efficiency will reach 258 lumens per watt by 2020, or, 2.5 times more than standard fluorescent lamps. This will result in about 90% power savings. By then, the prices will drop thus making LED lights available to more households. One of the key points in the technology in the rise are LED drivers but many are unaware of their importance. Other than driving power to the bulbs, they are essential in providing a vast range of lightning designs. Each lighting solution needs a driver design, and the drivers themselves provide saving, ambience and definition to lighting installations. And last, drivers are the one responsible for efficiency and durability of LEDs.