LED dimming and Control

All phase controlled dimmers tregard;ess of circuit design or load need to be able to synchronize with the AC line and most importantly detect the AC Zero Crossing point. The reason why LEDs flicker when dimmed by conventional dimming technology is due to the dimmer trying to find the Zero Crossing which with LED technology is proving really challenging. There is a call internationally for Three wire electrical installations with an added neutral wire in the switch box to provide an essential return path for the dimmer.

Energy Management and home automation

A number problems arise when using a "dimmable" LED lamp with an incandescent dimmer, Typically a markedly reduced dimming range, preventing true ambiance settings. Constant flickering and depending on the level of dim ,can be a bright strobe like effect or just peripheral flutter causing immense discomfort. Inconsistency with some lamps firing up before others and Visa versa creating a disco type of effect, again totally unacceptable.
These phenomena's are posing some real challenges to lighting control systems and LED manufacturers. There is growing support and pressure on LED manufacturers to supply a product into the market that is more Dimmer tolerant and one that can be dimmed across the ranges by the majority of dimming technologies.

Energy Management and Lighting Control

While LED and CFL lamps are drawing market share from incandescent lamps due to their energy saving advantages, most consumers and end users require education about how these lamps will work with their existing dimming technology.
Dimmed lighting in itself is an energy saving process, dimming also allows for ambiance setting. 99% of the dimmers on the market allow for Incandescent dimming only.

LED Lighting Control and Dimming

Energy Efficiency requirements are forcing consumers to replace standard incandescent lamps with LED based technology. The big issue now is that most often the results are not what was expected, nor what was sold to them. There are performance issues which include actual light output, degree of light spread, colour variations, lamp failure and a BIG issue with dimming.

The Bottom line LED technology is NOT compatible with existing dimming technology. There are NO industry standards that guide performance requirements of Dimmers or LED's

Existing wiring infrastructure can negatively effect the capabilities of modern lighting controls. So retrofitting a home that has been fitted with an intelligent bus with Triac based dimming technology IS NOT AN OPTION.

It is also NOT A REQUIREMENT as the lighting control and automated system is in itself a massive contributor to reducing energy and far out performs the saving derived from lamp replacement.

As A consumer beginning a new build, rather invest in an energy management intelligent solution than on LED technology which in a residential application really has no ROI.

Automation and Lighting Control

Schneider Electric and Tridonic Announce Strategic Partnership

BY LIGHTING CONTROLS ASSOCIATION, ON MAY 9, 2012

Schneider Electric and Tridonic recently announced a strategic partnership. The corporate partnership represents collaboration around projects business, and will see the companies work together to promote energy efficient lighting control solutions to customers.

Schneider Electric operates in more than 100 countries and, through its diverse product and business portfolio, specialises in the design and implementation of lighting control systems. Tridonic, headquartered in Austria and part of the Zumtobel Group, enables customers around the world to develop innovative applications and solutions, through lighting components, lighting management systems, connection technology and LED solutions. Within the partnership there is a project with LEDON, a sister company of Tridonic, which develops and markets hi-tech LED retrofit lamps for private consumers.

The strategic partnership between the businesses will combine the product innovation and market pedigree from the companies to develop cutting-edge, energy efficient lighting control solutions for customers globally. The solutions will meet the needs of diverse market sectors, including airports, hospitals, infrastructure and high performance green buildings. Schneider Electric benefits from Tridonic’s deep know-how in electronic control gears as well as from the innovative Tridonic products. Tridonic benefits from Schneider Electric’s excellent customer relations in the project business where Tridonic takes the role as first choice partner for lighting management. In all cases customers will stand to benefit by receiving lighting systems with synchronised components from one hand and enjoying service and safe systems.

Home automation and Lighting Control

BY LIGHTING CONTROLS ASSOCIATION, ON JANUARY 4, 2012
by Jim Brodrick, Department of Energy

As more and more LED lighting products have come onto the market, one issue that has generated considerable confusion is dimmability. As discrete devices, LEDs are fully dimmable, and as a result the technology has long been touted as being more suitable for dimming than other lighting technologies. Many SSL products come with claims of dimmability, but in practice, many users have encountered problems when trying to dim them, resulting in no small degree of frustration. What’s more, LED sources exhibit other unfamiliar dimming behavior, as they typically do not lose efficacy or shift in color as much as incandescent sources do when they dim.

Why have there been dimming problems with LED lighting products? A big reason is that nearly the entire existing stock of dimmer controls – those already installed in residential, office, and commercial settings – was designed for incandescent lamps, and not for LEDs. That’s important, because the two technologies, in addition to being based on totally different principles, also interact with this installed base of controls quite differently. Electrically, an incandescent lamp is a simple resistor, whose light output is determined by the effective average of the voltage that feeds it, and responds predictably and consistently to the various circuitries used in traditional dimming controls. An LED lamp, on the other hand, consists of not only the chips, but also typically a driver. Separately, and especially together, they comprise something considerably more complicated than a simple resistor – something that is very much affected by nuances in circuit design used in traditional line-voltage dimming controls.

Making LED lighting products dimmable is not an easy task, and is further complicated by a lack of standards. For example, there are no performance standards for making dimmability claims about a product, and thus the term “dimmable” remains vague and undefined. This wasn’t much of a problem with incandescent lamps, which all behave pretty much the same way with dimmers. The National Electrical Manufacturers Association has formed multiple committees focused on improving LED dimming experiences. To date, they have produced an educational white paper, as well as guidance aimed at helping LED product developers improve their dimming compatibility with the installed base of dimmer controls. Additional efforts are still needed to define standard dimming performance evaluation and dimming compatibility testing.

Such efforts are sure to reduce dimming issues, but they likely won’t eliminate them. The bottom line is that successfully dimming an LED lighting product with a familiar line-voltage dimmer control depends on the driver and its compatibility with the dimmer and, for low-voltage circuits, the transformer, too.

The best way to know how or if a product will dim is to test it out – and this means the entire circuit, not just one lamp with one dimmer. That’s because there are minimum and maximum numbers of lamps that will work with a given dimmer, and this varies by the lamp and dimmer (and, for low-voltage systems, the transformer) combinations. But such testing is not always practical. To make it easier on buyers and specifiers, a number of manufacturers have started providing this kind of information in dimming compatibility tables for their SSL products, and the Lighting Facts® database will be adding links to such tables at some point in the near future. It should be noted that system variations can lead to performance variations, however, so even though a circuit with a specific combination of lamps and dimmer works today, if a different lamp (either a different make/model, or even a revision to an installed make/model) is swapped in for an existing lamp, all bets may be off.

Although dimming problems persist, and many product dimming claims are still unreliable, the prospects for dimming LED lighting are much better today than they were even a year ago – and will continue to improve. Not only are dimmable LED sources available, but new dimmers are also hitting the market. The new approaches to dimming may eliminate many compatibility concerns entirely. But for now, at least, successful dimming depends on buyers and users being well-informed and exercising due diligence.

African Power Generation

Angola’s Kambambe hydroelectric dam to operate from October 2012


The Kambambe dam
Luanda, Angola --- ESI-AFRICA.COM --- 14 October 2011 - It’s been announced that the Kambambe hydroelectric dam, located in Kwanza Norte province of Angola, and with a total installed capacity of 180 megawatts (MW), will start its operation in full from October 2012.

This information has been released here by the administrator of production of the National Electricity Company, José Carlos Neves, during a morning programme on Radio Nacional de Angola (RNA).

The Kambambe Dam, according to Neves, is benefiting from rehabilitation and modernisation of two units, involving the replacement of major instruments of supervision and control of the venture, which had previously reduced its production by 50% of installed capacity.

He stressed that the project aims to ensure greater operational capability and availability of the project, and confirmed that completion was scheduled for October next year.

“With full operation of the hydroelectric dam the power supply to Luanda and other regions of the country will be improved,” he said.