Tag Archives: LED technology

Driven by the Light

MAIN-DRIVER
For some unaccountable reason – when LED lighting arrived – we all had to refrain from calling power supply units ‘transformers’ and refer to them as ‘drivers’. The source of these terminological decisions remains unknown – but it is highly effective at spreading confusion amongst us mere mortals in the design community.

DRIVER1Unfortunately the ‘driver’ is too important a component to ignore. The rather anonymous black box is an essential piece of kit and it can actually be quite exciting – or is that stretching the point too far – let’s see? All I would say is that you ignore a little knowledge about drivers – at your peril…
The two main types of driver we commonly use are ‘constant current’ and DC versions and you must choose which one is relevant for the intended application.

Constant current LEDs are ‘driven’ at a current that effects their output. If you are supplied a 700ma driver with your LED fitting – that is the level of current tested for the published output data.

DRIVER4V3TIP: Did you know that if you find a LED fitting is too bright you can effectively dim by lowering the output of the fitting by reducing the amount of current it receives from the driver (that is what dimming does) so you could swap to a 350ma driver instead.

So far so good – it still remains a small box connected to the fitting – so what is exciting?

New LED products are arriving with integral drivers – radically reduced in size and on-board – so soon you might not have to worry about little black boxes at all!

A word of caution – we know that LEDs last an age but the weakest link in many LED systems it is the driver and not the LED and the fitting itself. Simply put – a 10 degree increase in temperature can halve the life of the electronics. So the thermal dynamics of an on-board driver or one that sits on top of a fitting have to be well designed, so be vigilant and buy the best available.

So the hunt is on for a driver-less mains powered LED chip – of which Samsung (to name one) has achieved by creating an AC chip. Its early days as there is some flicker generated from the 50 hz mains power but watch this space.

Still waiting for the exciting bit?

shop-lightPhilips have developed a driver that transmits a unique identifying code in the light emitted from the fitting it’s powering. Invisible to us humans but not to a smart phone or a tablet – an app will triangulate your position within the building and follow your every move. The illustration depicts an intelligent shop lighting system where the drivers guide shoppers to their favorite bargains! A bit Big Brother for my liking…

If you need advice on drivers to suit your application – that are reliable and compatible – just call us and we will be happy to help!

How many people does it take to change an LED Light Bulb?

Maintenance-man

If there is a subject destined to bore the typical reader of this newsletter rigid – its likely to be a conversation about maintenance costs? After all – I don’t see many financial managers amongst our circulation list. However, in my view the benefits arising from the installation of LEDs in terms of lower maintenance costs is an important issue and one which you should keep at least half an eye open to!

detail_mini_tilt_rotate_image_01Saving your customers money opens opportunities for you

Increasingly we are asked to justify the  cost of LED refurbishments. The good  news is that LED as a technology is easily  accountable and delivers savings that  earlier lighting technology failed to  achieve. Yet the reduction in the cost of    the upkeep of a building – is oftenoverlooked. In effect we hold the key to introducing our customers to a real return in investment over and above the benefits of energy savings.

Is this really our role as designers?

It’s surprising to me that although on the whole most understand that installing and replacing existing lighting with an LED source will offer a lower consumption in energy – many forget that this coupled with saving hundreds of man hours in maintaining light fittings – changing lamps – is a powerful tool in increasing the profitability to a business. The issue of maintenance is not solely for a commercial property – it effects us all.

4 factors your customers need to know
phillips

1. LED has long lamp and fixture life – 15,000 hours (fluorescent territory) to 50,000 hours. The amount of regular checking and physical changing of fittings is greatly reduced.

2. Capital investment is quickly returned – refurbishment projects are easily paying for themselves in 6 months and this time period is further reduced when maintenance savings are included.

3. Business disruption decreased – If we take a retail business or a premises with day-time public access – the cost of night shift maintenance can be astronomic! Maintaining an existing halogen scheme can cost two electricians and a ladder £900 multiplied by three visits per annum.

4. LED is an intelligent technology – Modern controls systems report back the status of a fitting and can predict failure rate by knowing the number of hours spent.

lens2A final word on aesthetics. LED and lower maintenance allows us to approach the challenge of high ceilings and areas of awkward access with renewed creative inspiration. This is especially the case in older spaces and interiors where many options have been constrained in the interest of work-access. I personally delight in the use of LED strips and miniaturised spotlights on beams and within alcoves and niches.

We have many fixtures available that offer ingenious solutions to LED refurbishments and a great deal of practical advice on the development of innovative lighting schemes that have low maintenance built in.

Call us on 01279 812350 or click here for more information.

LED has a bad case of Gremlin

Gremlin-LED
LED technology offers huge promise but we shouldn’t be blinded by its potential. In service to my customers I have to remain vigilant on LED’s shortcomings. In this instance a flaw has appeared which requires the attention of all those currently specifying LED lighting installations which use control systems.


It would seem reasonable to assume that LEDs draw less power from a circuit. After all down-lights and strips require a fraction of the wattage needed by conventional tungsten halogen lamps. For instance, if you take a typical restaurant, you may have a 5 amp lighting circuit that delivers 1150w. Using older technology halogen lights you would be comfortable deploying about 20 units across the same circuit. Surely, given that LED lights relatively ‘sip’ power of at least 80% less compared to their – you are permitted to assume that you can pepper the ceiling with downlights wherever you fancy? But you could be making a costly mistake.
The simple fact is that making this once safe calculation on capacity is no longer valid! It is likely that when the lights are switched on that they will flicker or will fail leading to a total revision of the lighting design – pulling the assets and refitting. It is the designers worst nightmare and it is happening all the time.
Why?
In truth we receive conflicting information from lamp, driver or luminaire manufacturer’s and even the makers of control systems aren’t 100% sure yet how many lamps or luminaires will work without testing. In electrical terms it is due to the capacitance of the LEDs that leads to this need to de-rate a circuit. After some investigation it seems that a power spike is commonly caused across the dimmer channel which requires a 90% reserve in capacity. So when controlling with a digital dimming system, effectively the power saving that is delivered by LED lights is thrown away in wasted unused capacity in the expensive dimmer channel.
To remain safe, controls suppliers are issuing a blanket de-rating of 90% – so only 10% of the channel can be used regardless of whether LED lamps or luminaires are being used – where there is some evidence that it’s only relevant LED lamps and not luminaires with their own drivers.
How to avoid the problem?
The prospect of decommissioning and re-commissioning a lighting installation is a nightmare for designers and clients alike. How do you avoid the mistake in this modern age where dimming and control systems are widely demanded?
The simply truth is that with no definitive advice available from suppliers you have to test the load as a practical simulation. At Orange Lighting we have quite literally constructed a circuit in our offices to test the control system and the LED lamps or fittings before we can design the system / lighting circuits. After we are sure that one dimmer channel on a rack is functioning we are confident to roll out the complete system.
We are happy to share this knowledge too. If you have a project that needs a combination of LED and control with dimming – call us and we will be happy to offer a solution.