Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Not Answered
  • Locked Locked
  • Replies 6 replies
  • Subscribers 9 subscribers
  • Views 256 views
  • Users 0 members are here
Options
You may also be interested in
This discussion is locked.
You cannot post a reply to this discussion. If you have a question start a new discussion

LED lighting in domestic applications (again)

David Howard
Hello All,


This is my first posting so please be gentle with me.  I read one of the threads some time ago about the problems with LED lighting in either the home or small offices. One of the issues evident with LEDs, as already mentioned elsewhere is that the transformer rectifier circuits have to be built into each and every light fitting. While the LEDs themselves may last 10k or 20k hours, the control circuits certainly do not ( based on personal experience of LED lighting in my own home).


I got to thinking about how the LED fittings could be made more robust in order to achieve the claimed lifespan and also how new builds or retrofitting could make use of the energy saving potential better. There are many disadvantages of having a DC network in the traditional sense to power lights, switches would burn out quickly, lights would fail due to spikes when being energised are examples. What I thought was, why not split the switching circuit from the lighting circuit? What if we were to use a touchpad with a wireless transmitter instead of a light switch? This could be powered by the nearest mains point, have a unique network address and by association, control the lights in that area. So we have a means of controlling the lights, now to power them. Why not have a control unit that contains a transformer rectifier  and powers the individual lighting circuits all spurred off the control unit. The control unit would receive on/off commands from the light switch and using solid state relays, energise the relevant circuit. Alternatively, there could be a number of control units located around the home/office controlling a smaller number of light circuits. The LED light fittings themselves could then be of much simpler construction, reducing cost and prolonging their life. The control units would be more robust than the cheap components found in current LED lights thereby improving reliability.


Does my idea above seem feasible? This would work best in new builds but could be retro fitted relatively easily.


Kind regards


David Howard MIET
Parents
  • 0
    The problem is not that there are systems that seperate LEDs and their AC-DC conversion (drivers) it is that there is no standardisation between them, and they need to be bought as a matched pair, so you can't easliy do what you envisage.

    Ideally agreeing on say 48, 24 or 12V +/- 10% ,  and all LED fittings then are aranged into strings of dies and has enough series R to sort itself out on that voltage, would be great. This is not what has happened, we have several constant current standards, several constant voltage standards, and it is all a mess. And then the layout is all wrong, and we may not really want light fittings at all in the conventional sense.

    I suspect a standard or 2 will emerge, but it will be like the USB phone charger standard, arriving after about a decade of total confusion has caused pain and loss to early adopters.

    Currently in in terms of reliabilty of lamps with inbuilt supply, some of the best lamps I have seen are the ones with no electronics beyond a series capacitor,  a bridge rectifier, and then very long strings of LEDs of 100V  or so and a bit of some current limiting. They are also good in terms of EMC emissions, as there are no supersonic square waves with edges in the hundred nanosecond time scale.
Reply
  • 0
    The problem is not that there are systems that seperate LEDs and their AC-DC conversion (drivers) it is that there is no standardisation between them, and they need to be bought as a matched pair, so you can't easliy do what you envisage.

    Ideally agreeing on say 48, 24 or 12V +/- 10% ,  and all LED fittings then are aranged into strings of dies and has enough series R to sort itself out on that voltage, would be great. This is not what has happened, we have several constant current standards, several constant voltage standards, and it is all a mess. And then the layout is all wrong, and we may not really want light fittings at all in the conventional sense.

    I suspect a standard or 2 will emerge, but it will be like the USB phone charger standard, arriving after about a decade of total confusion has caused pain and loss to early adopters.

    Currently in in terms of reliabilty of lamps with inbuilt supply, some of the best lamps I have seen are the ones with no electronics beyond a series capacitor,  a bridge rectifier, and then very long strings of LEDs of 100V  or so and a bit of some current limiting. They are also good in terms of EMC emissions, as there are no supersonic square waves with edges in the hundred nanosecond time scale.
Children
No Data

Join us to get the best from IET EngX.

Joining EngX lets you personalise your experience so you stay up to date on the topics that interest you, plus you’ll be able to make connections who are looking to collaborate, exchange ideas and more.

Join us Not now

Community Rules & Guidelines