Dimmable LED lighting system?

[dhutch]

Normal wiring and then use smart lighting such as Philipps Hue. No hums, buzzing or flickering.

Fair. Philipps hue seems to be cornering that market at the moment, it's not ruddy cheap though is it. Each unit is ok, but if you already have a house full of lamps your like it's a lot more than a set of Pearl BC halogens and a MK dimmer!

I'm using Aurora Enlite dimmable LED GU10 lamps with Fibaro dimmers and having no problems at all - they dim perfectly from 100% to 1% - no hum, no flicker.

I've also got some cheapish (from Amazon) dimmable LED E14 filament lamps with Fibaro dimmers, which work reasonably well, although they do start to flicker a bit when they get below about 10%.

Ok thanks, good information. I am aware I'm less tolerant than some of noise, but specific brand suggestions are good if the pairing matters.

Daniel

 

[^woody^]

Fair. Philipps hue seems to be cornering that market at the moment, it's not ruddy cheap though is it. Each unit is ok, but if you already have a house full of lamps your like it's a lot more than a set of Pearl BC halogens and a MK dimmer!

If cost is an issue have a look at the Tradfri range from Ikea. These are the cheapest smart bulb range at the moment and have good functionality similar to Hue. Again no noise or flicker.

The other good thing with choosing smart bulbs is the automation that comes with it - timers and PIR switching

 

[flameport]

Is 1-10V or 0-10V really overpriced, overcomplex etc, and, after all these years, really on the verge of disappearing?

The basic principles are not - but if all you want is dimming then you may as well fit a normal dimmer.

By the time they have been packaged up into a control system by a manufacturer, they most certainly are overpriced and complex, because they are not just a simple dimmer - all kinds of other useless stuff is added, such as linking to other equipment, panels which can control things from other rooms, multiple saved lighting scenes and all the other useless functions which no one uses after the first day.

Having seen several installations where the latest and greatest stuff was installed when the building was constructed, now 5 / 10 / 15 years later, the parts are failing. Spares cannot be obtained any more, the manufacturer (if they still exist) now makes a whole range of totally incompatible stuff, and because all of the wiring to the switches twisted pair, Cat5 or similar and goes back to a central control cabinet, it's not even possible to replace with normal wiring without ripping the walls and ceilings apart. Or add extra lights / switches without massive disruption.
Domintell being top of that list of fails, but are certainly not the only culprits.

0-10 systems are not problem free either, as different drivers from different manufacturers may not work in exactly the same way, so with multiple lights in a single room, dimming all of them with one control may result in some dimming more than others, or some turning off before others do. Even if they are all the same today, at some point one or more will need to be replaced.

 

[JohnW2]

Have I been misunderstanding the meaning of the word "Input" for umpteen decades?

 

[bernardgreen]

The first mains voltage dimmer I built was a motor driven Variac transformer with, if memory serves me right, two 60 watt lamps. It was just too big to be sensible.

 

[dhutch]

So what kit am I looking at for a 1-10v system, I've done some googling and found bits buy nothing obviously or clear.

Secondly it appears there is a decent chance my reasonable new mk dimmers is leading edge and the my Phillips dimmable bulb would prefer trailing edge. But also that I may well not be able to run 10 lamps off one dimmer anyway.

Daniel

 

[dhutch]

Anyone?


I was talking to be dad at the weekend, for their house he has found some LED lamps that have multiple levels of dimming achieved by cycling the power switch.

Phillips do one that has a few levels followed by the lowest level which uses extra-warm, these remember the level and come back on at the same level they where last on each time till you cycle it round again.

Then another brand which I don't recall, which where I think cheaper, and come on full brightness each time unless you power cycle them at the instance which I think often is what you would actually want assuming the lamps where not hugely over spec'ed to start.


Daniel

 

[SimonH2]

When an LED is dimmed the colour remains the same

Actually not true - but it depends on how the dimming is done.

so there is no ambiance like with tungsten

That is true.
If the current is reduced, most LEDs change colour to some extent. That is one reason why dimming is more normally done by pulse width modulation (PWM) - switching the LED between off and full normal current rapidly. Many driver circuits also use PWM for the basic current regulation - adjusting the on-off ratio to give the desired average current. That's why you can often see strobing effects from LEDs.

LED lamps are best dimmed by controlling the current driven through the LED element in the lamp. This is best achieved by a smoothed DC current source feeding the LED element.

As above, few "quality" systems do this because it alters the colour slightly.

If only it were that simple in real life

All LED lamps have some form of driver as part of the lamp and this driver controls the current through the lamp. NOT to be confused with an "LED DRIVER" external to the lamp which converts mains to maybe 12 votls to supply a 12 volt LED lamp. That external "LED DRIVER" is a power supply and not a driver.

You are missing out the constant current LED lamps used in many "professional grade" systems. The driver for those is constant current, typically 350mA, and the lamps are connected in series up to the capacity of the driver.

 

[SimonH2]

BTW - there are systems appearing now that use ethernet (specifically via TCP/IP) for control, and PoE for power. I think a few outfits are doing them, but I know Ubiquiti has one in testing.
In principle this means running a network cable to each "switch" position and each light position - going back to a PoE capable network switch. As usual, each vendor has their own proprietary system though I believe Ubiquiti has plans for gateways to established building control systems (because they are initially aiming at the commercial lighting market).

A little light reading ...
https://www.cibsejournal.com/general/taking-control-approaches-to-power-over-ethernet-in-lighting/
https://www.igor-tech.com/news-and-...s-lighting-install-to-save-80-in-energy-costs

And then there is an established digital bus system to replace the old analogue methods ...
https://en.wikipedia.org/wiki/Digital_Addressable_Lighting_Interface
https://www.buildings.com/article-details/articleid/1463/title/dali-explained

 

[JohnW2]

BTW - there are systems appearing now that use ethernet (specifically via TCP/IP) for control, and PoE for power. I think a few outfits are doing them, but I know Ubiquiti has one in testing. In principle this means running a network cable to each "switch" position and each light position - going back to a PoE capable network switch.

I would be surprised if that were not the case!

Although the absolute levels of power loss/'wastage' are probably very low with LEDs, any system of lighting which involves distribution of the power at ELV will presumably result in fairly poor reliability (in terms of power supplied vs. power delivered to load), particularly when using conductors with such modest CSAs as in CAT5/6 ?

Kind Regards, John

 

[SimonH2]

Yes, my first reaction was to think about the cable losses. But some case studies say that there's power savings - mostly I believe from more efficient power conversions. Whether this includes the power conversions in the network switch isn't stated in the ones I've read.
The opportunities it opens up are interesting to say the least - in principle the capabilities would only be limited by your imagination. I always fancied outside lights where "sensor A lights lamps 1&2, sensor B lights lamps 2&3, ..." or even going as far as "if sensor B triggered after sensor A, then turn on lights 1&2&3" and "if sensor A triggered after sensor B then turn on lights 1&2". I think you probably get the idea - not having to walk into a dark zone before you trigger another PIR light to see where you're going.

 

[JohnW2]

Yes, my first reaction was to think about the cable losses. But some case studies say that there's power savings - mostly I believe from more efficient power conversions. Whether this includes the power conversions in the network switch isn't stated in the ones I've read.

Maybe, but one is invoking two stages of potential losses (in addition to the cable losses) - firstly conversion from 230V to the 48V or whatever of the PoE, and then 'conversion' of that to the voltage or currenmt required by the LED.

As for the cable losses themselves (i.e. assuming zero 'conversion losses'), distributing at, say, 48V rather than 230V would result in something like 4.8 times the current, hence about 23 times the power loss in a cable of the same CSA, or probably in excess of 100 times the power loss if one were comparing CAT5/6 (I think ~0.2mm² CSA) with, say, 1mm² T+E.

The opportunities it opens up are interesting to say the least - in principle the capabilities would only be limited by your imagination. I always fancied outside lights where "sensor A lights lamps 1&2, sensor B lights lamps 2&3, ..." or even going as far as "if sensor B triggered after sensor A, then turn on lights 1&2&3" and "if sensor A triggered after sensor B then turn on lights 1&2". I think you probably get the idea - not having to walk into a dark zone before you trigger another PIR light to see where you're going.

Yes, as with any sort oif 'automation', the opportunities for 'playing' would be endless, but probably more by way of gimmicks than truly 'useful' (let alone actually 'needed') functionality!

Kind Regards, John

 

[rsgaz]

I think ~0.2mm² CSA

PoE uses two conductors for positive and two conductors for negative, so 0.41mm² for any calculations/comparisons.

And Cat6 is thicker(23AWG), 0.26mm² for one conductor.

 

[JohnW2]

PoE uses two conductors for positive and two conductors for negative, so 0.41mm² for any calculations/comparisons.

Fair enough - so 'only' around 50 times the 'power loss/wastage' with 48V/Cat5 as compared with 230V/1mm² !

And Cat6 is thicker(23AWG), 0.26mm² for one conductor.

Maybe down to 40 times with Cat6, then

Kind Regards, John

 

[ericmark]

My son read about all the advances in central heating, and how running a LAN outlet to the TRV head would allow one to control each room individually. He installed a server in the loft and LAN outlets by each radiator. However when he came to install the TRV heads he found they were nearly all wifi, there were some made for underfloor heating which were hard wired, but these were near double the price to wifi models.

I will guess we will find the same with lighting, it seems already manufacturers are using something similar to the 5-20 mA industrial control system, bulbs tend to sink the first few mA to heat so there is enough current through the bulbs to work switches without the need for a neutral at the switch.

The problem is when there is a power cut, all these switches default to off, fair enough in the bedroom, but not in corridors. These switches really need the installer to be able to set the default.