LED GU5.3 Lamps Running Off SELV Transformers

[securespark]

I've not installed any new recessed lighting for around a decade and things move on.

I confess I have not kept my finger on the pulse of SELV and LED lighting.

The last time I was replacing lamps, LED stuff was in its earlier years.

I found some LED lamps worked as a direct replacement to a halogen GU5.3 MR16, while others refused to play ball.

Further down the timeline, the thinking was you could use LED lamps with these transformers as long as they were loaded up to the minimum loading.

But this is not easy to achieve in many cases.

Basically, I have some recessed lighting at my Mum's which I installed in 1991. Unbelievably, some of the original lamps are still going, along with all but one or possibly two of the original IBL and Mode Lighting transformers, which I replaced with Osram Halotronic.

I'm conscious that the old-school halogen lamps burn a lot of juice and a lot of that is wasted as heat.

Mum would rather not invest in new hardware, so I'm wondering if there is a reliable LED plug and play solution to cut the leccy bill?

 

[bernardgreen]

I'm conscious that the old-school halogen lamps burn a lot of juice and a lot of that is wasted as heat.

Is it really wasted ? In winter the heat from lighting does ( slightly ) reduce the gas bill.

My route when I am finally forced to use LED lighting will be based on the method used for LED strips

Three elements in a cluster and a suitable resister.

Dimming can be easily achieved by varying the DC voltage supplied to the cluster.

By under running the LED elements ( lower current through them ) increases the life of the elements. Running 12 Volt strips on 9 Volts still gives plenty of light and at the same time assures minimal migrations in the semiconductor structure of the LED elements.

 

[JohnD]

Is it really wasted ? In winter the heat from lighting does ( slightly ) reduce the gas bill.

at the expense of paying four of five times the price per kWh, and delivering it to the ceilings, whether or not you need it.

 

[securespark]

Yeah, this is heat that is ending in the loft and roof voids

 

[bernardgreen]

But some radiated heat does reach the skin. Even if it is 95% phycological the warm white light with a mild heating of the skin does have a good affect on the person.

 

[RF Lighting]

I’m not familiar with the transformers you mention. Are they wire wound or electronic? Is it set up with one transformer per light? Can the transformers be easily pulled through the downlighter holes?

 

[securespark]

A couple have one tranny per luminaire.

Most have one feeding two.

Yes, everything is accessible from below.

There is one of three types of tranny:

Mode Lighting

IBL (Intram Barwell Limited)

Osram Halotronic

 

[securespark]

There are some lights in the lounge using "old-fashioned" Thorn steel-cased toroidal trannies, but they're not part of this job.

 

[bernardgreen]

Nice to see the mention of the 2 metre limit on cable length.

 

[winston1]

A couple have one tranny per luminaire.

Most have one feeding two.

Yes, everything is accessible from below.

There is one of three types of tranny:

Mode Lighting

View attachment 232133


IBL (Intram Barwell Limited)

View attachment 232134


Osram HalotronicView attachment 232135

They are all switch mode supplies not suitable for LEDs.

1. LEDs don’t meet the minimum load requirement.
2. LEDs usually state 50/60Hz or DC. Those SMPS operate at 10s of KHz.

You need to get proper LED power supplies or a real (wire wound) transformer.

Even better replace with 240v GU10 LEDs.

 

[bsr]

Even better replace with 240v GU10 LEDs.

The obvious solution surely.

 

[securespark]

Done this with half of the lighting in the lounge. There are two rows of 4 down lighters.
The old Thorn wirewound transformer (there is one for each row) was a little too big to go through the hole (larger than a standard down light). Luckily, I found the tx was immediately adjacent to one of the holes. So I decided in my RA that it was better to cut away a little piece of plasterboard and remove the tx from below, rather than set up crawl boards and send number 2 son into a very tight loft space with double thickness insulation.

Will post some pictures when I go back later today.

 

[ericmark]

I removed from the skip, back in around 1998, some toroidal lighting transformers which I still have today. So not sure how far back they go, a shop refit, so likely late 80's. Not bad 40+ years old and still going strong. But the front loading video recorder and the development of the switched mode power supply has a lot to answer for.

The whole idea was the thicker the element in the quartz halogen lamp the longer it would last, so the 12 volt quartz lamp was born, the idea was also to have the quartz that hot the tungsten would not deposit on the quartz hence why quartz lamps should not be dimmed? so keeping the lamp at stop on voltage was an advantage, so a regulating power supply was a plus.

The higher the frequency the smaller the transformer, so mega hertz was also a plus, but there was a limit to the ratio on to off time, so often a minimum output, there are ways around this, but when the bulb was rated 50 watt why is switching off under 50 watt a problem?

The cold cathode MR16 had to be 230 volt, so until the LED there was no need for a transformer toroidal or electronic to supply less than 50 watt.

Philips did market a bulb it claimed would work with the minimum output transformer, but these seem to have gone. But the new generation of electronic transformer did go zero to rated output.

However we got bulbs clearly marked 50 Hz, as to if they could work on lower frequency I have never tested, they did seem to work on the kHz range of zero to rated output electronic transformers, but as to if at that frequency they became a radio transmitter I never tested. Neither did I try running them on DC.

There are DC 2" down lighters often rated 10 to 30 volt, far more expensive to the AC versions, which don't seem to want to run over 12 volt, as to if the DC output of a constant voltage so called driver is smooth enough for DC down lights also never tested.

I have played safe and used GU10 230 volt versions of the MR16 lamp, if we can call them MR16 as often missing the multifaceted reflector from which we get the MR from, the days of using a cathode ray tube from where we get the 16/8 of an inch from is well in the archives of history.

However the lighting industry seems to use rules of their own, with electronic ballasts, electronic transformers, two way switches, intermediate switches rather than reversing, and the list goes on, drivers when I started were current control devices, mainly found with AGL's (aircraft ground lights) so they all had same light output.

Even when I went back to school to do 'A' levels the diagram for the fluorescent light had the ballast missing, OMG as the Americans say, and this was advanced level, which seemed to be lower than ordinary level in my day. Even the CSE seems to be more advanced.

Showing my age, last in the school to do the Flintshire school leaving certificate, it was stopped as the CSE came in. Anyway I digress.