The shops seem to be full of LED lamps, all of a sudden.

They don't seem to be very bright though. There still doesn't seem to be
anything that's a drop-in substitute for an old 100W or 120W
incandescent bulb.

How long before they catch up?

Daniele

D.M. Procida wrote:
The shops seem to be full of LED lamps, all of a sudden.

They don't seem to be very bright though. There still doesn't seem to be
anything that's a drop-in substitute for an old 100W or 120W
incandescent bulb.

How long before they catch up?

Daniele

Hang in there. I think they are pushing towards 50W equivalent already.


--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

On 22/10/2012 19:02, D.M. Procida wrote:
The shops seem to be full of LED lamps, all of a sudden.

They don't seem to be very bright though. There still doesn't seem to be
anything that's a drop-in substitute for an old 100W or 120W
incandescent bulb.

How long before they catch up?

Daniele

Well, they first of all have to sell the generation you are describing -
not there in brightness, less than excellent colour, odd light patterns,
uncertain life, etc. Leave that as the best available for as long as
they can.

Then they introduce the next generation which improves one or two of
these - but leaves the rest of the deficiencies (or, if they are really
lucky, introduces new deficiencies we have even thought of). And sell
them for as long as they can.

And so on...

So a few generations to go...

--
Rod

On Mon, 22 Oct 2012 19:02:45 +0100, D.M. Procida wrote:

The shops seem to be full of LED lamps, all of a sudden.

Yes there does seem to be more on the shelves and a wider range of types
than only a few months ago.

They don't seem to be very bright though.

This is true and at least they have a lumen rating on the packaging. What
I am going to have to do is make a note of what a real 60W tungsten perl
or 40W clear candle puts out before they disappear. I have a "feel" for
they amount of light they produce but 120lm doesn't mean a lot.

--
Cheers
Dave.

On 22/10/2012 19:20, The Natural Philosopher wrote:
D.M. Procida wrote:
The shops seem to be full of LED lamps, all of a sudden.

They don't seem to be very bright though. There still doesn't seem to be
anything that's a drop-in substitute for an old 100W or 120W
incandescent bulb.

How long before they catch up?

Daniele

Hang in there. I think they are pushing towards 50W equivalent already.

I just took delivery of one of these:

http://www.amazon.co.uk/gp/product/B006IIA59Y

Used alongside other 50W 12V halogens, its comparable in brightness and
beam coverage (from 10' up anyway). The colour temperature is close, but
very slightly higher (note I am comparing with LV halogens that are
whiter than 240V GU10s anyway). The only obvious downsides are its not
quite as pretty in the fitting (bulb aesthetics itself, and also lack of
dichroic colour spill onto the surfaces behind the lamp). Also the light
still has that slightly CFL quality to it. Not a problem when mixed in
with other real lamps though.

With GLS format lamps the slight problem seems to be they only use half
the bulb envelope as a light emitter - great for cap up apps, but not as
good for cap down on side mount.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Mon, 22 Oct 2012 19:02:45 +0100,
(D.M. Procida) wrote:

The shops seem to be full of LED lamps, all of a sudden.

They don't seem to be very bright though. There still doesn't seem to be
anything that's a drop-in substitute for an old 100W or 120W
incandescent bulb.

How long before they catch up?

50 years, possibly never.


--

On 22/10/2012 19:02, D.M. Procida wrote:
The shops seem to be full of LED lamps, all of a sudden.

They don't seem to be very bright though. There still doesn't seem to be
anything that's a drop-in substitute for an old 100W or 120W
incandescent bulb.

How long before they catch up?

I was just about to post a question on a similar theme, so I may as well
hijack yours ;-)

I just took delivery of one of these:

http://www.amazon.co.uk/gp/product/B006IIA59Y

Used alongside other 50W 12V halogens, its comparable in brightness and
beam coverage (from 10' up anyway). The colour temperature is close, but
very slightly higher (note I am comparing with LV halogens that are
whiter than 240V GU10s anyway). The only obvious downsides are its not
quite as pretty in the fitting (bulb aesthetics itself, and also lack of
dichroic colour spill onto the surfaces behind the lamp). Also the light
still has that slightly CFL quality to it - but its certainly not the
cold blue of some "white" LEDs. Not a problem when mixed in with other
real lamps anyway.




--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Monday, 22 October 2012 19:02:47 UTC+1, D.M. Procida wrote:
The shops seem to be full of LED lamps, all of a sudden.



They don't seem to be very bright though. There still doesn't seem to be

anything that's a drop-in substitute for an old 100W or 120W

incandescent bulb.



How long before they catch up?



Daniele

I've just installed 4 led down-lighters in a small bathroom...very happy so far.
My first advice? Go for low voltage ones - watt per watt 12v led gives more light (more efficient) and a more pleasant white than the high voltage bulbs - I wouldn't buy the "warm white" because these are less efficient than "cool white" (3w cool white is brighter than 4w warm white) - if in need of a warmer hue then I'd just use the "cool white" and a shade/filter over it..
There is a negative point...the colors are a bit uneven - this is more evident where less leds are involved - the bulbs in the the bathrooms have 3 leds (1 watt each giving a total of 3 watt per bulb) - the central area of the spotlight has a bluish/washed tint while the rest looks "normal" (difficult to explain really, I've never noticed this problem with other types of bulbs)...the multi-led high voltage bulb I used in the past (cylinder shape with lots of leds on it) gave an ugly bluish light but uniform color. Still, I prefer the new low voltage bulbs - very pleasant mostly-white light, very well suited for bathrooms and kitchens (no way back to hot halogens/incandescent or slow fluorescent bulbs).

On 22/10/2012 19:02, D.M. Procida wrote:
The shops seem to be full of LED lamps, all of a sudden.

They don't seem to be very bright though. There still doesn't seem to be
anything that's a drop-in substitute for an old 100W or 120W
incandescent bulb.

How long before they catch up?

Daniele


The only issue that some need to improve on is the effective colour
temperature, but that is not always a true reflection on the colour you get.

In other aspects the are way ahead
more efficient
longer lasting

The colour issue is highly subjective and is manufacturer dependent but
a major issue for most people. I tend to buy very specific high power
LEDs for specialised applications so do not get to see too much cheap
and nasty chinese crap.
Some of the suppliers are offering 90W devices, delivering about 15Watts
of optical power. These are exceptionally bright-but cost about 200
quid each right now :=p . ...OK maybe the costs need to improve a little
too.
There are now specific safety standards for LEDs, parallels to laser
safety classifications, due to the intensity that they are capable of
delivering

How long before people can really understand the specifications, and
more importantly how long before there are decent standards that the
sales and marketing division cannot take the **** over. Well that is
getting there too.

David

On 22/10/2012 23:14, David wrote:
On 22/10/2012 19:02, D.M. Procida wrote:
The shops seem to be full of LED lamps, all of a sudden.

They don't seem to be very bright though. There still doesn't seem to be
anything that's a drop-in substitute for an old 100W or 120W
incandescent bulb.

How long before they catch up?

Daniele


The only issue that some need to improve on is the effective colour
temperature, but that is not always a true reflection on the colour you
get.

In other aspects the are way ahead
more efficient
longer lasting

The colour issue is highly subjective and is manufacturer dependent but
a major issue for most people. I tend to buy very specific high power
LEDs for specialised applications so do not get to see too much cheap
and nasty chinese crap.
Some of the suppliers are offering 90W devices, delivering about 15Watts
of optical power. These are exceptionally bright-but cost about 200
quid each right now :=p . ...OK maybe the costs need to improve a little
too.
There are now specific safety standards for LEDs, parallels to laser
safety classifications, due to the intensity that they are capable of
delivering

How long before people can really understand the specifications, and
more importantly how long before there are decent standards that the
sales and marketing division cannot take the **** over. Well that is
getting there too.

David

I've replaced a few halogen spotlights with LEDs and am pleased with the
results. However, the 2 lamps I put into our cooker hood had to be taken
out again - after a short warming-up period they started to flash off
and on. The retailer tells me that the 12v transformer in the hood needs
around 10w resistance to work properly and that the only solution is to
replace the transformer with a LED driver. Not possible without
dismantling the hood - SWMBO won't hear of that and it would be a big
job now all the tiles, etc are in place. So I'll stick with the halogens.

John M

On 23/10/2012 01:26, John Miller wrote:
On 22/10/2012 23:14, David wrote:
On 22/10/2012 19:02, D.M. Procida wrote:
The shops seem to be full of LED lamps, all of a sudden.

They don't seem to be very bright though. There still doesn't seem to be
anything that's a drop-in substitute for an old 100W or 120W
incandescent bulb.

How long before they catch up?

Daniele


The only issue that some need to improve on is the effective colour
temperature, but that is not always a true reflection on the colour you
get.

In other aspects the are way ahead
more efficient
longer lasting

The colour issue is highly subjective and is manufacturer dependent but
a major issue for most people. I tend to buy very specific high power
LEDs for specialised applications so do not get to see too much cheap
and nasty chinese crap.
Some of the suppliers are offering 90W devices, delivering about 15Watts
of optical power. These are exceptionally bright-but cost about 200
quid each right now :=p . ...OK maybe the costs need to improve a little
too.
There are now specific safety standards for LEDs, parallels to laser
safety classifications, due to the intensity that they are capable of
delivering

How long before people can really understand the specifications, and
more importantly how long before there are decent standards that the
sales and marketing division cannot take the **** over. Well that is
getting there too.

David

I've replaced a few halogen spotlights with LEDs and am pleased with the
results. However, the 2 lamps I put into our cooker hood had to be taken
out again - after a short warming-up period they started to flash off
and on. The retailer tells me that the 12v transformer in the hood needs
around 10w resistance to work properly and that the only solution is to
replace the transformer with a LED driver. Not possible without
dismantling the hood - SWMBO won't hear of that and it would be a big
job now all the tiles, etc are in place. So I'll stick with the halogens.

Sometimes a solution is new bulbs, but with one old style one in the mix
to provide the minimum load. You still get a reduction in power, and
better colour rendition as a free side effect.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

wrote:

I've just installed 4 led down-lighters in a small bathroom...very happy so far.
My first advice? Go for low voltage ones - watt per watt 12v led gives more light (more efficient) and a more pleasant white than the high voltage bulbs

Would you care to explain that a bit more? Aren't the actual LEDs
identical, it is just the production of a suitable voltage for
them that differs between LV and mains lamps. Do you mean that
this conversion loss lowers efficiency?

Chris
--
Chris J Dixon Nottingham UK


Have dancing shoes, will ceilidh.

On Mon, 22 Oct 2012 19:26:03 +0100, polygonum wrote:

On 22/10/2012 19:02, D.M. Procida wrote:
The shops seem to be full of LED lamps, all of a sudden.

They don't seem to be very bright though. There still doesn't seem to be
anything that's a drop-in substitute for an old 100W or 120W
incandescent bulb.

How long before they catch up?

Daniele

Well, they first of all have to sell the generation you are describing -
not there in brightness, less than excellent colour, odd light patterns,
uncertain life, etc. Leave that as the best available for as long as
they can.

Then they introduce the next generation which improves one or two of
these - but leaves the rest of the deficiencies (or, if they are really
lucky, introduces new deficiencies we have even thought of). And sell
them for as long as they can.

And so on...

So a few generations to go...

Oh, you cynic! Bit like selling us flatter, squarer TVs just before
widescreen came out, or pushing standard kettles for a few years after jug
kettles were feasible.
Luckily, I was a bit slow at school and found that by the time the teacher
had made a mistake and then the other pupils had noted the corrections I'd
missed the error and so 'caught up' - this has been useful for most of my
life, enabling me to miss all sorts of crap and let others make the mistakes
:-)
--
Peter.
The gods will stay away
whilst religions hold sway

Well seems to me that we are in the area where they are just making bigger
and bigger ones from the small ones. I wonder why nobody can make a large
size led, there has to be a reason, maybe heat dissipation or something.

Brian

--
From the Sofa of Brian Gaff Reply address is active
"D.M. Procida" wrote in
message
...
The shops seem to be full of LED lamps, all of a sudden.

They don't seem to be very bright though. There still doesn't seem to be
anything that's a drop-in substitute for an old 100W or 120W
incandescent bulb.

How long before they catch up?

Daniele

"D.M. Procida" wrote in
message
...
The shops seem to be full of LED lamps, all of a sudden.

They don't seem to be very bright though. There still doesn't seem to be
anything that's a drop-in substitute for an old 100W or 120W
incandescent bulb.

How long before they catch up?

Daniele

I have recently bought some 9w (3 x3watt) LEDs as a replacement for 50w
GU10 Halogens. Putting one in a fitting of four bulbs for comparison it was
easily as bright as the other 3. I went for 'warm white'.

mark

On Tuesday, 23 October 2012 06:58:59 UTC+1, Chris J Dixon wrote:
swimmydeepo wrote:

I've just installed 4 led down-lighters in a small bathroom...very happy so far.

My first advice? Go for low voltage ones - watt per watt 12v led gives more light (more efficient) and a more pleasant white than the high voltage bulbs

Would you care to explain that a bit more? Aren't the actual LEDs
identical, it is just the production of a suitable voltage for
them that differs between LV and mains lamps. Do you mean that
this conversion loss lowers efficiency?

I think swimmydeepo's statement comes about from the lower voltage LEDs ability to share the LED driver. Having one driver for lots of low voltage LEDs is probably more efficient than having one driver per LED.

Running an LED at a lower current is more efficient if you can arrange that.. The graph of light output versus current is a curve which is steeper at lower currents. Running several LEDs at low current is more efficient than running a single LED at high current.

dan.

On Monday, 22 October 2012 19:02:47 UTC+1, D.M. Procida wrote:
The shops seem to be full of LED lamps, all of a sudden.

Yes, they're expensive and they're months behind what's possible.

If you want the leading edge, easily, buy direct from China via eBay. You won't see anything BC bayonet cap, but ES, SES & GU10 are now cheap and good.. GU10s in particular are a very good replacement. I'm using some with 60 domed LEDs for general downlighter use and 60 square surface-mounts for shop spotlighting. Having this many LEDs means that there's no driver required, or making heat. The 108 LEDs 'corncobs' are a good replacement for GLS bulbs too. Good colours and plenty bright. Prices are £3 - £5 and upwards

My first advice? Go for low voltage ones - watt per watt 12v led gives more light (more efficient) and a more pleasant white than the high voltage bulbs

The colour temperature is unrelated to the driver voltage.

- I wouldn't buy the "warm white" because these are less efficient than "cool white" (3w cool white is brighter than 4w warm white) - if in need of a warmer hue then I'd just use the "cool white" and a shade/filter over it.

Sticking a shade or filter over a cool colour is going to reduces its efficiency too!

There is a negative point...the colors are a bit uneven - this is more evident where less leds are involved.

Get better quality LEDs in binned versions. For example, Cree sell EasyWhite LEDs which are binned to specific colour temperatures, where the bins are also different sizes (i.e., the closer you want your LED to be to a particular colour temperature, the more you pay). I have EasyWhite MCEs in my kitchen (3500K) and there is no noticeable difference in colour or light output between them.

dan.

On Tuesday, 23 October 2012 08:43:34 UTC+1, Brian Gaff wrote:
Well seems to me that we are in the area where they are just making bigger
and bigger ones from the small ones. I wonder why nobody can make a large
size led, there has to be a reason, maybe heat dissipation or something.

Why should they? Stacking up small dice is just easier. Even the large square arrays with an overall yellow resin cover are 9 or 16 dice underneath.

If you get to 60+ LEDs, you can also run them directly at mains voltage, in series strings. This avoids the cost and waste heat of a driver.

On 23/10/2012 10:34, Andy Dingley wrote:
On Monday, 22 October 2012 19:02:47 UTC+1, D.M. Procida wrote:
The shops seem to be full of LED lamps, all of a sudden.

Yes, they're expensive and they're months behind what's possible.

If you want the leading edge, easily, buy direct from China via eBay. You won't see anything BC bayonet cap, but ES, SES & GU10 are now cheap and good.. GU10s in particular are a very good replacement. I'm using some with 60 domed LEDs for general downlighter use and 60 square surface-mounts for shop spotlighting. Having this many LEDs means that there's no driver required, or making heat. The 108 LEDs 'corncobs' are a good replacement for GLS bulbs too. Good colours and plenty bright. Prices are £3 - £5 and upwards

Do you have any specific recommendations for suppliers/models?

--
Rod

On 23/10/2012 10:49, polygonum wrote:
On 23/10/2012 10:34, Andy Dingley wrote:
On Monday, 22 October 2012 19:02:47 UTC+1, D.M. Procida wrote:
The shops seem to be full of LED lamps, all of a sudden.

Yes, they're expensive and they're months behind what's possible.

If you want the leading edge, easily, buy direct from China via eBay.
You won't see anything BC bayonet cap, but ES, SES & GU10 are now
cheap and good.. GU10s in particular are a very good replacement. I'm
using some with 60 domed LEDs for general downlighter use and 60
square surface-mounts for shop spotlighting. Having this many LEDs
means that there's no driver required, or making heat. The 108 LEDs
'corncobs' are a good replacement for GLS bulbs too. Good colours and
plenty bright. Prices are £3 - £5 and upwards

Do you have any specific recommendations for suppliers/models?

And what do they mean by "Pure white"? Am happy to assume that warm
white is around 2700 and cold white might be 6000-6500. Does that leave
pure white at 3500-4000? Or have I taken a step too far in my
assumptions/guesses?

--
Rod

On Oct 23, 8:43*am, "Brian Gaff" wrote:
Well seems to me that we are in the area where they are just making bigger
and bigger ones from the small ones. I wonder why nobody can make a large
size led, there has to be a reason, maybe heat dissipation or something.


LED`s are light emitting sandwiches, with the filling emitting the
light.

Means making extra large LEDs dosen`t gain much in output, it would be
trapped in the middle.

Cheers
Adam



Brian

--
From the Sofa of Brian Gaff Reply address is *active
"D.M. Procida" wrote in
...







The shops seem to be full of LED lamps, all of a sudden.

They don't seem to be very bright though. There still doesn't seem to be
anything that's a drop-in substitute for an old 100W or 120W
incandescent bulb.

How long before they catch up?

Daniele

Andy Dingley wrote:

If you get to 60+ LEDs, you can also run them directly at mains voltage, in series strings. This avoids the cost and waste heat of a driver.

Presumably there are sharing resistors, arranged so that a single
device going open circuit doesn't kill the whole string?

Chris
--
Chris J Dixon Nottingham UK


Have dancing shoes, will ceilidh.

In article , wrote:
On Tuesday, 23 October 2012 06:58:59 UTC+1, Chris J Dixon wrote:
swimmydeepo wrote:

I've just installed 4 led down-lighters in a small bathroom...very happy so far.

My first advice? Go for low voltage ones - watt per watt 12v led gives more light (more efficient) and a more pleasant white than the high voltage bulbs

Would you care to explain that a bit more? Aren't the actual LEDs
identical, it is just the production of a suitable voltage for
them that differs between LV and mains lamps. Do you mean that
this conversion loss lowers efficiency?

I think swimmydeepo's statement comes about from the lower voltage LEDs ability to share the LED driver. Having one driver for lots of low voltage LEDs is probably more efficient than having one driver per LED.

Especially one driver per LED that has to be squeezed into the "bulb".

I don't see how it affects the colour though. Both 12v and 240v are available
in a range of colour temperatures, but the same LED ought to give the same
white at the same power, regardless of the driver efficiency.

On 23/10/2012 12:56, Alan Braggins wrote:
In article , wrote:
On Tuesday, 23 October 2012 06:58:59 UTC+1, Chris J Dixon wrote:
swimmydeepo wrote:

I've just installed 4 led down-lighters in a small bathroom...very happy so far.

My first advice? Go for low voltage ones - watt per watt 12v led gives more light (more efficient) and a more pleasant white than the high voltage bulbs

Would you care to explain that a bit more? Aren't the actual LEDs
identical, it is just the production of a suitable voltage for
them that differs between LV and mains lamps. Do you mean that
this conversion loss lowers efficiency?

I think swimmydeepo's statement comes about from the lower voltage LEDs ability to share the LED driver. Having one driver for lots of low voltage LEDs is probably more efficient than having one driver per LED.

Especially one driver per LED that has to be squeezed into the "bulb".

I don't see how it affects the colour though. Both 12v and 240v are available
in a range of colour temperatures, but the same LED ought to give the same
white at the same power, regardless of the driver efficiency.

Yup, I think that is confusing issues that apply to halogen (where LV
are "whiter"), but not LED


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 23/10/2012 01:26, John Miller wrote:
On 22/10/2012 23:14, David wrote:
On 22/10/2012 19:02, D.M. Procida wrote:
The shops seem to be full of LED lamps, all of a sudden.

They don't seem to be very bright though. There still doesn't seem to be
anything that's a drop-in substitute for an old 100W or 120W
incandescent bulb.

How long before they catch up?

Daniele


The only issue that some need to improve on is the effective colour
temperature, but that is not always a true reflection on the colour you
get.

In other aspects the are way ahead
more efficient
longer lasting

The colour issue is highly subjective and is manufacturer dependent but
a major issue for most people. I tend to buy very specific high power
LEDs for specialised applications so do not get to see too much cheap
and nasty chinese crap.
Some of the suppliers are offering 90W devices, delivering about 15Watts
of optical power. These are exceptionally bright-but cost about 200
quid each right now :=p . ...OK maybe the costs need to improve a little
too.
There are now specific safety standards for LEDs, parallels to laser
safety classifications, due to the intensity that they are capable of
delivering

How long before people can really understand the specifications, and
more importantly how long before there are decent standards that the
sales and marketing division cannot take the **** over. Well that is
getting there too.

David

I've replaced a few halogen spotlights with LEDs and am pleased with the
results. However, the 2 lamps I put into our cooker hood had to be taken
out again - after a short warming-up period they started to flash off
and on. The retailer tells me that the 12v transformer in the hood needs
around 10w resistance to work properly and that the only solution is to
replace the transformer with a LED driver. Not possible without
dismantling the hood - SWMBO won't hear of that and it would be a big
job now all the tiles, etc are in place. So I'll stick with the halogens.

John M

Heat is the big killer for LEDs and leads to a serious drop in
performance or death so I'd be careful in any application where there
may be an additional heat source

Most LED failure are down to poor thermal management.

On Tuesday, 23 October 2012 10:24:02 UTC+1, wrote:
On Tuesday, 23 October 2012 06:58:59 UTC+1, Chris J Dixon wrote:

swimmydeepo wrote:



I've just installed 4 led down-lighters in a small bathroom...very happy so far.



My first advice? Go for low voltage ones - watt per watt 12v led gives more light (more efficient) and a more pleasant white than the high voltage bulbs



Would you care to explain that a bit more? Aren't the actual LEDs

identical, it is just the production of a suitable voltage for

them that differs between LV and mains lamps. Do you mean that

this conversion loss lowers efficiency?



I think swimmydeepo's statement comes about from the lower voltage LEDs ability to share the LED driver. Having one driver for lots of low voltage LEDs is probably more efficient than having one driver per LED.



Running an LED at a lower current is more efficient if you can arrange that. The graph of light output versus current is a curve which is steeper at lower currents. Running several LEDs at low current is more efficient than running a single LED at high current.



dan.

not really...the driver might play a part too but I'm talking of simple comparison side by side between 2 identical 3 watt bulbs (same manufacturer - CREE), the only difference being that one is a MR16 low voltage and the other is a GU10 high voltage - the difference in the quality and the quantity of light emitted by the two is quite noticeable...I have compared other types and makes and the only constant results is that low voltage offer more light and a more pleasant white. Then, we must consider that the low voltage driver takes a bit away from that efficiency but it is very negligible.

On Tuesday, 23 October 2012 20:28:19 UTC+1, John Rumm wrote:
On 23/10/2012 12:56, Alan Braggins wrote:

In article , wrote:

On Tuesday, 23 October 2012 06:58:59 UTC+1, Chris J Dixon wrote:

swimmydeepo wrote:



I've just installed 4 led down-lighters in a small bathroom...very happy so far.



My first advice? Go for low voltage ones - watt per watt 12v led gives more light (more efficient) and a more pleasant white than the high voltage bulbs



Would you care to explain that a bit more? Aren't the actual LEDs

identical, it is just the production of a suitable voltage for

them that differs between LV and mains lamps. Do you mean that

this conversion loss lowers efficiency?



I think swimmydeepo's statement comes about from the lower voltage LEDs ability to share the LED driver. Having one driver for lots of low voltage LEDs is probably more efficient than having one driver per LED.



Especially one driver per LED that has to be squeezed into the "bulb".



I don't see how it affects the colour though. Both 12v and 240v are available

in a range of colour temperatures, but the same LED ought to give the same

white at the same power, regardless of the driver efficiency.



Yup, I think that is confusing issues that apply to halogen (where LV

are "whiter"), but not LED


"but not LED"?!
Have you first hand experience or are you just assuming things? Try out by yourself and tell me....
Then, maybe, the secret is really in the driver or the fact that these 12v led bulbs runs on low voltage just like the halogen 12v - both are more efficient and more pleasant than the high voltage counterparts just because these are low voltage (what about that?).

On 23/10/2012 22:45, wrote:

"but not LED"?! Have you first hand experience or are you just
assuming things? Try out by yourself and tell me.... Then, maybe, the
secret is really in the driver or the fact that these 12v led bulbs
runs on low voltage just like the halogen 12v - both are more
efficient and more pleasant than the high voltage counterparts just
because these are low voltage (what about that?).

It seems to me that there is implicit in that the assumption that the
voltage that the actual LED receives differs. Do you believe that to be
so? Do you have any evidence that is so?

In the case of 12 V halogens you know that they are being supplied with
12 V - through some sort of transformer (whether traditional or
electronic) and the filaments are very different to those intened for
mains usage.

But with LEDs you are most likely not seeing the voltage that the actual
Ds receive. Only what you are supplying to the complete device.

--
Rod

polygonum wrote:
On 23/10/2012 22:45, wrote:

"but not LED"?! Have you first hand experience or are you just
assuming things? Try out by yourself and tell me.... Then, maybe, the
secret is really in the driver or the fact that these 12v led bulbs
runs on low voltage just like the halogen 12v - both are more
efficient and more pleasant than the high voltage counterparts just
because these are low voltage (what about that?).

It seems to me that there is implicit in that the assumption that the
voltage that the actual LED receives differs. Do you believe that to be
so? Do you have any evidence that is so?

In the case of 12 V halogens you know that they are being supplied with
12 V - through some sort of transformer (whether traditional or
electronic) and the filaments are very different to those intened for
mains usage.

But with LEDs you are most likely not seeing the voltage that the actual
Ds receive. Only what you are supplying to the complete device.

Forward voltage on a LED is between IIRC 3v for red and up to 5V for white.

At highish powers

http://en.wikipedia.org/wiki/LED_circuit is worth a look


--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

On Tuesday, 23 October 2012 10:35:28 UTC+1, wrote:
My first advice? Go for low voltage ones - watt per watt 12v led gives more light (more efficient) and a more pleasant white than the high voltage bulbs



The colour temperature is unrelated to the driver voltage.



- I wouldn't buy the "warm white" because these are less efficient than "cool white" (3w cool white is brighter than 4w warm white) - if in need of a warmer hue then I'd just use the "cool white" and a shade/filter over it.

The Natural Philosopher wrote:
polygonum wrote:
On 23/10/2012 22:58, The Natural Philosopher wrote:
polygonum wrote:
On 23/10/2012 22:45, wrote:

"but not LED"?! Have you first hand experience or are you just
assuming things? Try out by yourself and tell me.... Then, maybe, the
secret is really in the driver or the fact that these 12v led bulbs
runs on low voltage just like the halogen 12v - both are more
efficient and more pleasant than the high voltage counterparts just
because these are low voltage (what about that?).

It seems to me that there is implicit in that the assumption that the
voltage that the actual LED receives differs. Do you believe that to
be so? Do you have any evidence that is so?

In the case of 12 V halogens you know that they are being supplied
with 12 V - through some sort of transformer (whether traditional or
electronic) and the filaments are very different to those intened for
mains usage.

But with LEDs you are most likely not seeing the voltage that the
actual Ds receive. Only what you are supplying to the complete device.

Forward voltage on a LED is between IIRC 3v for red and up to 5V for
white.

At highish powers

http://en.wikipedia.org/wiki/LED_circuit is worth a look


Precisely. So what difference inherent to the mains vs low voltage
distinction would make efficiency or colour differ - if you look at
the individual LED elements - rather than the entire package? I can't
see any. Because the LEDs would be getting the approx. 5V you quote
regardless.

Well its one of those language things. Whiter LEDS need higher voltages.

But LEDs don't change colour with voltage apart from going brown and
smokey..theres always some way of limiting the current and voltage to them.

As most of the white LEDs are actually blue LEDS with a phosphor, the
colour depends on the phosphor, not on the supply current or voltage.
The colour of the blue LED stays constant over the whole of its
operating current range. The variation in colour between batches is due
to variations in the phosphor mix.

Some use 3 coloured LEDS per light element, but if you look closely, you
can see the three colours. These are more expensive, and are sometimes
used for mood lighting, where the user wishes to vary the colour on
demand. I use 'em for disco lighting, where you can definitely see the
individual (High powered) LEDs.

--
Tciao for Now!

John.

On Oct 22, 7:02*pm, (D.M.
Procida) wrote:
The shops seem to be full of LED lamps, all of a sudden.

They don't seem to be very bright though. There still doesn't seem to be
anything that's a drop-in substitute for an old 100W or 120W
incandescent bulb.

How long before they catch up?

Daniele

You can get fluorescent tube replacements up to six feet.
They cost about £10 per foot. You disconnect all the old tube starting
gear.
http://oxfordled.co.uk/

In article , wrote:
On Tuesday, 23 October 2012 20:28:19 UTC+1, John Rumm wrote:
On 23/10/2012 12:56, Alan Braggins wrote:
In article , wrote:

On Tuesday, 23 October 2012 06:58:59 UTC+1, Chris J Dixon wrote:
swimmydeepo wrote:


I've just installed 4 led down-lighters in a small bathroom...very happy so far.


My first advice? Go for low voltage ones - watt per watt 12v led gives more light (more efficient) and a more pleasant white than the high voltage bulbs

Would you care to explain that a bit more? Aren't the actual LEDs
identical, it is just the production of a suitable voltage for
them that differs between LV and mains lamps. Do you mean that
this conversion loss lowers efficiency?


I think swimmydeepo's statement comes about from the lower voltage LEDs ability to share the LED driver. Having one driver for lots of low voltage LEDs is probably more efficient than having one driver per LED.


Especially one driver per LED that has to be squeezed into the "bulb".

I don't see how it affects the colour though. Both 12v and 240v are available
in a range of colour temperatures, but the same LED ought to give the same
white at the same power, regardless of the driver efficiency.

Yup, I think that is confusing issues that apply to halogen (where LV
are "whiter"), but not LED

"but not LED"?!
Have you first hand experience or are you just assuming things? Try out by yourself and tell me....
Then, maybe, the secret is really in the driver or the fact that these 12v led bulbs runs on low voltage just like the halogen 12v - both are more efficient and more pleasant than the high voltage counterparts just because these are low voltage (what about that?).

That's obviously rubbish. "just because these are low voltage" is meaningless
when applied to the actual LED bit, which will have a fixed forward voltage
at a given current regardless of the input to the driver.

It's entirely plausible that the particular 12V LED bulbs you tried were a
better colour than the particular 240V ones you tried, but that doesn't mean
they all are.

On Tue, 23 Oct 2012 02:34:53 -0700 (PDT), Andy Dingley
wrote:

On Monday, 22 October 2012 19:02:47 UTC+1, D.M. Procida wrote:
The shops seem to be full of LED lamps, all of a sudden.

Yes, they're expensive and they're months behind what's possible.

If you want the leading edge, easily, buy direct from China via eBay.
You won't see anything BC bayonet cap, but ES, SES & GU10 are now cheap
and good. GU10s in particular are a very good replacement.

Not IMHO. All the LED GU10's I bought failed prematurely (6 months -
2 years) making them more expensive than halogens.

--
(\__/) M.
(='.'=) If a man stands in a forest and no woman is around
(")_(") is he still wrong?

On 24/10/2012 09:36, harry wrote:
On Oct 22, 7:02 pm, (D.M.
Procida) wrote:
The shops seem to be full of LED lamps, all of a sudden.

They don't seem to be very bright though. There still doesn't seem to be
anything that's a drop-in substitute for an old 100W or 120W
incandescent bulb.

How long before they catch up?

Daniele

You can get fluorescent tube replacements up to six feet.
They cost about £10 per foot. You disconnect all the old tube starting
gear.
http://oxfordled.co.uk/


Bullet point two suggests someone did not proof read their web site!

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Wednesday, 24 October 2012 09:46:36 UTC+1, Alan Braggins wrote:
In article , swimmydeepo wrote:

On Tuesday, 23 October 2012 20:28:19 UTC+1, John Rumm wrote:

On 23/10/2012 12:56, Alan Braggins wrote:

In article , wrote:



On Tuesday, 23 October 2012 06:58:59 UTC+1, Chris J Dixon wrote:

swimmydeepo wrote:





I've just installed 4 led down-lighters in a small bathroom...very happy so far.





My first advice? Go for low voltage ones - watt per watt 12v led gives more light (more efficient) and a more pleasant white than the high voltage bulbs



Would you care to explain that a bit more? Aren't the actual LEDs

identical, it is just the production of a suitable voltage for

them that differs between LV and mains lamps. Do you mean that

this conversion loss lowers efficiency?





I think swimmydeepo's statement comes about from the lower voltage LEDs ability to share the LED driver. Having one driver for lots of low voltage LEDs is probably more efficient than having one driver per LED.





Especially one driver per LED that has to be squeezed into the "bulb".



I don't see how it affects the colour though. Both 12v and 240v are available

in a range of colour temperatures, but the same LED ought to give the same

white at the same power, regardless of the driver efficiency.



Yup, I think that is confusing issues that apply to halogen (where LV

are "whiter"), but not LED



"but not LED"?!

Have you first hand experience or are you just assuming things? Try out by yourself and tell me....

Then, maybe, the secret is really in the driver or the fact that these 12v led bulbs runs on low voltage just like the halogen 12v - both are more efficient and more pleasant than the high voltage counterparts just because these are low voltage (what about that?).



That's obviously rubbish. "just because these are low voltage" is meaningless

when applied to the actual LED bit, which will have a fixed forward voltage

at a given current regardless of the input to the driver.



It's entirely plausible that the particular 12V LED bulbs you tried were a

better colour than the particular 240V ones you tried, but that doesn't mean

they all are.

Not just colour...these emit more light too (very important).
All the 240v I've tried so far can't compare in both colour and amount of light emitted (watt per watt): I've bought led lamps since last year, experimenting with different models and types: bayonet and screw type cylindrical shape with lots of leds, Powaled cluster leds (about 30?) with plastic casing, led strips too...then more recently I bought several led bulbs for downlighters GU10 3w, GU10 RGB(colour changing) and MR16 3w and also MR16 4w.

Now, I understand that many who bought the GU10 come with comments like "rubbish" or use technical data or similar...since recently, I myself have bought high voltage led bulbs for practical reasons.
Bottom end of my personal experience leave me no doubts: the 3w cool white MR16 are the best I've tried so far - better colour and more efficient than the rest...second best are (hear hear) the MR16 4w warm white - so the only 2 batches of MR16 I've ever tried so far beat all of the 240v in my arsenal.
The only 240v I've tested which is comparable to the 3w cool white MR16 are these 4w Powaled I'm using for my table lamp - it uses a plastic casing to give a warm white light which is pleasant enough - still, the 3w MR16 gives more light = more efficient that the 4w Powaled.

another important distinction I've found:
Cool white on 240v bulbs is more bluish than in the Cool white found on MR16...while the Warm white tested on 240v is comparable the the Cool White of 12v led bulbs...
Finally, the Warm white of MR16 is definitely warmer than the Warm White found on the 240v bulbs.
Now, it seems that with 240v bulbs the tone is just a bit colder and in general there might be a problem of inconsistency in the way led bulbs are being marketed.

Again....this my own personal waffle - so take it for what it is - just subjective experience from a common user who's not that interested in techy-mumbo-jumbo.

wrote:

another important distinction I've found:
Cool white on 240v bulbs is more bluish than in the Cool white found on MR16...while the Warm white tested on 240v is comparable the the Cool White of 12v led bulbs...
Finally, the Warm white of MR16 is definitely warmer than the Warm White found on the 240v bulbs.
Now, it seems that with 240v bulbs the tone is just a bit colder and in general there might be a problem of inconsistency in the way led bulbs are being marketed.

Again....this my own personal waffle - so take it for what it is - just subjective experience from a common user who's not that interested in techy-mumbo-jumbo.

Perhaps the sample size, from which these conclusions were drawn,
would be significant information.

Chris
--
Chris J Dixon Nottingham UK


Have dancing shoes, will ceilidh.

On 25/10/2012 12:48, wrote:
another important distinction I've found:
Cool white on 240v bulbs is more bluish than in the Cool white found on MR16...while the Warm white tested on 240v is comparable the the Cool White of 12v led bulbs...
Finally, the Warm white of MR16 is definitely warmer than the Warm White found on the 240v bulbs.
Now, it seems that with 240v bulbs the tone is just a bit colder and in general there might be a problem of inconsistency in the way led bulbs are being marketed.

Again....this my own personal waffle - so take it for what it is - just subjective experience from a common user who's not that interested in techy-mumbo-jumbo.


one mans or companies cool white may not necessarily be another,
especially with anything coming from China,

How about some suppliers and part numbers?

to give a little objectivity to go with your subjective experience