SMD LED's

[Ianey]

Hi there,

Has anyone fitted the SMD LED's (Surface Mounted LED's) which are for sale on Fleabay? I'm trying to understand how bright they are and what's the difference between warm White LED Marine Bulb Lamp and Pure White LED Marine Bulb Lamp? They seem to be measured in Lumens.... But how bright is that with regards a 10 watt halogen (as an example)??

 

Has anyone any experience on this as I'm confused.. Which is normal?

 

Thanks

 

Ianey

[NB Willawaw]

They quote colour temperatures for LEDs.

 

Cool white is more blue - warm white is not as warm looking as halogens but as close as you can get with the current technology.

 

I always think that the comparative, equivalent power ratings for LEDs are a bit optimistic.

 

The best thing is probably to buy a sample light and test it for brightness and colour.

[gbmud]

Apparently one's eyes are not designed to see blue light as well as other colours, particularly yellow. So a lamp with a very white light might appear, on paper, to be brighter than a much yellower light, which the eye perceives as brighter due to being set up to see the yellow light more vividly. Apparently this is true of blue boy-racer car headlamps where the light output is much greater when measured by a light meter but in reality, actual visibility is no better - or even worse!

 

There are some LED lamps which give a really nice light akin to halogen bulbs, a friend has some in his camper as direct replacements for halogen capsule bulbs but sadly they were a chance purchase off ebay and he does not remember where from. LED technology will get there, indeed, if one spends enough money it already is. ...almost.

 

Chris

[Chalky]

I've played with LEDs and you very much get what you pay for. White LEDs are made by using an ultraviolet LED and using that to excite a phosphor to produce the white light. The common phosphors give a warm or cool light. Warm white tends to the yellow end of the spectrum, cool white has more blue in it so looks colder. Cool white LEDS usually have higher light outputs. In total darkness your eye is more sensitive to the blue/white light and they will "appear" to be significantly brighter - up to 2.5 times brighter than pure white light (Photopic & scotopic vision)

 

Because of the way LEDs work the relationship between power in and light out is not the same as a bulb. When they make a batch of LEDs some produce more light than others. The LEDs are selected into batches and the pest light producing ones are sold at a premium price. They then select the next ones and so on. Cheap lights will tend to use the lowest grade of LEDs, more expensive ones the best. Consequently power in watts is irrelevant - you need to look at lumens which is the measure of the light produced. I've just built some lights for my cabin with LEDs that produce 400 lumens. They are significantly brighter that 20W halogen.

 

LEDs need some electronics to make them work - can vary from a simple resistor up to a full electronic power supply. You get what you pay for. Some can waste power as heat, others can cause radio reception problems. Well designed ones don't. Unfortunately you won't know which is which until you try them - especially if you buy them of ebay.

 

LEDs theoretically should outlast all of us however that can be killed quickly by excessive heat. Cheap LED lights tend to have very poor heat management and this will kill them quite quickly. Often they'll start to change colour then fail. A good LED lamp will have a metal heatsink built into it.

 

As Alan said, buy one and try it.

 

LED technology is changing rapidly. 2 years ago a high spec power LED chip (to be built into a light) would produce 240 lumens at 4W and cost about £8. I've just used LEDs that cost £3 and produce 500 lumens at 4W.

[johnmck]

Hi.

 

We sourced our lighting from this company.

 

http://www.ideallights.co.uk/corporate/index.php

 

Brilliant, but not cheap!

 

John.

[Chalky]

Apparently one's eyes are not designed to see blue light as well as other colours, particularly yellow. So a lamp with a very white light might appear, on paper, to be brighter than a much yellower light, which the eye perceives as brighter due to being set up to see the yellow light more vividly. Apparently this is true of blue boy-racer car headlamps where the light output is much greater when measured by a light meter but in reality, actual visibility is no better - or even worse!

 

 

In daylight your eye is more sensitive to red / green and fairly insensitive to blue. At night it's insensitive to red, but really sensitive to blue/green - the colour of moonlight (once you've fully dark adapted). The eye when dark adapted is 2.5 times more sensitive to "cold white" light. If you're going to measure it use a photometer that is corrected for the eyes colour response, not just a pure optical power meter.

[ditchcrawler]

Most of the lights on our boat are LEDs. I have bought some cheap on fleebay but they have not lasted long.

[Bob18]

Recent research has shown that the human eye responds to blue light a lot more than was thought, indeed there are reports of people who have no conventional photo receptors being able to "see" in blue light, but not in the red/yellow areas of the spectrum. This has lead to the discovery that we actually have another type of receptor for blue light that gives a lot of chroma information to the other receptors. This is probably why those intense blue LEDs are so annoyingly bright.

[Chalky]

Most of the lights on our boat are LEDs. I have bought some cheap on fleebay but they have not lasted long.

 

I got some from fleebay. The heat sinking was non existent and they failed due to overheaing. My latest ones are converted bulkhead lights. The parts cost £15 for the conversion, but they're bomb proof and very bright. I'm looking at winding the brightness down. Wasily out perform a 20W halogen and use 300ma.

[Bob18]

I've had the cheapies from ebay, and they and they have lasted a short time, and too much hassel to get my money back. Replaced with more expensive LEDs from a couple of the common advertisers, one failure out of over 100, replaced foc on a phone call with the instruction from them "Don't waster your money sending it back, we'll send you a new one", which they did.

 

 

 

There are two things to think about, colour temperature and colour rendition.

Colour temperature is quoted for most white LEDs, with ~2700K as "warm white"; ~4400K as "daylight"; and 6000K as cool. Most halogen lamps are in the region of 2200-3000K, and tungsten filament lamps 1600-2200K.

Colour rendition is an indication as to how well a range colours are rendered in a given light, there is not a simple relationship between colour temperature and colour rendition, and the scales used vary; there are two main scales 0-1 and 0-100, the nearer the end of the scale you are the better, most halogen lamps score well over 80 while sodium street lights score about 5 (on the 0-100 scale); EFLs score about 60, and old tungsten filaments about 70 on the same scale.

[Guest]

Some very good advice above. Shame the suppliers are not as well informed.

I have swapped all my lighting and found that you can find decent stuff on ebay, but it is a bit of a lottery!!

 

Be aware as well that the SMD leds all give a wide angle (diffused?) light. If you are replacing an MR11/16 spot then the beam angle will be totaly different if you get SMD LEDs. The closest replacement, if you want a concentrated beam are the devices which have the dome shaped LEDs. Like This;-

 

Edited October 16, 2011 by Floating Male

[Bob18]

How bright is an xWatt LED?

It depends on several things so there is no simple answer.

The best you can do is look at the Lumens output of the LED, then divide that figure by 10 and that ROUGHLY gives you the equivalent power halogen lamp, but only ROUGHLY.

 

So an LED giving 300 Lumens is roughly as bright as a 30W halogen lamp. But exactly how it compares will depend on the angle, the colour, how its mounted, the shape of any lenses, reflectors, filters and so on.....

 

While it is true most SMD LEDs are wide angle, there are a few narrow angle devices out there. The cut-off on an LED is very sharp compared to that of either a halogen of filament lamp.

 

Its a hard question to answer correctly without the curves and charts for both the halogen you are replacing and the LED you are thinking about. However, talk to the more established UK based suppliers, those who have been around focussing on LEDs for a time (not the general suppliers) and take guidance from them, and be prepared to get a sample to see it works for you, in your situation.

[Ianey]

Hi all,

I thought I'd give an update to my original question (and thanks for the replies in the thread) as I've now got my boat and I've just taken delivery of SMD LED's from a far far away land.... and this is what I found...

 

All the following lights are rated at 0.9watt....

 

These have a Light Color: Pure White (6500~7000K)

http://www.ebay.co.uk/itm/220865035087?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

 

In reality... VERY VERY white and most definitely the brightest, BUT they take some getting used too....

 

These have a Light Color: White (6500~7500K)

http://www.ebay.co.uk/itm/270794740832?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

 

In reality.... Again, VERY VERY white but not as bright as the one above.....

 

These have a Light Color: Warm White (3000~3300K)

http://www.ebay.co.uk/itm/330543859737?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

 

In reality.... The light is more a 'normal' yellow feel rather than the pure white from the first two and also, I found they're slightly brighter than the 10watt halogen's I'm replacing them with so it's a big from me as they use less than a tenth of the power.....

 

Hope this helps someone else with the same question I had?

 

Ianey

[Nemysys]

I've just replaced the 10w festoon bulbs in a couple of our ceiling cabin lights with a 36 SMD LED matrix which came with a festoon adapter. Just plug in and go at less than 2 quid each from fleabay.

 

The LEDs are much brighter than the bulb. Can't vouch for how long they will lat though.

[PaulG]

Hi all,

I thought I'd give an update to my original question (and thanks for the replies in the thread) as I've now got my boat and I've just taken delivery of SMD LED's from a far far away land.... and this is what I found...

 

All the following lights are rated at 0.9watt....

 

These have a Light Color: Pure White (6500~7000K)

http://www.ebay.co.uk/itm/220865035087?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

 

In reality... VERY VERY white and most definitely the brightest, BUT they take some getting used too....

 

These have a Light Color: White (6500~7500K)

http://www.ebay.co.uk/itm/270794740832?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

 

In reality.... Again, VERY VERY white but not as bright as the one above.....

 

These have a Light Color: Warm White (3000~3300K)

http://www.ebay.co.uk/itm/330543859737?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

 

In reality.... The light is more a 'normal' yellow feel rather than the pure white from the first two and also, I found they're slightly brighter than the 10watt halogen's I'm replacing them with so it's a big from me as they use less than a tenth of the power.....

 

Hope this helps someone else with the same question I had?

 

Ianey

Hi,

I'm experimenting with LEDs myself and the problem with all of the products you have listed there is that the input voltage is shown as 12V DC.

The supply voltage on the boat will normally be higher than this.

 

Depending in your charging arrangement and battery type, the absorption/acceptance voltage when charging will usually be between 14.0 and 15.0V, and some chargers have an equalisation stage that can be anywhere between 15.0 to 16.5V for several hours.

 

Over voltage kills LED's pretty quickly.

 

Personally I wouldn't use any of those on a raw DC boat supply as it doesn't state that they are designed for the supply voltage.

 

Of course if you have a stabilised 12V supply they're probably fine.

 

I have tried these:

Fleabay link

 

These have a stated working voltage of 10 to 30V DC, so would take account of most of the day to day requirements of a boat supply, but not of course voltage spikes which can be higher than this.

 

Please note that these are out of stock at the moment, I am just using them as an example, and I am not particularly pushing this product or seller - other similar lamps are available!

[PaulG]

Further to the above, if you want to run 12v LEDs when their working voltage range is not stated or unknown, you might think about using one of these as a cheapie 12V led driver:-

 

Car charger

 

This is an adapter for various models of Asus laptop that conveniently use a 12v DC supply.

 

The working supply range is stated as 10.5 to 28 volts, output 12V at up to 3A.

 

I have just tested one of these, and under zero load conditions the output was stable at 12.45V +/- 0.02V over a supply range from 4.5V to 28V.

 

When I get more time I will try and test again under load and try to get some measure of efficiency.

Edited February 24, 2012 by PaulG

[Springer Skipper]

Thank you for your research,old numptys like me appreciate it,I am still in the acetylene lamp age!

It didnt occour to me to get a voltage regulater like that.I was looking at much more expensive bits of kit,you deserve a greenie.

Robin

[ditchcrawler]

All the ones I have come from Ultraleds My supply is a nominal 24 volts and have not experienced any problems yet. I don't have a shore supply and charger but I do have an Adverc external alternator controller.

[Pretty Funked Up]

Depending on your setup and if you dont mind soldering check out LM2940CT 12 Volt 1 Amp Low Dropout Regulators. Thet'll run 400mA without a heat sink or upto 1A with a heatsink.

 

My main lights are 4 bars of LEDs each using 150mA. Wired them as 2 sets of 2 and the regulators cost £2 (£1 ea.).

[PaulG]

Depending on your setup and if you dont mind soldering check out LM2940CT 12 Volt 1 Amp Low Dropout Regulators. Thet'll run 400mA without a heat sink or upto 1A with a heatsink.

 

My main lights are 4 bars of LEDs each using 150mA. Wired them as 2 sets of 2 and the regulators cost £2 (£1 ea.).

That would certainly help to protect the LED's, but is not terribly efficient as all that it effectively does is to dump power in an overvoltage condition, which is why you need the heatsink.

It is undeniably very cheap, though!

The drop-out voltage of 0.5 volts together with a bit of voltage drop due to cabling could be enough to appreciably reduce the light output of the LED's. Depends on what you want out of your installation, really.

[Pretty Funked Up]

That would certainly help to protect the LED's, but is not terribly efficient as all that it effectively does is to dump power in an overvoltage condition, which is why you need the heatsink.

It is undeniably very cheap, though!

The drop-out voltage of 0.5 volts together with a bit of voltage drop due to cabling could be enough to appreciably reduce the light output of the LED's. Depends on what you want out of your installation, really.

 

Hiya

Yeah I wanted cheap, affective and easy to hide.

Theyre nearing 4 years hard work now with no problems at all. I guess there maybe a slightly more efficient way but how much more, would it total a whole 1% more efficient?

[Nickhlx]

There are constant current drivers on e-bay made for e.g 5 W COB lights - these work from, for example, "7-24 Volts DC" to give a constant current drive of 950mA or so, and are purpose designed to drive a certain power LED and have no heat sink - From the components on the ~ 15mm square PCB it seems they are switching devices and presumably quite efficient.

http://www.ebay.co.u...=item230f284711

 

I have been experimenting with a few from this site http://stores.ebay.c...fsub=1945173013

and a step up/step down regulator, such as http://www.ebay.co.u...f#ht_4874wt_954 which gives a constant voltage ouput which is not ideal as the current changes with e.g. temperature of the LED

 

What is looking "favourite" though is the use of COB LEDs, probably the 3W and 5W types, working from 9 or 10 volts, and current driven

by a variable module where you can set the current limit and voltage limit. Even 1 W is bright enough for some applications although not a COB LED.

 

It's either that, or a module to provide around 20 volts and then separate converters for each string as required and appropriate such as http://www.ebay.co.uk/itm/LM2596-DC-DC-Step-down-Adjustable-Power-Supply-Module-Converter-/230752080136?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item35b9e55108#ht_3274wt_1187

as LEDs really need to be driven with constant current.

 

The simple answer is the first link, but I like fiddling and exploring other options...

 

 

 

Nick

Edited February 25, 2012 by Nickhlx

[PaulG]

Hiya

Yeah I wanted cheap, affective and easy to hide.

Theyre nearing 4 years hard work now with no problems at all. I guess there maybe a slightly more efficient way but how much more, would it total a whole 1% more efficient?

Actually, I see that the efficiency of the device that you are using is better when it is being supplied from higher voltages!

This is a bit counter-intuitive, but it's a design feature.

The data sheet says that "The quiescent current with 1A of output current and an input-output differential of 5V is therefore only 30 mA. Higher quiescent currents only exist when the regulator is in the dropout mode (VIN − VOUT ≤ 3V)".

In plain English this means that the 12V version is most efficient when being supplied with 15V DC or more, i.e. when you are charging.

 

It actually gets less efficient as the difference between the supply voltage and the output voltage reduces, i.e. when you are running on battery power.

 

This of course is the opposite to what you would want in an ideal world!

On the plus side, it does have some transient protection.

It obviously works for you, so I wouldn't knock it, though

 

There are constant current drivers on e-bay made for e.g 5 W COB lights - these work from, for example, "7-24 Volts DC" to give a constant current drive of 950mA or so, and are purpose designed to drive a certain power LED and have no heat sink - From the components on the ~ 15mm square PCB it seems they are switching devices and presumably quite efficient.

http://www.ebay.co.u...=item230f284711

 

I have been experimenting with a few from this site http://stores.ebay.c...fsub=1945173013

and a step up/step down regulator, such as http://www.ebay.co.u...f#ht_4874wt_954 which gives a constant voltage ouput which is not ideal as the current changes with e.g. temperature of the LED

 

What is looking "favourite" though is the use of COB LEDs, probably the 3W and 5W types, working from 9 or 10 volts, and current driven

by a variable module where you can set the current limit and voltage limit. Even 1 W is bright enough for some applications although not a COB LED.

 

It's either that, or a module to provide around 20 volts and then separate converters for each string as required and appropriate such as http://www.ebay.co.uk/itm/LM2596-DC-DC-Step-down-Adjustable-Power-Supply-Module-Converter-/230752080136?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item35b9e55108#ht_3274wt_1187

as LEDs really need to be driven with constant current.

 

The simple answer is the first link, but I like fiddling and exploring other options...

 

 

 

Nick

Some interesting stuff, there Nick - please let us know the results of your fiddling!

Edited February 27, 2012 by PaulG

[leeco]

There are constant current drivers on e-bay made for e.g 5 W COB lights - these work from, for example, "7-24 Volts DC" to give a constant current drive of 950mA or so, and are purpose designed to drive a certain power LED and have no heat sink - From the components on the ~ 15mm square PCB it seems they are switching devices and presumably quite efficient.

http://www.ebay.co.u...=item230f284711

 

I have been experimenting with a few from this site http://stores.ebay.c...fsub=1945173013

and a step up/step down regulator, such as http://www.ebay.co.u...f#ht_4874wt_954 which gives a constant voltage ouput which is not ideal as the current changes with e.g. temperature of the LED

 

What is looking "favourite" though is the use of COB LEDs, probably the 3W and 5W types, working from 9 or 10 volts, and current driven

by a variable module where you can set the current limit and voltage limit. Even 1 W is bright enough for some applications although not a COB LED.

 

It's either that, or a module to provide around 20 volts and then separate converters for each string as required and appropriate such as http://www.ebay.co.uk/itm/LM2596-DC-DC-Step-down-Adjustable-Power-Supply-Module-Converter-/230752080136?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item35b9e55108#ht_3274wt_1187

as LEDs really need to be driven with constant current.

 

The simple answer is the first link, but I like fiddling and exploring other options...

 

 

 

Nick

 

 

Hi Nick

 

Do you think something like this would work?

 

http://www.ebay.co.uk/itm/Low-Ripple-CC-CV-Car-Power-Supply-Module-LED-Driver-DC-DC-8-30V-2-16V-80W-/290638854047?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item43ab6cf79f

 

Lee

[Radiomariner]

Little .

A few nights ago on Radio 5 Live, on one of those late night science news programmes, a chap was talking of the advancement of LED's.

It seems scientists have been checking power out with power in to these divices, by continuously reducing power and measuring output.

Amazingingly they found a point where the power out was nearly twice that of that they put in. Impossible?

No. It seems that at a certain point the LED's draw energy from the surrounding atmosphere reducing the air temperature. Early days yet, but they expect this to be of signicicance in the field of reftidgeration!