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Old Wednesday, May 13, 2015
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Default Define LED Energy

What is the definition of LED energy.Is it the same as LED(Light emitting diode).
Or do we have to talk about uses of LED in saving energy consumption?a
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Old Wednesday, May 13, 2015
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Quote:
Originally Posted by Nazish Hina Shafiq View Post
What is the definition of LED energy.Is it the same as LED(Light emitting diode).
Or do we have to talk about uses of LED in saving energy consumption?a
"LED Energy" is neither any term found in Electrical engineering nor its a type of energy . its actually about LED, light emitting diodes (as you have mentioned) which are energy efficient.
i think in this topic you have to talk about the technology of LEDs with main focus on the efficiency of LEDs in term of energy saving (Comparison with incandescent bulbs or tubes) . You can find a sufficient stuff about LEDs on internet.
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I know, BUT the syllabus given by FPSC says
Sources of Energy (Renewable i.e. LED Energy, Solar
Energy, Wind Energy)and Non-Renewable Energy conservation and its sustainable use.
I hate their idiotic syllabus.
I made all other notes easily but this was WIERD.
Thanks for your help!!
Really liked the smiley though
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Old Wednesday, May 13, 2015
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LEDs are two way semi conductor light source. It can also be called pn junction diode.
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Quote:
Originally Posted by Nazish Hina Shafiq View Post
I know, BUT the syllabus given by FPSC says
Sources of Energy (Renewable i.e. LED Energy, Solar
Energy, Wind Energy)and Non-Renewable Energy conservation and its sustainable use.
I hate their idiotic syllabus.
I made all other notes easily but this was WIERD.
Thanks for your help!!
Really liked the smiley though
LED energy never heard of that during my electrical engineering.
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Old Thursday, May 14, 2015
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Post Led energy

It is quite hilarious to have LED(Light emitting Diode) *ENERGY* under the umbrella of "Renewable Energy Sources."

How blindly and bluntly the syllabus has been organised. Anyway, perhaps energy consumption - in industries in general and houses and shops in particular - and its(energy's) efficient usage are what made the syllabus-maker add it in the energy portion.

However, it has nothing to do with renewable energy source.

P.S: The thing making me curious is the notion "i.e." after renewable. Confidence of the syllabus-maker is unmistakable.
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Default Led

Can anybody post complete information on the topic LED?

Waiting
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Old Thursday, May 14, 2015
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Quote:
Originally Posted by IslamabadKid View Post
It is quite hilarious to have LED(Light emitting Diode) *ENERGY* under the umbrella of "Renewable Energy Sources."

How blindly and bluntly the syllabus has been organised. Anyway, perhaps energy consumption - in industries in general and houses and shops in particular - and its(energy's) efficient usage are what made the syllabus-maker add it in the energy portion.

However, it has nothing to do with renewable energy source.

P.S: The thing making me curious is the notion "i.e." after renewable. Confidence of the syllabus-maker is unmistakable.
This confidence is too much for me.its my first week int prep
and
The syllabus maker has made it so hard already.
I'm going to write about energy conservation and role of LED's in it.
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Old Thursday, May 14, 2015
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Default An Introduction To LEDs

Our need for light
It's impossible to imagine modern life without electric light. So much of our working lives, our leisure time, and the running of our 24-hour-a-day cities, depends on a clean, safe supply of illumination.
But all this light is expensive to generate and uses a lot of energy. The traditional incandescent light bulb is a highly inefficient piece of technology, little changed from the original bulbs developed in the late nineteenth century.
Fortunately, scientists and engineers have come up with something that might be the solution.

21st Century Light

We take for granted how easy it is to switch on a light and pierce the gloom. The UN calls this a basic human right. But the technology most of us use dates back to the 1800s.Worldwide, a fifth of all the electricity we generate is used for lighting. Now this gives us a hefty energy bill – but it also means we pump out three times more carbon dioxide than the entire aviation industry.
And the need for light is only going to get bigger, as our populations grow, modernise and move into cities.
Living in darkness isn’t an option. But there’s a development that could slash our energy consumption.
The traditional light bulb is actually a pretty hopeless way of making light. It takes loads of electricity to generate just a little bit of brightness.
LEDs or light emitting diodes have been around since the sixties but people are getting really excited about them now.
Breakthroughs in their design means that LEDs are real contenders to replace the wasteful filament bulbs in most places. And as LEDs use a fraction of the energy to create light, this simple electronic component could have a global effect

How LEDs use quantum physics to shine
Incandescent light bulbs only convert 10% of their energy into light, with the rest lost as heat. LEDs generate light in a completely different way - but how? And why are they so much more efficient?
For over a hundred years, we’ve lit up our homes with incandescent light bulbs that work in a pretty simple way.
An electrical current goes through a thin wire tightly coiled inside the glass bulb. The current makes the wire get very hot and glow. And that gives off the light, but it’s pretty inefficient. 90% of the energy is lost as heat.
LEDs make light in a completely different way – and they use the curious world of quantum mechanics to do it.
Inside an LED are two layers of special material made from semiconductors. One layer contains a lot of energetic electrons. The other layer is filled with holes – which are really broken chemical bonds between atoms.
When an LED is hooked up to a battery, the electrons and holes flood towards the place where the two layers of the semiconductor meet. As soon as an electron meets a hole in this region, it falls into it, and repairs that chemical bond. In a flash, it releases the energy that it was using to move about – as a bright light.
And that keeps happening, as the battery keeps pushing electrons and holes towards each other.
Because most of the energy goes into making light rather than heat, LEDs are super-efficient.
And as new types of semiconductors are being developed, scientists are rapidly improving the efficiency of LEDs. In a few years, LEDs on the high street could be 10 times more than today


source:BBC I wonder
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Old Thursday, May 14, 2015
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Post Led

Being an Engineer, I must say (that) the topic itself is quite broad in nature.

If you want to have complete "information" about LED, you first need to understand the semi-conductors, doping, sort of depletion region etc.

Underlying gist is that, which I assume and firmly believe, this topic must be touched from the surface. What I really mean to say is that you need to be aware of its basic functionality - which is hardly going to be asked, its significance - which is incredibly important and vital, and how it can make a prominent, economical difference by preferring LED lighting to incandescent bulbs and compact fluorescent lamps. Some facts - real and authentic - related to LED lighting must be gathered from internet. Take the countries like US, UK etc. and take their figures for comparison, or maybe for devising the plan for the betterment of Pakistan's economy by comparing it "with" their plan of LED lighting.

I do not have my notes with me right now, but I do remember the link, which is energy.gov. Go there and explore a bit about LED lighting(for practical usage). Other than that, the basic functionality you can get about it from the wikipedia page, or you may explore YouTube and type in the search "Light emitting diode".

Regards.
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