Re: New bulbs.
 

I’d be obliged if you would show me where I have stated that my calculator works better from a particular SOURCE of light. My statement was about the INTENSITY of the light or as you seem to have trouble working out what I mean by intensity – it is the brightness of the light. Where it comes from is irrelevant. My 60w LE bulb gives off less light than a normal 60w bulb. It is hardly noticeable to the naked eye but a light meter or solar panel can detect the difference.

A solar panel will generate a DC electric current at a particular voltage when a light is shone on it. If the light is dull the electrical energy generated will be small. If the light is bright the electrical energy generated will be sufficient to power whatever device is connected to it, in my case a calculator. There is a limit on how much electrical energy a single solar panel will generate so shining a 10Kw light onto it won’t make it generate more.

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Therefore the energy saving lightbulbs only show the parts we need.

Really? If we are to see all the various colours around us we need the full spectrum of white light. We can see all the colours around us by the light of a normal bulb and also a LE bulb. The BRIGHTNESSof the light will determine how well we will see all colours. You can’t see colours very well in full moonlight but you can in full sunlight.

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A normal lightbulb shows the full visible spectrum from red to purple including all the different shades of all the colours, every single wavelength from 400nm to 700nm. Where as an energy saving one dosn't use every single wavelength, this means it uses less energy but it is NOT less bright. It just simply uses less energy because its not outputting the same amount of wavelengths but its not noticeable to the human eye.

Oh! Yes? Then explain this. I placed an LE bulb inside a closed box that had a tiny slit on one side to allow the light out. I placed a prism in front of the slit so that the beam of light shone onto one side of a prism. Close to the hypotenuse face of the prism I placed an upright white card. Guess what I saw? A full and complete spectrum. So if an LE bulb is not generating all the colours of the spectrum as white light as you claim, where did the colours come from? Any source of visible light will split into all the spectrum colours unless, as I have already stated, certain colours are filtered out. Then you will get a coloured light. If you remove all the red element of white light you get a cyan light. If you remove the blue element you get a yellow light. If you remove the green element you will get a violet light.

Open up a paint package like Paint Shop Pro and access the palette and play around with the RGB values. RGB at 000,000,000 produces black. RGB at 255,255,255 produces white. By varying the individual values of the RGB you can get 16,777,216 different colours.

The reason why an LE bulb uses less electrical energy than a normal bulb is because more of that energy is converted to visible light than to heat. Thus for a given amount of light you need less power for an LE bulb than you do for a normal bulb.

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Oh and, the colour of light does matter because different wavelengths = different colours = different amounts of energy..... but in this case it dosn't because we're talking about all visible light and not blues/greens etc individually.

Eh?

Re: New bulbs.
 

Who do you know that we don't know? :p

Re: New bulbs.
 

"A phosphor emits light in a narrow frequency range, unlike an incandescent filament, which emits the full spectrum"

Taken from wikipedia.

Try using a magnifying glass to observe, you might notice the gaps in the spectrum then. I know they're there because i've tested this myself in the past, properly in lab conditions, the gaps were pretty clear under a microscope.

Re: New bulbs.
 

You can quote OHMS Law, you can argue till your all blue in the face, this type of bulb or lighting is cheaper to run providing you use them in the correct manner IE switch them on and leave them on, all flourecent lighting is expensive to 'start up', if you are going to continualy switch them on and off, they are neither cheap or convenient but a darned pest as the 'warm up time is too long.

Re: New bulbs.
 

There are superb articles on incandescent and LE bulbs on wikipedia and howstuffworks.com (They can be a bit scientific/techie for some people I must admit)

http://en.wikipedia.org/wiki/Fluorescent_lamp

http://www.howstuffworks.com/light3.htm

http://science.howstuffworks.com/solar-cell.htm (thought I'd add this one for Jambuttys solar calculator problem)

Effectively what they are saying is that the number of lumens is teh same, its just the colour temp of teh light that changes. its this colour temp change that makes teh calc work 'better' with incandescent light.


Jambutty,
I do have one addition, you started talking about the RGB colour palatte, I think you should investigate the difference between the RGB(sRGB) and Adobe colour spaces for when you are talking about digitised colour as there is a significant difference in teh 'amount' of colours that can be described by each

Re: New bulbs.
 

Re: New bulbs.
 

I lent my microscope to Mez, if you ask her nicely she might let you use it, it has a usb cable so you can view it on your P.C. screen.:)

Re: New bulbs.
 

I have never stated that the new LE bulbs are not cheaper to run. Indeed I have acknowledged that they are.

My point is that they are not as cost effective as the normal light bulb when you take into account the cost to buy and the life of each type, as I have already explained.

My other point is that a LE bulb rated at 60w but in fact uses 11w of energy is not quite as bright as a normal 60w bulb that uses 60w of energy. My proof being that with my calculator being a fixed distance from a light source needs to be closer to an LE bulb than it does to a normal bulb to work. All this spectrum stuff was introduced by Cyfr in some attempt to discredit my observations about my calculator.

Re: New bulbs.
 

I must agree with you there jambutty they do not appear to be as bright as an ordinary bulb, but in some situations staircases and lobbies they are ideal to leave on all the time, my point was it's how and where you use them.

Re: New bulbs.
 

Re: New bulbs.
 

Re: New bulbs.
 

I do find it amusing that the goverment tell us to turn all our lights off yet leave the street lights burning brightly all night long. couldn't they be on alternating circuits so 50% could be turned off after midnight? OK, you may want to leave major roads on but there are a heck of a lot of side roads that don't need lighting all night long.

Re: New bulbs.
 

heh, just another pointer to the sheer uselessness of joe public trying to save the environment

http://www.theregister.co.uk/2007/03/12/lights_budget/

Re: New bulbs.
 

Many people have put forward the night-time street lighting idea forward entwisi. There was burglar Bill and burglar Wally and ……. well you get the drift.

I’m not saying that having the streets lit at 3 o’clock in the morning will discourage a burglar because it probably won’t. He usually goes round the back anyway. But no lights might just encourage more. No street lights would also encourage vandals plying their trade on parked cars.

The point about these LE bulbs that some people don’t seem to have considered is the amount of energy consumed in making them compared to making a normal bulb. It has to be more. If were to hazard a guess I would suggest that the net result will be that the normal light bulb is more energy/cost efficient than the new LE bulbs.

I don’t know if anyone saw the news a few days ago where it was reported that a couple in the Lake District set up their own hydro electric scheme. It took them many years to get the planning permission required but now they have a small hydro electric unit that generates 300Kw which they sell the surplus to the National Grid. They reckon that it will have paid for itself in 10 years time and will last for more than 50 years with just minimal maintenance.

I accept that not everyone can do that but a massive hydro electric plant would be even more efficient.

Re: New bulbs.
 

Right i'll attempt again to explain it though my patience is thinning.

You can *not* use a calculator to determine how good or 'bright' a light source is.

You can't do this because calculators work from light energy. They don't express how well you see things, they can only express how much energy is there in terms of light.

Light comes in all different colours, some we can see some we can't. The different types of light are all different wavelengths all with different energy levels.

I've explained how Low Energy lightbulbs work, and as a result of the way they work they emit a white light but with more focus on the lower end of the spectrum with shorter wavelengths (The Blues) where as filament bulbs focus more on the red side of the spectrum with longer wavelengths.

Solar cells do not simply work off any light. They only work off light with certain frequencies which happens to be the red end of the spectrum, hence they don't work as well with low energy bulbs because they give off more of the blue end of the spectrum which solar panels can't use.
However this does not mean the low energy bulbs are less bright they simply emit a different side of the spectrum more strongly, if you could measure ALL the energy given off in terms of light im sure there would be enough to power your calculator properly, just not in its current form due to the inefficiency of solar cells.



Don't make such enormous assumptions such as "The energy consumed in making them compared to a normal bulb has to be more" because at the very least its a very misguided statement. I don't know for fact how much energy is used to make either bulbs, but I know you also don't know. If you happen to be right, then i'm sure the benefits of lower energy consumption easily balance any additional manufacture energy. If you can prove otherwise then I would love to hear it, but so far it seems to be a complete bombshell of a statement without any tangible evidence.

At the end of the day you're welcome to continue using traditional lightbulbs without a bad conscience. However I would hope that the rest of the country are not as stubborn and help to reduce energy consumption for the better of everyone.