Energy saving light bulbs

Quoted wattage figures rarely match reality, and in fact with LED's reality is often significantly lower, but nobody complains as the light output is so good. 14w total would indeed confirm that less than 14w is being dissipated as heat (bearing in mind that there would also be light energy being emitted, and the laws of physics determine that energy in = energy out, albeit in different forms). That is, unless the LED is allowed to draw current without limitation, where it will eventually overheat and die.

Whilst LED technology has evolved MASSIVELY in recent years, some constants remain - they are, when all is said and done, a diode, and by their very nature they pass electrical current in one direction only (lighting every half-wave, unless of course there is a full bridge rectifier and smoothing capacitors in front, which there often is); Mains electricity comes into the home as AC (Alternating Current) which I feel I can best describe as waves striking a beach - it comes in (live) and rolls out (neutral), and makes the change between the two 50 times a second (50 Hertz or 50 Cycles as it was noted in years past). As LED's are primarily directional, they are more like your garden hose in as much as the electricity will only flow out one way and not back the other (very general, see Schottky diode for the less general view); so, if a poor power supply is involved, you will potentially have a flickery light (not necessarily to the naked eye, but a camera will pick it up) and worse still circuitry that is referenced to mains voltage (not nice if you touch it!)

The heatsinks on LED's are not there to dissipate heat that you or I would necessarily feel (although if you felt a 1 watt resistor when it is passing too much current, you would still burn your finger) - they are there to keep the LED cool, and therefore ensure that it remains reliable and stop it burning up. If left to their own devices (unlimited), a diode of any form would continue to pass electrical current, and allow more and more through until it failed catastrophically.

I have recently bought a couple of Philips LED bulbs to replace standard incandescents in my bedroom and staircase, and if I did not tell you that they were LED's, I guarantee you that you would not tell them apart from incandescent bulbs.

As someone who suffers with eye/vision issues, CFL's and I never got on, and with EU banning incandescent lights, I was destined to return to candles (and @shiney thought he was a Luddite!) - LED's have completely removed this risk for me, whilst also saving me vast amounts of electricity overall.

And as with anything else, the old adage holds true - buy cheap, buy twice. If you haven't already ventured down the LED path, do yourself a favour and buy a Philips LED bulb (about £6 roughly) and whack it into an ordinary ceiling rose in a chosen room, and give it a whirl - I would be surprised if you were disappointed.

The main difference between el-cheapo LED lamps and the quality fellows, is actually not the LED chip itself (it does have some part to play, of course) - rather, it is a superior power supply circuit that limits the current being supplied to the LED (prevents over driving), and also smooths out the bumps in the supply, that are inevitable when we correct the supply from the AC (dual polarity) that comes from our mains supply, to the DC (single polarity) that is required by the LED chip itself; this attention to detail means that we get a useable light that does not emit a lot of detectable heat (they are still dissipating heat, even though we cannot feel it), whilst also ensuring

 

We've had them quite a while in a lot of areas around here, and now it seems really odd when we go from LED lit streets to those with sodium lights - and the sodium comes off much worse in terms of visibility levels. Give it time, and you will see what I mean.

 

I agree. I mentioned in an earlier post that the downlighters also cause more reflections in my glasses. Which is something that doesn't happen with more diffused light.

Although I suppose they have now brought out a more diffuse version of LED.

 

It is flat and rectangular This is what we were taught in school

 

I remember when they were still swapping over from these.



When I was at school they still had these gaslamps along the road (we really did ). We used to chat to the lamplighter when we came out of school and he used to tell us stories about his work.

A bit of info:- the crossbar just below the lamp is for propping a ladder against. In the early days the gas tap needed to be turned on by hand. They modernised it by changing the tap to a lever which had a small chain attached. At the end of the chain was a loop and the lamplighter had a hook at the end of the pole where he just pulled the lever. Then he used the lighter to light the lamp. When he came to turn it off he just pushed the lever back up. There were different end attachments for the different jobs. He had a company vehicle for the job - a bicycle!

 

I buy incandescent bulbs in my local trade warehouse at about 20p each.

 

We replaced the gas light in the kitchen when we had it redesigned about ten years ago. I still miss it when we have power cuts