It’s the final switch off for incandescent light bulbs

I changed all my bulbs back from CFLs to incandescents; My vision was failing, the rest of the family were complaining about the same thing, it just became difficult to see properly. We tried different CFLs nothing changed, 2 reception rooms have multi bulb chandlers and up-lighters, even with all bulbs lit it felt as if we were in perpetual twilight, It was worse than the old gas lamps and candles [for those who remember]. As soon as we changed back we could see properly again. Just 1 60W clear incandescent lamp enabled us to see properly when 10 CFLs failed to.
I have no idea if it is something to do with the wavelengths that make up of the white light being loaded at different ends of the spectrum, but I fear if I continue to use this type of bulb I will go blind.
Having read this, maybe It’s time to get out the old RS catalogue and start experimenting with LEDs again.

“White” LEDs are in fact blue / ultra violet LEDs with a phophor to convert it into a visible spectrum, but still with the peaks you get with fluorescent lamps.
I doubt the fluorescent spectral distribution is the cause of the problem – they are pretty good at having a good spectral distribution with modern phosphors. I suspect it is using CFLs of too low power – as wavechange says, small physical size does only permit low light output. If you can fit larger lamps, check that their light output (given in Lumens on the package) matches or exceeds that of your incandescent (allow 12 to 14 lumens per watt for a traditional incandescent bulb, and 15 to 20 lumens per watt for the more efficient tungsten halogen lamps that you can still purchase – these may be a better solution for you than CFL)

As I mentioned previously, I have replaced some CLFs with LEDs and they seem to do everything I want. They turn on immediately, are dimmable and give a nice white light. My only criticism is that they are relatively low in light output and I need to use two in each lamp holder to get an acceptable level.

This does mean buying adaptors that allow two lamps to fit into each lampholder and this task is made difficult since these adaptors, once so common, are no longer sold in the UK (although nobody seems to know why this should be). They are readily available in the USA and Canada, which is where I bought mine – although they are, of course, ES fittings and so a bayonet to ES adapator is also required, along with ES-cap lamps.

They are pricey at present, but I should recover the cost in less than a year on electricy savings and their expected life – several times longer than CFLs – should ensure that replacement will not be needed for some years.

I didn’t mean to suggest the CFLs aren’t reliable – I have had good service from mine although I have had maybe three fail in the past 7 years (which is when I went over to all CFLs in my bungalow). But LEDs are supposed to have a service life of over 50,000 hours – probably five time as long as a CFL.

So the £12 – £14 cost of an LED does begin to make more sense, even in replacement costs. And when you consider that the power consumption is only of the order of 8 watts the cost savings really add up.

So far as light output is concerned, an 8 watt LED – presently the highest rated bulb I could find – has an output equivalant to a 60 watt tungsten incandescent – so the two in each of my fittings give a light output equivalent to rather more than a single 100 watt incandescent.

Wavechange, I think your fears are correct – high temperature reduces the phophore light conversion efficiency, so high power LED devices are probably better with a cluster of lower power LEDs than thrashing ones to high powers. A 100W bulb equivalent seems around 20-25W LED, which, because they are such small devices individually, requires very effective heat sinks and distributed LEDs to maintain efficiency.

If you have an incandescent lamp then I’d just replace it. It’s their sale that is banned. Otherwise you could fit a halogen or CFL lamp – just make sure they physically fit (CFLs can be longer than incandescent).

I bought a set of 4 LEDs from SimplyLED and used two of them in each luminaire using an adaptor that allows for the use of two lamps in one lampholder. As I have written elsewhere, I had to buy the adaptors in Canada since these once-common items are no longer sold here for some inexplicable reason. The lamps were of the dimmable type and I used my existing dimmer switch.

After around six months one of the lamps failed without warning and SimplyLED replaced it without demur, making the point that I had to use a special type of dimmer switch with LEDs. I bought one of the correct switches but before I could install it another bulb failed. Shortly after fitting the new dimmer yet another bulb failed. The luminaires are the normal open pendant type and the LEDs do not get all that hot.

SimplyLED have no idea why the bulbs should have failed and suggested it might be a voltage spike – although I am inclined to doubt that as I have had my supply monitored following problems with my solar panels and EDF’s printout showed no voltage out of tolerance over a period of some weeks.

SimplyLED have now replaced all four LEDs and I have replaced the dimmer unit with a normal switch. I have not yet reinstalled the LEDs but will take a note of the installation date and see how they last. Whereas SimplyLED replace faulty bulbs free, it is not convenient to have to wrap up the old bulbs and send them back – neither is the postage cheap.

I have not yet heard from SimplyLED as to the reason for the failure, but if it is due to a voltage spike then I can only say that LEDs are simply not suitable for purpose, since no grid supply is immune to an occasional spike.