Why do CFL's go bad? ...what makes a Florescent tube go bad?
edit:
Other than dropping them! Dammit.
I just took one of these CFL's apart after it had burned out, and if I hadn't dropped it would I have been able to use the bulb for my experiements?
Other than this, there's quite a bit of circuitry involved under these housings; after dissassembling the houseing, the whole inside of this thing bas charred black. Something literally burned up in it. Are these things really safe at all?
I mean, the thing died in such a way that the two leads from the AC source are melted completely through! They seem to have touched some part of the circuit near a diode...or something that melted to death.
Wow, these little things are a treasure trove of parts!
I seem to be the only one posting on this thread, I decided not to repost an old idea, but bump this one.
My friend described to me, something that I found disturbing: He said that his lamp fell over, it had a CFL in it at the time. He said that it broke, twist bulb and all, and that it remained lit .. as if to say, it continued to arc even though the bulb had shattered. He went on to say that he had to unplug it from the wall to get it to stop.
Is this even possible? Am I not hearing about the horrors of these types of devices?
Quote from: jadaro2600 on December 06, 2009, 11:19:21 PM
...Is this even possible? Am I not hearing about the horrors of these types of devices?
Well, I can give you another 'horror'. CFL's are a source of mercury, I've been told. Breaking one is the worst thing you can do.
Also, be careful. High voltage(usually 1,000-2,000 VAC) is required to initially light the bulb, but ballast circuits are designed to lower the maintenance voltage to avoid wasting power after the bulb is lit.
--Lee
hey,
i have never had a GE cfl to go bad so far...
but the other i have noticed.. that the transistor goes or the inductor...
but alot of the sylvania bulbs .. filament or gas get weak
hope this helps
Quote from: kooler on December 07, 2009, 01:15:30 AM
hey,
i have never had a GE cfl to go bad so far...
but the other i have noticed.. that the transistor goes or the inductor...
but alot of the sylvania bulbs .. filament or gas get weak
hope this helps
I thought of that later. Electrical filaments are built into the ends of the bulbs and when one breaks, it stops working.
Creative Science has high voltage, high frequency schematic(s) that they claim will start a fluorescent bulb with just that kind of current after it's burned out.
--Lee
I had a teacher explain this one time as to why they can go bad. It basically boiled down to bad manufaturing. He explained that one can last on a normal basis of about 5-10 years, but when the gas leaks out and oxygen cords the circuts is when they go bad. Also he said to stay the hell away from any that change colors because he had one go super hot on him onetime and almost burned his shop down with it.
every burned out one ive seen appears to be that, burned out
i am not sure if the contacts fry up or if the "filament" actually does burn up, really interesting question though...
Like all physical products somethings got to give. It is most annoying when the product is guranteed for 10 years and it fails after a week.
All of this is rather disturbing, the initial post was what got me to thinking about them - it literally fried itself on the inside.
some info on CFL's and failure modes.
http://creativelightingllc.info/fluorescent_lamp.htm
One thing that many do not appreciate is that flourescent tubes should be operated with a clean sine wave with as little DC unbalance as practical so as to eliminate migration of gaseous atoms towards one electrode. The blackening will show up rather quickly when used in a circuit with some DC present.
Using flyback pulses will thus shorten the life of the tube. That is why common CFL driver circuits switch to a resonant mode after ignition. The Moyer oscillator is used in many backlighting schemes for long tube life. It has a clean sine wave output.
Many who experiment using flyback pulses to ignite the tube never really measure the Lumen output accurately, but if they were able to drive the tubes to the same intensity as a normal driver circuit, they would notice an accelerated blackening and thus a shorter life of the tube.
CFL's are designed to go bad because of economic reasons.
If they would last forever they would not be selling them anymore would they? ::)
They have been designed to stop working at a pre defined point.
The gas does not wear down and it is possible to build a CFL that would last forever, but the ones you buy in a store do not,it's designed that way.
Marco.
Quote from: jadaro2600 on December 07, 2009, 05:03:16 PM
All of this is rather disturbing, the initial post was what got me to thinking about them - it literally fried itself on the inside.
A short circuit in any part of the circuit might do that. However, I've never seen one destroy itself the way you describe.
--Lee
Quote from: -[marco]- on December 07, 2009, 07:52:41 PM
CFL's are designed to go bad because of economic reasons. ...
Very good. Money has to be made at the cost of commercial efficiency.
--Lee
QuoteCFL's are designed to go bad because of economic reasons.
If they would last forever they would not be selling them anymore would they? ::)
They have been designed to stop working at a pre defined point.
The gas does not wear down and it is possible to build a CFL that would last forever, but the ones you buy in a store do not,it's designed that way.
Marco.
Forever is a long time.... Engineers do not speak in terms of forever, but recognizing that all things have a finite life, try to design items that are both affordable and have a reasonable life expectancy. MTBF....is used to evaluate and optimize designs so that these realistic goals are met.
I urge anyone who can outhink/outdo/outperform the engineers who have skilfully developed the current reasonably designed and affordable CFL's to do so....the world will beat a path to your door.
a wireless CFL would be great
I know Tesla had wireless bulbs, but didn't he use some sort of button, carborundum? Is it possible to light fluorescent bulbs with a receiver attached to them or just the one wire like Tesla used?
As we know, you can light fluorescent tubes with no wires, just put them in an RF field with enough ionizing energy and there will be light.....but the light will be rather dim unless you create an intense RF field, which would also fry anyone trying to use the light.
You could build a tuned circuit to absorb the energy and transfer more power to the tube, but again once you calculate the required field energy you would not want to work in the vicinity of that field.
Again it all comes down to Lumens, and a 60 watt equivalent CFL draws about 14 watts or so from the line. At 85% or so efficiency for the converter, the lamp runs at about 12 watts to produce 900 Lumens @ 1 meter.
Now the questions I would put forward to the forum is this: How much local RF field strength is required one meter away from a CFL with or without a tuned circuit to produce 900 Lumens? Yes it will "light" with very small radiated power from an RF source but how many Lumens of useful light will be produced?
And if you crank up the power to the 900 Lumens@ 1 meter, would you want to live / work in a field with that much radiated energy?
You will find that it is most efficient to supply the energy directly to the tube with wires, so that none is lost radiating in other directions such as would happen with an RF ionizing field.
Sounds like the only thing engineered into CFL's is that you can't light them any other way.
The do indeed have to be designed in such a way as to minimize electrical interference - they're use in multiple settings where this interference could cause negative effects.
I think that a filament-free bulb might be the trick, something that could utilize the fact that they already have mercury vapor in them. Induction electrodes, perhaps? ...I'm thinking something that will not corrode when struck electrically?
I think I read somewhere that it's the heater filament's metal migrating into the area of plasma, and the subsequent failure of the chemically complex phosphor coatings that make them fail ( the bulb that is ) ballasts tend to go bad for their own reasons.
I, for a short time, thought that gas may be escaping. I didn't know there was a wire running their length? ..someone enlighten me.
Quote from: Gobaga on December 07, 2009, 09:48:55 PM
Is it possible to light fluorescent bulbs with a receiver attached to them or just the one wire like Tesla used?
One can light a fluorescent bulb standing next to a Tesla coil from the radiated magnetic field of the coil. Just hold the bulb close enough.
Without experimentation, however, I don't know how much better a wire connection would be.
--Lee
Quote from: Vortex1 on December 07, 2009, 08:19:15 PM
Forever is a long time.... Engineers do not speak in terms of forever
Free Energy engineers like to speak in terms of forever because that is afterall what we are looking for.....
Tesla basically invented the eternal CFL.
This was indeed a gas filled tube without electrodes that was placed in a strong RF field in theory it would emit light forever as long as the RF field is there.
However, these tubes also work on DC and in that case there is no RF component so there is no interference at all.
But there is offcource casscade, the electron bombardment which is responsible for the light it emits, this bombardement also impacts on the electrodes so they damage over time and this is why the tubes go bad.
It does not have to be that way because it is perfectly possible to ionize the gas through the glass by capacitive means.
There are some keys to be found in gas discharges because this is a situation where we have an opening for external power to enter our system.
Intresting things have been reported by several inventors that were looking into gas discharges, and particulary discharges where there is no vacuum arc.(full jump)
These reported overunity effects play in the regime just before the gas ignites into the vacuum arc discharge.
It is in the regime that is just below ignition and has a negative resistance.
We do not see these effects in normal tubes because the regime is too sharp, the tube will ignite instantly a good example of this is the flickering tube.
A chain reaction is hard to control..
Certain gasses are reported to have a wider pre discharge regime such as argone.
But the design of the tube aswell as the regulated supply to create the effect is quite hard to accomplish.
Marco.