On May 5, 10:38*am, Peter wrote:
I, and many others of my age, have played with mercury as a kid in the
1940s.
Rub it on a coin and it shined it up.
I'm not sure, but we might have even tasted it.
I remember busting the long florescent bulbs.
There is nothing wrong with me now.

Me too. Many times. *I think that my first few Gilbert chemistry sets
even contained a small vial of mercury. *I also played closely with a
"nuclear energy" set as a young teenager that included several sources
of alpha, beta, and gamma emitters. *I also probably fried my feet to a
crisp in the shoe store fluoroscopes in the early 1950s.

I'm in my mid-60s with no evidence of radiation damage or mercury
poisioning.

This is not to say that mercury and ionizing radiation are not
dangerous, or that what we did is safe. *But it seems that the current
hyperventilation over avoiding mercury levels that are only a small
fraction of what we experienced might be an over-reaction.

Not only that, but the increased power consumption of regular
incandescents over the consumption of CFLs causes the coal-burning
power station to emit more mercury.

On 5/5/2011 10:41 AM, Jim Yanik wrote:
wrote in news:ipu43o$g07$1@dont-
email.me:

On 5/4/2011 11:48 PM, hr(bob) wrote:
On May 4, 6:50 pm, wrote:
On 5/4/2011 3:55 PM, Larry Fishel wrote:

On May 4, 2:30 pm, wrote:
Googled this up at HD:

http://tinyurl.com/4xx897u

Interesting that the stated power consumption for this bulb is
actually HIGHER that for a 40W equivalent CFL...

A lot of light being wasted in a filter to improve the color?

I was wondering about that but had not looked up the comparison.
I don't know a lot about electronics but do know that LED's need direct
current so part of the extra energy may be in the AC/DC conversion.

I would worry about the color too. I had bought a couple of CFL's that
put out such white light that I could not use them indoors and had to
consign them to the front porch.

CFL lamps also require dc, they rectify the AC powerline ti dc, and
then run a high-frequency dc - ac converter tolight the lamp tube
itself. There is a large step-up in voltage needed to strike the
initial arc thru the tube, and the reduction in mercury reduces trhe
pressure in the tube until it heats up a little. Regular tubular
fluorescents contain appreciably more mercury than the cfl's do
because the arc lengthis mujch longer and the diameter of the tube is
much larger.

Did not know that. I do recall someone posting a diagram or picture of
internal electronics for a cfl and there was a lot of stuff in there.
Surprising that they can make them so cheap.


mercury is what provides the initial ions for current to flow across the
tube. it helps establish the arc.

I took apart a CFL and it only had two transistors,a tiny transformer,a
couple of electrolytic caps,2 diodes and some chip caps. It rectifies and
DOUBLES the input voltage,then converts to HF AC.


Next time one of mine burns out, I'll take it apart. The diagram I saw
looked complex for a light bulb. Sounds like what Wiki says:

Electronic ballasts contain a small circuit board with rectifiers, a
filter capacitor and usually two switching transistors connected as a
high-frequency resonant series DC to AC inverter. The resulting high
frequency, around 40 kHz or higher, is applied to the lamp tube.

Also noted of late, cfl's I've bought have been little hummers. Can't
recall in early ones. Maybe it's the cheap Walmart stuff I bought.

"Stormin Mormon" wrote in message ...

I have a 50,000 watt liberal finder, which I activate before
bedtime.

I'm sure you do, some folks have to find someone to blame whether it makes
sense or not.

"Stormin Mormon" wrote in news:ipug2v
:

I have a 50,000 watt liberal finder, which I activate before
bedtime.

I'll put on my tinfoil hat next time, before I ...

grin

--
Best regards
Han
email address is invalid

Excess regulation - sluggish economy
Printing lots of money - inflation
Deficit spending - lack of confidence

Seems sensible, to me.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"DGDevin" wrote in message
m...


"Stormin Mormon" wrote in message
...

I have a 50,000 watt liberal finder, which I activate
before
bedtime.

I'm sure you do, some folks have to find someone to blame
whether it makes
sense or not.

.......Visit Chris place?

Was that the end of the sentence?

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Han" wrote in message
...
"Stormin Mormon" wrote
in news:ipug2v
:

I have a 50,000 watt liberal finder, which I activate
before
bedtime.

I'll put on my tinfoil hat next time, before I ...

grin

--
Best regards
Han
email address is invalid

On 5/5/2011 9:41 AM, Jim Yanik wrote:
wrote in news:ipu43o$g07$1@dont-
email.me:

On 5/4/2011 11:48 PM, hr(bob) wrote:
On May 4, 6:50 pm, wrote:
On 5/4/2011 3:55 PM, Larry Fishel wrote:

On May 4, 2:30 pm, wrote:
Googled this up at HD:

http://tinyurl.com/4xx897u

Interesting that the stated power consumption for this bulb is
actually HIGHER that for a 40W equivalent CFL...

A lot of light being wasted in a filter to improve the color?

I was wondering about that but had not looked up the comparison.
I don't know a lot about electronics but do know that LED's need direct
current so part of the extra energy may be in the AC/DC conversion.

I would worry about the color too. I had bought a couple of CFL's that
put out such white light that I could not use them indoors and had to
consign them to the front porch.

CFL lamps also require dc, they rectify the AC powerline ti dc, and
then run a high-frequency dc - ac converter tolight the lamp tube
itself. There is a large step-up in voltage needed to strike the
initial arc thru the tube, and the reduction in mercury reduces trhe
pressure in the tube until it heats up a little. Regular tubular
fluorescents contain appreciably more mercury than the cfl's do
because the arc lengthis mujch longer and the diameter of the tube is
much larger.

Did not know that. I do recall someone posting a diagram or picture of
internal electronics for a cfl and there was a lot of stuff in there.
Surprising that they can make them so cheap.


mercury is what provides the initial ions for current to flow across the
tube. it helps establish the arc.

Like other fluorescents, the mercury is mostly liquid when the tube is
off. Starts on something more like argon. Heat from running vaporizes
the mercury (which is why they may not be full brightness at start). The
mercury arc produces a lot of UV, which the phosphors convert to visible
light.

Other than the orange neon color ones, "neon" lights work the same, with
cold (not heated) cathodes.


I took apart a CFL and it only had two transistors,a tiny transformer,a
couple of electrolytic caps,2 diodes and some chip caps. It rectifies and
DOUBLES the input voltage,then converts to HF AC.


Switch mode power supplies, like in a computer, seem to be winding up
everywhere.

--
bud--

In ,

Larry Fishel wrote:
On May 4, 2:30*pm, Frank wrote:
Googled this up at HD:

http://tinyurl.com/4xx897u

Interesting that the stated power consumption for this bulb is
actually HIGHER that for a 40W equivalent CFL...

A lot of light being wasted in a filter to improve the color?

According to the above link, this LED bulb consumes 8.6 watts to
produce 429 lumens (49.9 lumens/watt).

That is not much less efficient than a 40W-equiv. CFL, which produces
450-500 lumens from 9 watts (50-55.5 lumens/watt).

As for why this LED achieves about 50 lumens/watt while there are now
LEDs achieving 100-120 lumens/watt: I doubt the reason is filters:

1: My guess is that this LED bulb is a warm white one rather than a
cool white one. Warm white LEDs produce less green spectral content
and more red spectral content than cool white ones do. Not only is
human vision less sensitive to red than to green, but also phosphors
have higher "Stoke's loss" in producing red than in producing green
light from the same LED chip.

2: The LEDs in this bulb may be high color rendering index ones. There
is a recent trend for "warm white" LEDs used in lighting to have
color rendering index of at least 80. Cool white LEDs of extremely
high efficiency have CRI only 70 to low 70's, with some having
extreme lumen/watt phosphors only achieving CRI in the 60's.
Higher CRI requires the phosphor's spectral band to be wider,
to include a fair share of wavelengths from slightly bluish green
to mid-red. This is as opposed to a narrower phosphor band
concentrating on wavelengths from slightly yellowish green to
slightly orangish red. The wider band has more spectral content
at deeper red wavelengths that human vision is less sensitive to,
resulting in less lumens per watt.

3: The LEDs in this bulb may be less efficient than the most efficient
ones available of a given color and color rendering index. The
most efficient available LEDs have higher cost.

4: The LEDs in the LED bulb require a "ballast" or "driver circuit",
for similar reasons to the ones why a CFL requires a ballast
(included in usual screw-base CFLs). The ballast has some loss.
When a 120V AC-powered "LED driver" has 91 or 92% efficiency, that
is getting to be something to boast about. Merely fullwave-
rectifying 120 volts AC to DC has a loss around 1.5%.

--
- Don Klipstein )