I use "Stat-Les" anti-static floor finish on my benches.  You can find it at
Legge Systems,
http://www.leggesystems.com/c-177-static-control-floor-care-products.aspx
The price is pretty good for the 1 quart size bottles ($20 or so) and that
does a lot of benches.

-Bob, N3XKB

On Mon, Jan 25, 2010 at 8:42 AM, Brucekareen@aol.com wrote:

Bruce wrote:

I notice that many folks who have contributed on this thread use
anti-static benchtops, but I have never found it necessary (and I try
to keep the RH in my house under 45% -- it is generally 20% or less
in the winter).  I've been fooling with static-sensitive parts for 35
years and haven't lost one to static yet.  With that perspective, my
preferred benchtop is white Formica with a very, very slightly
pebbled surface.  Very durable, including to molten solder, and small
parts show up well.  I use rubberized "gunsmith" mats for preventing
scratches to delicate workpieces (these happen to be anti-static, but
that is not why I have them).

Other bench thoughts:

Bench depth is very important.  I sometimes work on equipment that is
more than 24" deep, so I want at least 30" of clear space in front of
any obstructions (power strips, Variac, test equipment,
whatever).  In the past, I used a "flying bridge" over the rear 18"
of a 48"-deep bench to elevate the test equipment, which worked very
well.  Now I use 24" deep adjustable wire-rack shelving units behind
a 30" benchtop (As others have pointed out, you can do the same with
equipment racks -- I'm not a fan of rack-mounting test equipment
unless the racks are anchored and everything is on slides, which I
was not prepared to do).  I don't have enough shop real estate to
have a permanent access aisle behind the test equipment, so the bench
and racks have large (5") locking polyurethane wheels and can be
pulled out relatively easily for reconfiguration.  This provides
plenty of stability for electronic projects, but you wouldn't want to
mount a big vise on the bench and try to bend 1" rebar.  For that, I
have a separate metalworking shop.

Bench height is also important.  I prefer a tall bench, suited to
working standing or sitting on an ergonomic stool, so my bench top is
44" above the floor -- a bit below my standing elbow height.

Finally, one can never have too many power outlets, or too much
light, in a workshop.  Lighting should be arranged so that it doesn't
cause specular reflections from the workpiece or the faces of test equipment.

Best regards,

Charles

In message 20100125182712.7014911B858@karen.lavabit.com, "Charles P. Steinmet
z" writes:

My worktable has a surface of hardwood-floor-boards and a painted
steel profile on the front that I make point out of touching before
sticking my fingers into any sensitive circuits.  Works for me.

--
Poul-Henning Kamp      | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG        | TCP/IP since RFC 956
FreeBSD committer      | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

Hi Charles,

I'm in a similar boat where I've worked with static sensitive parts without
any problems without having so much as put on a wrist strap.  It's just
never been an issue, even with our RH sitting around 12% here in New
Mexico.  I've been shoulder deep in Cray and SGI supercomputers without
worrying about it.  Then the day came where I needed to do surgery on my
network analyzer.  I figured the $20 for the coating was cheap insurance.  I
don't have $37k sitting around to replace it should I fry it.  That was the
first time I ever put on a wrist strap too!

-Bob

On Mon, Jan 25, 2010 at 11:27 AM, Charles P. Steinmetz <
charles_steinmetz@lavabit.com> wrote:

One generally looks for static-dissipative surfaces, rather than conductive surfaces. 1 Megohm/square, for instance.  The idea is to keep everything isopotential as charge drops onto things, not to rigorously establish a common voltage.

You haven't lost one that you know of. It also depends on the kinds of parts you're working with. There are some that are quite sensitive AND which don't fail outright, but just degrade performance a bit when they take a hit. It also depends on the energy behind the hit, of course.  An example might be the MiniCircuits ERA-4 or ERA-5 (just because I happen to have the data sheet handy).  Take a look at the later pages in the report, and you can see where the gain changes slightly as a result of 100V ESD hits (see page 6, where you can see gain dropping about 1.5 dB over 8 pulses, with about 0.1dB per hit.)

As they say at the end of the report:
The new amplifier ERA-4XSM shows gradual degradation in the gain and the
device voltage. That fact is not so bad. Even with the multiple stress a customer
would rather have gradual changes then catastrophic failure. The amplifier
withstands a single 100V ESD pulse, or 3 pulses at 50V.

http://www.minicircuits.com/pages/pdfs/an60028.pdf

When we (JPL) do site visits to vendors, lackadaisical approaches to ESD handling are one of the common problems. For us, who are building just one or two of something that's going to be going somewhere where repair isn't an option, latent damage and gradual degradation are a big deal.

It's really a "habit" thing that everyone has to get used to. That's why even nuts and bolts come in ESD packaging (even though they're obviously ESD immune): it gets people in the mindset of "come in the area, put on the wrist strap".  Back in the 70s, when ESD processes started to be used, they would have multiple categories of parts, some which needed ESD precautions (CMOS parts, DRAMs,etc.) and some which didn't (resistors, capacitors).  It was found that workers would be working with something in one category, and the habits would carry over to the others, so the industry, in general, went to the "everything is ESD sensitive" approach.

The worst offenders for ESD are the engineers (like those of us reading the list!), because they actually know what parts are sensitive and which aren't, and tend to take shortcuts with the non-sensitive parts.  Which works, sort of, until they guess wrong, and cook something.  "Hey, why is the NF on this LNA 0.2 dB higher than it was yesterday?"

jim

I've still got a paper copy of an HP Bench Brief from 1983 that was one
of my first introductions to the dangers of ESD.  I've used a wrist
strap and antistatic mat since then.  ESD protection in the ICs has
improved since then, but I think that the article is still mostly
applicable today.

http://www.hparchive.com/Bench_Briefs/HP-Bench-Briefs-1983-03-05.pdf

Ed

Lux, Jim (337C) wrote:

So looking at ESD mat material at Digikey, there appears to be a
bewildering array of choices.  Elastomer, rubber, vinyl,
thermoplastic, laminate, foam rubber, and polyethelene.

Any guidelines about what to choose?

Scott

On Jan 25, 2010, at 11:59 AM, Ed Palmer ed_palmer@sasktel.net wrote:

If you're in and out of ESD areas, then shoes with conductive soles are easier to use than always wrist strapping. Ditto if you're working on something big where the cord for the wrist strap gets in the way.  In some of our clean rooms, we have booties to go over your street shoes that have conductive coatings on them, and a conductive ribbon that you tuck into your sock to make contact.  (And you go stand on a test pad to make sure, of course).

I like the conductive shoes approach, it's pretty screw up proof, because you don't have to remember to plug your wrist strap in when you come to the bench, but the floor needs to be conductive, too.

These days, the black bins are dissipative and not marking.  The black foam is history (we all have ICs with corroded leads in the garage where the black foam turns to goo). Here at JPl, we don't use the pink bags/peanuts/stuff at all, because apparently, the coating can flake or rub off.  We use plastic that has a very thin metalized layer, and I think that's pretty much industry standard now.

And the megohm is important to keep you from inadvertently dying when you happen to accidentally contact the AC line.

Natural materials like wood, cotton, wool and even concrete have an
equilibrium
water content that changes with ambient relative humidity. This makes
these materials
conductive but not conductive enough to carry dangerous currents.
They are still good insulators
for mains voltage.
The textiles can change moisture content and conductivity quite
quickly
as they have fibre diameters of about 20 microns or so, but even at
20% RH static charges
dissipate in seconds. Plastics, however, tend to be very non-
conductive and charges
can be held for hours. Also, some plastics form electrets which stay
"charged" even under water.

A great insight to the static electricity problem came from articles
I read as a young boy in old (1910)
articles such as "make yourself an electrophorous" in popular science
mags.
A can lid was filled with melted resin. When solid it was rubbed with
wool. A metal
disk with insulated handle was placed on the resin and grounded with
a finger.
The disk was then lifted off the resin and would be found to have a
high charge (and voltage) on it.
(half inch fat spark to ground)
This process of induced charging and potential multiplication is the
danger on work benches.
The main way to overcome it is to have an isopotential environment
which naturally occurs with
natural materials where all charges rapidly drain away. Wood is good,
it does not produce charge
when rubbed and rapidly drains any charge away. And unless soaking
wet it will not electrocute you
if you are leaning on it when you touch and active power lead. (my
theory from experience is that
it is the ground that would kill you when if you were electrocuted.
If you have good soles on your shoes
and the other hand in your pocket an accidental touch to high voltage
is survivable)
just a few thoughts,
Neville Michie

Bill Hawkins wrote:

Your finger and hand makes a 700ps to 1 ns risetime device. Slew-rate
wise you can be up in several milions of V/us. The arm has sufficient
induction that it takes a considerable time before the body discharges,
but the hand creats the leader and then the big blow comes from the body
discharge. Just as a cloud and a ligthning bolt, but in man-size.

However, being ESD aware does not mean going maniac about it. It's more
like don't finger on things which is very hot. You need to build good
habits to avoid doing something bad.

Cheers,
Magnus

Lux, Jim (337C) wrote:

The first greeting a new collueage gets when comming first day to work
is "What shoesize are you?". We order ESD shoes for more or less
everyone. Our US sales-people is known to ask if it is real Birkenstock
shoes. :)

This is why you guys don't have a pink-day at the office! :)

You got to have a silly pink-day every once in a while just for the fun
of it. I'll see if not the HW department can adapt it, as they have
tried non-casual-friday (usual dress code is... um... casual).

There is a reason for EKG equipment being measured for isolation
properties. The medical staff wants to select the time and dosage of
larger currents through the heart, and preference is towards patients
that badly need it.

Cheers,
Magnus

Back about 1981, we had piles of 6502s, etc and decide to some "antistatic testing". We put a 40pin ZIF socket into a VIC-20, and then set about trying to fry the uP using carpet, a cat, car seats, etc. The DUT was then put back into the VIC and series of tests run to verify operation. I don't think we ever had a failure. Of course, there may have been some hiding that we missed, but all the static damage I've seen has been pretty severe.

That said, I always use a wrist strap and mat if I'm working on something I don't want to break further.

-Dave
----- Original Message -----
From: "Charles P. Steinmetz" charles_steinmetz@lavabit.com
To: "Discussion of precise time and frequency measurement" time-nuts@febo.com
Sent: Monday, January 25, 2010 11:27:11 AM GMT -07:00 US/Canada Mountain
Subject: Re: [time-nuts] Conducting Bench Top Material

Bruce wrote:

I notice that many folks who have contributed on this thread use
anti-static benchtops, but I have never found it necessary (and I try
to keep the RH in my house under 45% -- it is generally 20% or less
in the winter). I've been fooling with static-sensitive parts for 35
years and haven't lost one to static yet. With that perspective, my
preferred benchtop is white Formica with a very, very slightly
pebbled surface. Very durable, including to molten solder, and small
parts show up well. I use rubberized "gunsmith" mats for preventing
scratches to delicate workpieces (these happen to be anti-static, but
that is not why I have them).

Other bench thoughts:

Bench depth is very important. I sometimes work on equipment that is
more than 24" deep, so I want at least 30" of clear space in front of
any obstructions (power strips, Variac, test equipment,
whatever). In the past, I used a "flying bridge" over the rear 18"
of a 48"-deep bench to elevate the test equipment, which worked very
well. Now I use 24" deep adjustable wire-rack shelving units behind
a 30" benchtop (As others have pointed out, you can do the same with
equipment racks -- I'm not a fan of rack-mounting test equipment
unless the racks are anchored and everything is on slides, which I
was not prepared to do). I don't have enough shop real estate to
have a permanent access aisle behind the test equipment, so the bench
and racks have large (5") locking polyurethane wheels and can be
pulled out relatively easily for reconfiguration. This provides
plenty of stability for electronic projects, but you wouldn't want to
mount a big vise on the bench and try to bend 1" rebar. For that, I
have a separate metalworking shop.

Bench height is also important. I prefer a tall bench, suited to
working standing or sitting on an ergonomic stool, so my bench top is
44" above the floor -- a bit below my standing elbow height.

Finally, one can never have too many power outlets, or too much
light, in a workshop. Lighting should be arranged so that it doesn't
cause specular reflections from the workpiece or the faces of test equipment.

Best regards,

Charles

time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Hi

If you are manually loading up a wire bonder with conventional CMOS chips, ESD damage is a very real thing. You can haul the chip over to a SEM and actually take pictures of he craters you blast in it. Very cool pictures. No cat's, carpets, or Windhurst machines needed.  Just normal operators with missing wrist straps will do the trick quite nicely.

Bob

On Jan 26, 2010, at 2:21 AM, d.seiter@comcast.net wrote:

These days it's not just semiconductors at risk given the tiny geometry of
passives.  At work we had a work station where we assembled a board with
all passive components, so no thought was given to ESD control.  We traced
a series of mysterious failures to ESD affecting the value of some
resistors.  Now ESD control is just about everywhere!

-Joe Fitzgerald KM1P

Everything old is new again.

The 25+ year old HP Bench Brief that I referred to a few messages back
warns about that.

Ed

Joe Fitzgerald wrote:

Ed Palmer wrote:

"Nothing usefull could be found in old documents, they just didn't have
the same technology as we have, and hence not the problems." Well, not
that much different. Scale is the main thing. People have been studying
all kinds of things, so good clues may still lay around if you dare look
for them.

Thanks for remembering this stuff.

Cheers,
Magnus

Wasn't life so much easier with valves (tubes)...

:-)

Steve

2010/1/27 Bob Camp lists@cq.nu:

--
Steve Rooke - ZL3TUV & G8KVD
A man with one clock knows what time it is;
A man with two clocks is never quite sure.

Steve wrote.

Wasn't life so much easier with valves (tubes)...

Amen brother.

Regards.

Max.  K 4 O D S.

Email: max@maxsmusicplace.com

Transistor site http://www.funwithtransistors.net
Vacuum tube site: http://www.funwithtubes.net
Music site: http://www.maxsmusicplace.com

To subscribe to the fun with transistors group send an email to.
funwithtransistors-subscribe@yahoogroups.com

To subscribe to the fun with tubes group send an email to,
funwithtubes-subscribe@yahoogroups.com

----- Original Message -----
From: "Steve Rooke" sar10538@gmail.com
To: "Discussion of precise time and frequency measurement"
time-nuts@febo.com
Sent: Wednesday, January 27, 2010 8:23 PM
Subject: Re: [time-nuts] Conducting Bench Top Material

Wasn't life so much easier with valves (tubes)...

:-)

Steve

2010/1/27 Bob Camp lists@cq.nu:

--
Steve Rooke - ZL3TUV & G8KVD
A man with one clock knows what time it is;
A man with two clocks is never quite sure.

time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 8.5.432 / Virus Database: 271.1.1/2650 - Release Date: 01/27/10
19:36:00

Steve Rooke wrote:

Nostalgia?

Valves (tubes) warmer in close proximity, yes. Global warming should
make that, on average, less helpful.

In the 60's listening to rock music, I could look at the final tubes in
a dark room and see the purple glow inside dance with the music.
Anyone else?
Solid state amps just can't do that. Way cool. I never tried it with
cannabis, but probably even better.

Other than that memory, and certain trade-offs at big Rf power, I'll say
I no longer encourage the glowing bulbs for most things.

And at least I can drop a transistor on the floor without too much damage ;-)
 
Robert G8RPI.

--- On Thu, 28/1/10, Rex rexa@sonic.net wrote:

From: Rex rexa@sonic.net
Subject: Re: [time-nuts] Conducting Bench Top Material
To: "Discussion of precise time and frequency measurement" time-nuts@febo.com
Date: Thursday, 28 January, 2010, 5:50

Steve Rooke wrote:

Nostalgia?

Valves (tubes) warmer in close proximity, yes. Global warming should make that, on average, less helpful.

In the 60's listening to rock music, I could look at the final tubes in a dark room and see the purple glow inside dance with the music.
Anyone else?
Solid state amps just can't do that. Way cool. I never tried it with cannabis, but probably even better.

Other than that memory, and certain trade-offs at big Rf power, I'll say I no longer encourage the glowing bulbs for most things.

time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

And no-one ever invented complimentary N channel and P channel valves
(tubes).
And they had a service life of 5000 hours and they stoppd working
properly.

On 28/01/2010, at 6:51 PM, Robert Atkinson wrote:

Warning: Way OT

When the vacuum tube was born, there were half as many people on
this planet, and global climate change wasn't a problem. Very few
people will talk about populution. It's as if there was a blind
spot in the brain. Maybe there's no intelligent life in the
Universe because all life evolves with similar selection pressures.
Once technology removes natural predators (or stops world wars with
the atomic bomb), population heads for the sky until the big die-off.

If other people don't have a problem with having four kids, I have
no problem with using vacuum tubes and Edison bulbs.

All in my humble opinion, of course.

Bill Hawkins

-----Original Message-----
From: Rex
Sent: Wednesday, January 27, 2010 11:50 PM

Steve Rooke wrote:

Nostalgia?

Valves (tubes) warmer in close proximity, yes. Global warming should
make that, on average, less helpful.
........
glowing bulbs
Other than that memory, and certain trade-offs at big Rf power, I'll say
I no longer encourage the glowing bulbs for most things.

In message 924780D899C84029950F3D9CAEE28054@cyrus, "Bill Hawkins" writes:

No, the blind spot is making a big issue out of population control
in countries where the environmental footprint per person is virtually
nill essential zero, in order to obscure the fact that approx 1% of
the population of the planet is responsible for 99.99% of our
problems, environmental or otherwise.

Poul-Henning

--
Poul-Henning Kamp      | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG        | TCP/IP since RFC 956
FreeBSD committer      | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

Hi

If we ever go back to tubes we're going to have a bunch of tech's knocked out on the floor. Nobody has a clue about high voltage any more. You had to have a good respect for it on a tube circuit or you got in big trouble.

Bob

On Jan 27, 2010, at 9:23 PM, Steve Rooke wrote:

2010/1/28 Bill Hawkins bill@iaxs.net:

True, but I can never recall having a problem with ESD with them
(which was the current topic of the thread).

Steve

Steve Rooke - ZL3TUV & G8KVD
A man with one clock knows what time it is;
A man with two clocks is never quite sure.

2010/1/28 Rex rexa@sonic.net:

Nostalgia ain't what it used to be!

And we heated our houses less.

Way, way back I was listening in the background to an old Teak amp one
day when I thought that it sounded a bit distorted. Went over to look
at the chassis and saw one of the valves in the output stage with it's
anode glowing red! Hmmm, seems it was conducting just a little more
than it was supposed to do due to a biasing component failure. A
couple of minutes later and some work with a soldering iron and the
sound was fine again. That chassis went on forever on that same valve.

They soon go legs up if you apply too much voltage or current which
valves would just shrug off.

They certainly still held their own in high power RF stages but I
wouldn't go out of my way to build something out of them now.

As for conductive surfaces for benches and the like, RS Components
used to sell a static conducting matting by the square yard that you
could order. It was a yellow and about 1/8" thick flexible dense
rubberized material. We covered our benches and floor around our
workplaces and had the press-stud fittings riveted to them so you
could clip your earthing strap to it. It was very hard waring and
coped well with molten solder dripping onto it. I believe I still have
a sheet of it somewhere in the garage.

73
Steve

Steve Rooke - ZL3TUV & G8KVD
A man with one clock knows what time it is;
A man with two clocks is never quite sure.

2010/1/28 Neville Michie namichie@gmail.com:

True but they did come up with a lot of designs involving multiple
grids etc which allowed a single valve to perform more complex
functions. Remember the old magic-eye indicators, triodes and pentodes
in the same envelope, mixers, etc.

And they were easy to fault-find, and replacement was a breeze.

I'm too far off topic now, sorry to hi-jack the thread.

Steve

Steve Rooke - ZL3TUV & G8KVD
A man with one clock knows what time it is;
A man with two clocks is never quite sure.

2010/1/29 Bob Camp lists@cq.nu:

Remember the valves that used to have the grid at the top of the
envelope via a separate connection. That made it real easy to inject a
signal for tracing through the circuit, you just put your finger on it
and listened for mains hum at the speaker, for instance. hat was
alright till you found the valve that had an anode at the top...

That's going back a looong way.

Steve

Steve Rooke - ZL3TUV & G8KVD
A man with one clock knows what time it is;
A man with two clocks is never quite sure.

And now "they" are trying to do away with edison bulbs. I hope the LED equivalents are better, because the CF bulbs seem to last less in most home apps. (I have "standard" bulbs that have outlasted multiple CF bulbs in similar applications) In particular, I have a 75W desk lamp bulb which has been in use since '97 and gets more hours than the ceiling CFs in the same room, which have been replaced at least 3 times...

They are not enclosed or abused. I was really PO'd at the short life of my first set of CF lamps. They seem to be doing better now, but still there is no great enhanced life span.

Dave
----- Original Message -----
From: "Bill Hawkins" bill@iaxs.net
To: "Discussion of precise time and frequency measurement" time-nuts@febo.com
Sent: Thursday, January 28, 2010 2:28:31 AM GMT -07:00 US/Canada Mountain
Subject: Re: [time-nuts] Conducting Bench Top Material

Warning: Way OT

When the vacuum tube was born, there were half as many people on
this planet, and global climate change wasn't a problem. Very few
people will talk about populution. It's as if there was a blind
spot in the brain. Maybe there's no intelligent life in the
Universe because all life evolves with similar selection pressures.
Once technology removes natural predators (or stops world wars with
the atomic bomb), population heads for the sky until the big die-off.

If other people don't have a problem with having four kids, I have
no problem with using vacuum tubes and Edison bulbs.

All in my humble opinion, of course.

Bill Hawkins

-----Original Message-----
From: Rex
Sent: Wednesday, January 27, 2010 11:50 PM

Steve Rooke wrote:

Nostalgia?

Valves (tubes) warmer in close proximity, yes. Global warming should
make that, on average, less helpful.
........
glowing bulbs
Other than that memory, and certain trade-offs at big Rf power, I'll say
I no longer encourage the glowing bulbs for most things.

time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Hi

At least down here the CF lamps seem to run at least 2X and probably more than that compared to the old style bulbs. There are 20 of them in this room so that's a pretty good sample.

The big thing I notice is that the room does not self heat as much with 1/10th the power going into it. Right now a little self heating might be nice. Not so much so in the summer ....

The only issue I've seen is that they don't seem to like tightly enclosed fixtures very much. They seem to need a much lower temperature at the base than an old style bulb. In a can light, or most open fixtures that's not an problem. In some covered / enclosed celling fixtures they don't seem to get the cooling they need.

Bob

On Jan 29, 2010, at 2:32 AM, d.seiter@comcast.net wrote:

In message 6755CB2A-9566-4F35-818E-38471BE6528F@cq.nu, Bob Camp writes:

Speaking of LED lamps: I want to point out that at least over here
IKEA has a wonderful little LED lamp for the worktable.

It's a single 3W white led, at the end of a 55cm long (that's 20" for
the imperialists amongst us) "swan-neck".

I use one for my small CNC-mill:

http://ing.dk/uploads/society/content/232.png

It's called "JAN SJÖ" here, not sure if they use that name in other
geographies.

Highly recommended.

--
Poul-Henning Kamp      | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG        | TCP/IP since RFC 956
FreeBSD committer      | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

The most important thing to remember about CFLs is don't use them
anywhere that they will be turned on and off a lot (e.g. bathrooms).
Use them where they'll be turned on and left on.  Short on / off cycles
can reduce their lifetime to 15% of normal.  Here's a report on the
subject:

http://www.lrc.rpi.edu/nlpip/publicationDetails.asp?id=114&type=1

Ed

d.seiter@comcast.net wrote:

Hi Poul:

Can the base be hung on a wall?
http://www.ikea.com/us/en/catalog/products/10128734

Have Fun,

Brooke Clarke
http://www.PRC68.com

Poul-Henning Kamp wrote:

In message 4B631407.9090305@pacific.net, Brooke Clarke writes:

The base is a lump of metal

But the swan-neck is just screwed into the base (some assembly :-)
so if you are comfortable with cutting the wire and splicing it
again, you can mount it on anything you can drill a 10mm hole in...

--
Poul-Henning Kamp      | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG        | TCP/IP since RFC 956
FreeBSD committer      | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

Hi

But wouldn't cutting and splicing the wire void the warranty and possibly
thus lead to the end of civilization as we know it....

Where is the AC to DC conversion done? In a lot of these it's in the base.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Poul-Henning Kamp
Sent: Friday, January 29, 2010 12:07 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] [OT] Ikea Lamp

In message 4B631407.9090305@pacific.net, Brooke Clarke writes:

The base is a lump of metal

But the swan-neck is just screwed into the base (some assembly :-)
so if you are comfortable with cutting the wire and splicing it
again, you can mount it on anything you can drill a 10mm hole in...

--
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In message E580BC8AE64F443288DA889E7EA5CE17@vectron.com, "Bob Camp" writes:

In the tiny wall-wart.

--
Poul-Henning Kamp      | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG        | TCP/IP since RFC 956
FreeBSD committer      | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

I've heard you can salvage some good rectifiers and maybe a transistor or
two from dead CF bulbs.

Regards.

Max.  K 4 O D S.

Email: max@maxsmusicplace.com

Transistor site http://www.funwithtransistors.net
Vacuum tube site: http://www.funwithtubes.net
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----- Original Message -----
From: d.seiter@comcast.net
To: "Discussion of precise time and frequency measurement"
time-nuts@febo.com
Sent: Friday, January 29, 2010 1:32 AM
Subject: Re: [time-nuts] Conducting Bench Top Material

No virus found in this incoming message.
Checked by AVG - www.avg.com
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19:36:00

There are multiple versions, including wall-mount and one that clamps onto
the edge of an object like a bookshelf.  Here is the family:

http://www.ikea.com/us/en/search/?query=jansjo

They all probably have the same LED head.  If you don't need a long
gooseneck, the wall and clamp versions are the cheapest way to get the head
plus a short gooseneck.  They give a circle of light with a fairly sharp
cutoff at the edge of the circle.  Think of it as something that will fit
into many of the places where you would really like to have a fiber optic
light source, but at 1/5 the cost.

The little wall wart is a regulated constant-current supply (not constant
voltage), which ought to make the light output relatively constant despite
LED temperature changes and wire resistance changes.  However, I find that
the cheap inline switch has contacts that tend to get dirty or oxidize, and
the LED flickers until I flip the switch on and off a couple of times to
clean the contacts.  If you're going to modify it anyway, install a better
switch.

I have two of these.  One clamp-base is mounted on my computer desk, up
high, where it illuminates my keyboard without washing out the monitor.  The
other has the weighted desk base, and it's useful as a reading lamp as well
as illuminating things under the stereomicroscope, and looking inside
cluttered equipment chassis.

  Dave

On Fri, Jan 29, 2010 at 8:59 AM, Brooke Clarke brooke@pacific.net wrote:

Hi David:

Thanks for the link.  I like them.  The only problem is that you can not
order on line or by phone from Ikea and the nearest store is over two
hours drive away.

Have Fun,

Brooke Clarke
http://www.PRC68.com

David Martindale wrote:

Poul-Henning Kamp wrote:

LED lamps... the one thing I keep being annoyed about is the aspect of
having three peaks of relative narrow spectrums rather than the normal
continuous spectrum mainly being that of the temperature signature.

Anyone out there looking at the frequency spectrum of these low-energy
lamps?

Colour response from few-spike lamps is not really the same than from
continuous spectrums.

IKEA has a habit of giving all their products Swedish names for their
products... worldwide. It's part of their trademark so to speak.

Cheers,
Magnus

Attached is a spectrum of a "white" LED Flashlight. My diode spectrometer
does not go further than the limits shown.

Best,
-John

===============

Hi John:

Would you mention the make and model number of the SA and LED?

Have Fun,

Brooke Clarke
http://www.PRC68.com

J. Forster wrote:

J. Forster wrote:

Looks pretty continuous to me. Great. I know there is non-continuous
LEDs out there, but I hope they will fade to grey while continuous takes
the market.

Cheers,
Magnus

To my aging eyes, the flashlight looks distinctly blue-white. I don't know
how these particular LEDs are built, but the unit is less than a year old.

-John

===============

On Fri, Jan 29, 2010 at 05:15:51PM -0800, J. Forster wrote:

My understanding is that a lot of high brightness "white" LEDs 

are internally a UV emitting LED junction illuminating a phosphor.  The
light you see comes mostly from the phosphor.

Lighting type phosphors have been around forever in fluorescent

bulbs... and are fairly continuous spectra mostly...

I don't think there is any way of getting broadband white light

out of a LED junction, though of course hybrids of multiple different
color LEDs can be used (and are in the display business).

--
Dave Emery N1PRE/AE, die@dieconsulting.com  DIE Consulting, Weston, Mass 02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole - in
celebration of what could have been, but wasn't and is not to be now either."

The LED lamps that I have seen use UV LED's with a fluorescent material
in the LED to make it appear white.  I don't know what the spectrum looks
like, but to my eye it appears to be pretty white.

-Chuck Harris

Magnus Danielson wrote:

also matches the sun within reason...
Don
----- Original Message -----
From: "Magnus Danielson" magnus@rubidium.dyndns.org
To: jfor@quik.com; "Discussion of precise time and frequency measurement"
time-nuts@febo.com
Sent: Friday, January 29, 2010 6:12 PM
Subject: Re: [time-nuts] Conducting Bench Top Material

I took apart the last dead one just for that purpose. I initially eyed the 105deg Al cap, but it was dead, along with one of the xstrs (hole in package). The film caps, diodes and fuse are still good too. As is the tube- don't know what I'll do with that.

-Dave
----- Original Message -----
From: "Max Robinson" max@maxsmusicplace.com
To: "Discussion of precise time and frequency measurement" time-nuts@febo.com
Sent: Friday, January 29, 2010 12:39:25 PM GMT -07:00 US/Canada Mountain
Subject: Re: [time-nuts] Conducting Bench Top Material

I've heard you can salvage some good rectifiers and maybe a transistor or
two from dead CF bulbs.

Regards.

Max. K 4 O D S.

Email: max@maxsmusicplace.com

Transistor site http://www.funwithtransistors.net
Vacuum tube site: http://www.funwithtubes.net
Music site: http://www.maxsmusicplace.com

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----- Original Message -----
From: d.seiter@comcast.net
To: "Discussion of precise time and frequency measurement"
time-nuts@febo.com
Sent: Friday, January 29, 2010 1:32 AM
Subject: Re: [time-nuts] Conducting Bench Top Material

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19:36:00

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Hi,I'm late to the thread (as usual), but have looked at these LED's in the past. It was for a biotech imaging application. There are two types, a red/green/blue cluster or a blue / near UV LED with a white phosphor. These phosphors seem to have a fairly continuous spectrum, at least compared to fluorescent lamps and HID lamps. What surprised me was the speed. We had a strobe application for which a xenon strobe was proposed. I tried LED's (our optics "expert" said even normal LED's would not be fast enough). I knew normal LED's are fast enough but was unsure about the phosphor types. To my surprise they where faster than the xenon tube! They were faster than my detector. This has has an impact on the mill illumination in that you can get strobe effects that could cause you to think the spindle was stationary when it was not. This is more of a problem in a noisy environment than a home shop with only one machine running.  
Robert G8RPI.

--- On Sat, 30/1/10, J. Forster jfor@quik.com wrote:

From: J. Forster jfor@quik.com
Subject: Re: [time-nuts] Conducting Bench Top Material
To: "Magnus Danielson" magnus@rubidium.dyndns.org
Cc: "Discussion of precise time and frequency measurement" time-nuts@febo.com
Date: Saturday, 30 January, 2010, 1:15

To my aging eyes, the flashlight looks distinctly blue-white. I don't know
how these particular LEDs are built, but the unit is less than a year old.

-John

===============

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The speed isn't  terribly surprising since the "phosphor" used  is
actually a scintillator.
Unlike phosphors scintillators don't have long decay times so there is
no afterglow like that from a phosphor.

The IKEA LED lamp output may not be significantly modulated if the wall
wart constant current supply may have an output thats a little smoother
than just rectified AC.

Bruce

Robert Atkinson wrote:

Yes, it is frustrating, they have to be the last dinosaurs of consumer
distribution.

For me, the nearest store is 6 hours away, if I don't get stopped for a
speeding ticket on the way...
So I can't afford to be interested in what they may have for sale.

Didier

Don Latham wrote:

Indeed.

Cheers,
Magnus

d.seiter@comcast.net wrote:

Sounds to me that the electronics died... rather than the bulb.

Cheers,
Magnus

Also they are very sensitive to heat, so do not use them in an enclosed
fixture.

I have been burned (figuratively) with these two gotchas, there may be more.
The one that lasts the longest in my house is the outside light at my back
door. It is turned on once a day around 6-7 PM and off in the morning, so
about 12 hours a day every day, and it lasts for years at that rate. Those
in the bathroom that get to be turned on and off several times a day for a
relatively short time don't do nearly as well.

Didier

Hi

At the cost target on those bulb's it's always a race to see who dies first.

The same can be said of conventional fluorescent fixtures. I have some big ones in the shop downstairs. The no name electronic ballasts that came with them all died in the first two years. I replaced them with name brand parts and they have run fine ever since (at least 3 years so far). All the fixtures are on their first set of bulbs.

Bob

On Jan 30, 2010, at 8:26 AM, Magnus Danielson wrote:

I bought some of the LED replacements for Edison bulb incandescents, and
they have an afterglow that lasts for several minutes.  It is very much
dimmer than when they are turned on, but is there none the less.

-Chuck

Bruce Griffiths wrote:

I have dissected many dead CFL's, and the key component failure
is the 10uf 350V electrolytic capacitor.  Most of these bulbs caution
against using them in a base up configuration.... which of course is
how most of my CFL's are operated.

I have several rooms that are lit exclusively with CFL's, and I find
that for best life, I have to leave them on all the time.  That is what
EPA has found too!  CFL's may take less power for a given illumination,
but the owners leave them on far longer than incandescent, and the net
result is greater power consumption overall.

Add that to the mandatory drop of mercury in each, and I really can't
see how they can sell them at all.

I got two for "free" from my power company (They hid the charge on my
bill, until the courts made them reverse it...) and included with the
CFL's was an elaborate procedure for cleaning up a broken CFL.  It involved
opening all of the windows, and leaving the room for a couple of hours,
and then, with a gloved hand putting the pieces on newspaper, and folding
the newspaper up and putting it in a 1 gallon zip lock baggie.  To clean up
the broken bits, you are supposed to vacuum the area with a fresh vacuum
cleaner bag, and then put the vacuum cleaner bag in a ziplock baggie, and
take the remains off to the hazardous waste disposal facility.

-Chuck Harris

Magnus Danielson wrote:

IKEA and $39 per lamp. Sounds like some pretty good margin in the sale.
I guess these LED things will be main stream and save the world when we see
them at walmart for $6.

On my bench I converted to 60 watt halogen lamps compared to the 100 watt
lamp.
Equivalent color spectrum to the traditional lamp also. For as many hours as
that light is on. I suspect I am saving some money in the long run.

Curious are these lights truly white or do they tend towards a traditional
lamp spectrum.
Regards

On Sat, Jan 30, 2010 at 8:15 AM, Didier Juges didier@cox.net wrote:

Hi

I have a store some 5km away... but anyway, it seems its possible to
webshop at least in Ikealand.

http://www.ikea.com/ms/sv_SE/customer_service/how_to_e-shop/how_to_e-shop.html

--

Björn

For those who don't speak swedish try:

<http://www.ikea.com/ms/en_GB/customer_service/how_to_e-shop/how_to_e-shop.h
tml>

Dave

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of bg@lysator.liu.se
Sent: 30 January 2010 16:01
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] [OT] Ikea Lamp

Hi

I have a store some 5km away... but anyway, it seems its possible to webshop
at least in Ikealand.

http://www.ikea.com/ms/sv_SE/customer_service/how_to_e-shop/how_to_e-shop.ht
ml

--

Björn

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Robert Atkinson wrote:

Traditional LEDs might not be optimized for speed, bug being GaAsP based
they are probably not too shabby. InP and other fun (and fast) materials
is used. Digging up on LEDs led me over YAG to bubble memories.

Interesting side-effects of this discussion is that one learns more in
fields one does not ponder too much over normally.

Cheers,
Magnus

Chuck Harris wrote:

I got one of these so called 2D fluorescent tubes in a packet and bought it home
on the train late in the evening. The trains are electric with cables overhead.
What was strange was that the lamp was glowing dimly in the packet - I can only
assume the E field from the overhead cables for the train was the source of power.

Dave

Dr. David Kirkby wrote:

I should have added, it carried on glowing for some time after I got home too.
At that point, I was well away from the train lines, though we do have 11 kV
overhead cables around 30m from the house. It eventually stopped glowing so I
assume it was the presence of the overhead train lines which caused this.

Hi Paul:

LEDs come in many flavors of white.  The ones called warm white can be
very comfortable but they are not as bright as the plain white or cool
white LEDs.

Also high power LEDs can burn your eye.  Not because they emit UV but
rather just because they are bright, like the Sun.
http://www.prc68.com/I/LED.shtml#Atlas  This is a 7 Watt LED that burned
my eyes.

Wien's displacement law relates the wavelength emitted from a hot body
to it's surface temperature.  For numbers for the Sun or a human see:
http://www.prc68.com/I/Probeye.shtml#WaT
Planck's law took another five years to relate frequency and surface temp.

Have Fun,

Brooke Clarke
http://www.PRC68.com

paul swed wrote:

Or, possibly, your radiant personality :). - Mike

Mike B. Feher, N4FS
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Dr. David Kirkby
Sent: Saturday, January 30, 2010 12:47 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] White LED's

Dr. David Kirkby wrote:

I should have added, it carried on glowing for some time after I got home
too.
At that point, I was well away from the train lines, though we do have 11 kV

overhead cables around 30m from the house. It eventually stopped glowing so
I
assume it was the presence of the overhead train lines which caused this.

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Clarke
Sorry to hear that you hurt your eyes. I suspect many are unaware of the
risk.
I have experimented with higher power LEDs but nothing like 7 watts so very
good to have learned something. I have to say even looking at the lower
power LEDs you get the feeling that looking straight on is not a good idea.

My wife used some of the new LEDs on a christmas tree this year. We didn't
like them and turned them off using just the traditional lamps. She now
understands what a point source is.
Also if straight on they were quite bright off angle 12 degrees they were
pretty dim.

I have tinkered for a while looking for effectively spread leds for panel
meters. I dislike changing lights in my radios. But the LED simply do not
spread light the way lamps do.

Like your idea of the flexible trouble light.

On Sat, Jan 30, 2010 at 12:55 PM, Brooke Clarke brooke@pacific.net wrote:

Dr. David Kirkby wrote:

When I was a kid, there was a main set of high tension power lines several
hundred yards from my house.  I had friends that had garden sheds under the
towers that were lit by fluorescent lamps collecting the stray fields.  A
piece of wire on each end of the bulb enhanced the effect.

I knew of one guy that had a big coil of wire in the roof of his shed
and he could light a 100W incandescent bulb from the stray fields.

-Chuck Harris

If you care about accurate colour rendering, stick with incandescent,
preferably halogen.  "White" LEDs are actually blue LEDs coated with a
phosphor that absorbs some of the blue light and emits approximately
yellow instead.  If you look at the spectrum, you'll see a broad yellow
peak and a narrower blue peak.  Your eyes see it as approximately white,
but it's deficient in red and green compared to a black body emitter
like hot tungsten.  On the other hand, it's not as spiky as the output
of fluorescents.

The particular IKEA units I have both look approximately "daylight" in
colour temperature, and the colour is pretty uniform across the
illuminated field (except for the very edge, which is yellow, but that's
probably due to chromatic aberration in the lens, not the LED source).
They work better than most of the LED flashlights I've seen, which tend
to have large intensity and colour changes between the centre and the
edge of the illuminated field.

 Dave

On 30/01/2010 07:49, paul swed wrote:

Hmm.  Has anyone built a strobe light using LEDs instead of a xenon
flash tube?  I can see the appeal of building something that doesn't
need high voltage to fire or trigger the tube.  Yes, you probably
couldn't get as much light as a big Xenon tube, but there are
applications where you don't need to illuminate a large area.  (Recent
example of where I wished I had a stroboscope: looking at the balance
wheel of a pocket watch).

How high can you push the drive current of a LED if the pulse is short?
Of course you have to keep the average dissipation below what the device
is rated for, but there must be a peak current limit too.

 Dave

On 30/01/2010 01:17, Robert Atkinson wrote:

I have some Philips LED halogen downlighter replacements. They are rated at 3W and produce a noticeable glow when "OFF". They are on a 2-way circuit and the stray capacitance of the wiring allows enough current for a faint glow.
Robert G8RPI. 

--- On Sat, 30/1/10, Chuck Harris cfharris@erols.com wrote:

From: Chuck Harris cfharris@erols.com
Subject: Re: [time-nuts] White LED's
To: "Discussion of precise time and frequency measurement" time-nuts@febo.com
Date: Saturday, 30 January, 2010, 14:27

I bought some of the LED replacements for Edison bulb incandescents, and
they have an afterglow that lasts for several minutes.  It is very much
dimmer than when they are turned on, but is there none the less.

-Chuck

Bruce Griffiths wrote:

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There are also large differences in rated lifetime; look at the fine
print on the package.

I've had some early Philips units that I used in a timer-driven lamp;
they were on for hours every day.  The lamp lasted for years and years
and I eventually threw it out because it had gotten dim (the tube was
visibly blackened inside), but it was still working.  It was rated for
10000 hours, and probably reached that before I junked it.

On the other hand, I've had some cheap Ikea lamps fail in ceiling lights
in little more than a year.  The electronics self-destructed.  Took a
close look at the package for a new one, and they are rated for only
2000 hours - which is easy to use up in a year in a room where the
lights are on 6 hours every evening.

Now, using CFLs of any type reduces electricity use compared to
incandescent, and that's worthwhile in many applications.  But CFLs also
add a bunch of electronics parts to the waste stream when they are
thrown out - they're much worse than incandescents in that respect.  So
when I use fluorescents, I prefer replaceable-tube units (where the
electronics in the ballast will last for decades, not be replaced every
couple of years).  In places where I need a screw-in self-ballast type,
I look for the more expensive 10,000 hour types instead of the cheap
2000-hour ones.

And, as someone else pointed out, it doesn't make much sense to use CFLs
in applications where they are turned on and off a lot, since their life
will be much shorter than rated.  (But LEDs should be fine for this,
once the price comes down a bunch).

 Dave

On 30/01/2010 05:31, Didier Juges wrote:

Hi Dave,Yes I have. There was also a design in Nuts&Volts a while back. Generally if you keep the duty cycle low  (<1:20) and pulses short (<20ms) you can push most LED's to about ten times their maximum continuous rated current without ill effect. Looking at the continuous and pulse ratings of IR LED's can give an idea of the "abuse" LED's can handle. Some small white LEDs do have pulse specifications, they are used as the flash in cell phone cameras.  They make very good small strobes with much less "tail" than the $200 miniature Hamamatsu xenon tubes we were comparing them to. 
Robert.G8RPI.

--- On Sat, 30/1/10, Dave Martindale dave.martindale@gmail.com wrote:

From: Dave Martindale dave.martindale@gmail.com
Subject: Re: [time-nuts] White LED's
To: "Discussion of precise time and frequency measurement" time-nuts@febo.com
Date: Saturday, 30 January, 2010, 19:12

Hmm.  Has anyone built a strobe light using LEDs instead of a xenon flash tube?  I can see the appeal of building something that doesn't need high voltage to fire or trigger the tube.  Yes, you probably couldn't get as much light as a big Xenon tube, but there are applications where you don't need to illuminate a large area.  (Recent example of where I wished I had a stroboscope: looking at the balance wheel of a pocket watch).

How high can you push the drive current of a LED if the pulse is short?  Of course you have to keep the average dissipation below what the device is rated for, but there must be a peak current limit too.

    Dave

On 30/01/2010 01:17, Robert Atkinson wrote:

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Hi Dave:

LEDs are used on many cell phone cameras in just that way.  The data
sheets for the LEDs have the pulse use specs.

At:  http://www.sd36.bc.ca/sulhts/departments/elx/p/elec.html
scroll down to the "Boy Scout Motor" and notice a common LED held by two
wires that's being used as a strobe light.

Have Fun,

Brooke Clarke
http://www.PRC68.com

Dave Martindale wrote:

Chuck Harris wrote:

Some white LEDs use phosphors, others use scintillators it varies from
manufacturer to manufacturer and part no to part no.

Bruce

I remember hearing about a law suit in an engineering law class I had to
take way back when.  It seems a farmer had a long fence running under and
parallel to a high tension distribution line.  He had hidden a copper line
in it and was harvesting enough power to operate most of his farm buildings.
This amounted to a measurable loss from the distribution line and the power
company found him out and sued.  The court ruled he had to pay for power
used in the past and stop getting his power that way.  Considering the
source I don't think this is an urban legend.

Regards.

Max.  K 4 O D S.

Email: max@maxsmusicplace.com

Transistor site http://www.funwithtransistors.net
Vacuum tube site: http://www.funwithtubes.net
Music site: http://www.maxsmusicplace.com

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----- Original Message -----
From: "Chuck Harris" cfharris@erols.com
To: "Discussion of precise time and frequency measurement"
time-nuts@febo.com
Sent: Saturday, January 30, 2010 12:21 PM
Subject: Re: [time-nuts] White LED's

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19:35:00

Chuck Harris wrote:

Here's an interesting bit of opposite experience.  When I had a
restaurant, I had a walk-in freezer.  I wanted to know when the
compressor was running so I wired a light socket across the compressor
contactor coil terminals and located it where I could see it from the
dining room where I sat when not busy.

I tried all sorts of light in that thing. Long life, rough duty, pilot
light, none of them could stand the 2-3 times an hour cycling.  Then I
installed a little 7 watt organ pipe CFL.  It lasted over 5 years and
was still going strong when I closed the restaurant.

Now Chuck, don't go getting all chemophobic on us now!

That's embarrassing to read, it's so stupid.  Like some meaningless
worship ceremony to mother Gaia or something.

Geez, there's less than 10 milligrams of merc in a "100 watt" CFL.  That
is a harmless amount, especially considering that elemental mercury is
fairly harmless.

What'll they come up with next, HAZMAT team if you spill some paint thinner?

John

--
John DeArmond
Tellico Plains, Occupied TN
http://www.neon-john.com    <-- email from here
http://www.johndearmond.com <-- Best damned Blog on the net
PGP key: wwwkeys.pgp.net: BCB68D77

NeonJohn wrote:

If the intention is to cleanup the mercury rather than just the glass
and relatively non toxic phosphor then the cleanup procedure is contrary
to the method outlined in:
http://www.p2pays.org/ref/15/14605.htm

If one is paranoid about mercury spills sprinkling the debris with
flowers of sulphur is a good idea especially if one intends to
repeatedly break CFLs in the same location.

Bruce

Oh I am certain that they can measure the losses, especially today.

I disagree that harvesting the fields from a hundred feet away is
theft, though.  Especially if it is on your own property.

The easements on my property give the power companies the right
to come onto the property and maintain the lines, but they say
nothing about giving them the right to immerse my property in
high flux AC fields.  They were written in a less technical era,
but they are still in force.

-Chuck Harris

Max Robinson wrote:

Wait until they find out there is arsenic in LEDs!

cheers, Neville Michie

On 31/01/2010, at 7:50 AM, NeonJohn wrote:

NeonJohn wrote:

Having looked at the circuitry, I can't see any real reason why cycling
would be hard on the usual CFL.  The filaments glow red the entire time
they are on anyway, and the inverter is a simple FET multivibrator.

I think the reason people leave them on longer than the equivalent
incandescent is CFL's take a while to ramp up to full brilliance, and
they reason that at 1/4 the power draw, they are essentially free to
run.

In any case, I know I leave them on longer than I would if they were
instant on... for real, and EPA has noticed that others do the same.

Me?  With my chemistry and nuke background?  Not likely!

I am just making a statement based on my observations of the eco-hysteria
the powers that be seem to exhibit.

That's why I am sharing.

Yes, and no.  When mercury hits the ground, it splatters into hundreds of
miniballs of mercury.  When you walk on them, they further fracture, and
by the time you are done, you have increased the surface area of the mini
drop of mercury greatly... probably thousands of times.  That increases
the mercury vapor emitted into the room.

Is it harmful?  Maybe.  Maybe not.

As the laws are currently written, if you intentionally pour any amount of
gasoline, or paint thinner onto the ground you are committing a crime.

-Chuck Harris

Bruce Griffiths wrote:

I think they might have gotten a little push back from the sheeple
if they suggested sprinkling any kind of chemical on Mom's carpet.

-Chuck Harris

According to the paper that was linked earlier, there are 3 types of
fluorescent bulbs, some have no heater at all and are started with a high
voltage pulse that causes accelerated damage.
Those suffer from the most life reduction when cycled.

Those with the always on heater suffer the least, but are the least
efficient.

Didier

It's NOT "flowers" it "flour" of sulphur...  as in a fine ground powder...
think wheat flour as is used to bake bread.

-John

===============

Frankly, I think today if you breathe, pee, poo, or do ANYTHING at all you
are likely breaking some law, silly or otherwise.

FWIW,
-John

===========

[snip]

of gasoline, or paint thinner onto the ground you are committing a
crime.

It is known (for whatever reason) as flowers of sulphur by gardeners
medical practitioners (althernative and conventional) and others outside
the US.
http://www.websters-online-dictionary.org/fl/flower+of+sulphur.html

http://mysite.du.edu/~jcalvert/phys/sulphur.htm
http://mysite.du.edu/%7Ejcalvert/phys/sulphur.htm

It is a powder produced by sublimation of sulphur.

Bruce

J. Forster wrote:

Among chemists, it's flour of sulpher. Flowers is an (incorrect & archeic)
popular name, like quicksilver.

-John

===========

When did this list become a discussion of Chemistry?

Is there a time list I can join?

Not that I've never been off topic, or never learned something
from an OT discussion, but this brings to mind dead horses and
the beating thereof. I'll bet there is a better list for this
subject, and that it's just full of shared ignorance.

Bill Hawkins

-----Original Message-----
From: J. Forster
Sent: Saturday, January 30, 2010 10:05 PM
To: Bruce Griffiths
Cc: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Conducting Bench Top Material

Among chemists, it's flour of sulpher. Flowers is an (incorrect & archeic)
popular name, like quicksilver.

-John

===========

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The connection is alchemical,
Don

----- Original Message -----
From: "Bruce Griffiths" bruce.griffiths@xtra.co.nz
To: jfor@quik.com; "Discussion of precise time and frequency measurement"
time-nuts@febo.com
Sent: Saturday, January 30, 2010 8:53 PM
Subject: Re: [time-nuts] Conducting Bench Top Material

Max wrote:

Both long wires running parallel to transmission lines and coils
situated under transformers were used "back in the day."  The power
companies' ability to detect small losses (hundreds of watts on a
line carrying megawatts) has always been much better than the average
person would think.  Well-established law (at least in the US) holds
that it is theft of services, although some folks think it should be otherwise.

I knew several people who lit outbuildings with fluorescent tubes
powered from wires strung in the near field of a 50 kW AM radio
station I once worked for.  The closest farmers had to take
precautions putting up wire fences (limiting the continuous length
and grounding at intervals), without which they could give you a nasty RF burn.

Best regards,

Charles

Max Robinson wrote:

It sounds a bit of a myth to me. I've never done the maths, but I doubt you
could get a lot of power from a wire like this. To power most of his farm
machinery would need many kW.

On the very high power lines, they tend to be location very high, in which case
I would have thought the fields should cancel at long distances, as there will
be 3 out of phase currents.

I think for lighting, you might be able to claim you did it to reduce the
E-field at your house, as you were worried by the health effects. Sine you need
to dump the power somewhere, a light bulb seemed the cheapest dummy load. A 100
W light bulb is a lot cheaper than a 100 W resistor!

On a similar note, I heard about someone who powered his greenhouse by using the
small voltage between neutral and earth that will exist. I know there is at
least 30 mA available at my house, as shorting neutral to earth will trip a 30
mA RCD. But I measured the voltage once, and whilst I can't recall what it was,
it was less than 1 Volt.

Dave

Not wishing to push this O/T thread more O/T but coming from England,
and now in New Zealand, we have these sodium streetlights which I
think are a pain in the neck. They have only two narrow spectra of
yellow light and although they produce light it makes it hard, if not
impossible, to make out colours. I wonder if they are being used in
other members countries?

Steve

2010/1/31 Dave Martindale dave.martindale@gmail.com:

--
Steve Rooke - ZL3TUV & G8KVD
A man with one clock knows what time it is;
A man with two clocks is never quite sure.

Hi Steve,They do use them in the USA.The advantages are,1 High efficiency2 Better visibility in rain and fog. As there is only one main colour you do not get diffraction rainbows.3 Kind to astronomers. A simple narrow stop band optical filter allows astronomers to remove the light pollution. In some areas around observatories they are mandated by local planning regulations.
These are considered to outweigh the disadvantage of no colour rendition.
Robert G8RPI.  

--- On Sun, 31/1/10, Steve Rooke sar10538@gmail.com wrote:

From: Steve Rooke sar10538@gmail.com
Subject: Re: [time-nuts] [OT] Ikea Lamp
To: "Discussion of precise time and frequency measurement" time-nuts@febo.com
Date: Sunday, 31 January, 2010, 9:19

Not wishing to push this O/T thread more O/T but coming from England,
and now in New Zealand, we have these sodium streetlights which I
think are a pain in the neck. They have only two narrow spectra of
yellow light and although they produce light it makes it hard, if not
impossible, to make out colours. I wonder if they are being used in
other members countries?

Steve

2010/1/31 Dave Martindale dave.martindale@gmail.com:

--
Steve Rooke - ZL3TUV & G8KVD
A man with one clock knows what time it is;
A man with two clocks is never quite sure.

time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

In France, it is known as "fleur de souffre", which translates litterally to
"flower of sulphur". In French, there is no confusion possible between the
terms flower (fleur) and flour (farine).

Didier

In my 1963 EH Sargent and Company catalog, they list:

Sulfur, USP, Precipitated Powder
Sulfur, NF Sublimed Powder
Sulfur, Sublimed Flowers (Tech)
Sulfur, Lump (Roll)

And something about Seconds, NIST Grade...

-Chuck Harris

Don Latham wrote:

Steve Rooke wrote:

Sweden has them. It's the classical sodium D1 and D2 lines. Kind of neat
that one can calibrate ones spectrometer by the highway. :)

I think white is becoming more popular now.

Cheers,
Magnus

I believe that it is possible to light a fluorescent tube, at least
dimly, by standing on the ground under a power transmission line
operating at more than 100 kV , holding one end of the tube in your
hand, and sticking the other end up in the air.  I have never done
this, exactly, but I have held a fluorescent tube near a ham antenna
and seen it light, and on the web I have seen photos of people doing
it under electric utility lines.

Of course I have seen fluorescent tubes light near Van de Graaff
generators and Tesla coils.  We all have.  However, such machines
generate E-fields much stronger than you'll find near ground level
under an electric utility line.

I do not believe that one could get a fluorescent tube to light by
holding it near ground level under an 11-kV line.  But this is just my
gut feeling.  I could certainly be wrong.  I have not done the
experiment; nor have I done a calculation of the expected field
strength.

The story of a farmer drawing enough power "to operate most of his
farm buildings" from a wire running under and parallel to a HV line
sounds like an urban legend to me.  As does the story of a "guy that
had a big coil of wire in the roof of his shed and... could light a
100W incandescent bulb from the stray fields."  It's hard to draw
significant power from the field surrounding a power line because a
huge reactance must be tuned out.  If it were easy, then power-
transmission companies would be dissipating substantial and
economically intolerable amounts of power in the ground, which has
non-negligible conductivity.

During my summer working in the engineering department of a Bell
System operating company, I personally observed examples of 60-Hz AC
e.m.f. induced longitudinally in telephone cables running for miles
along rural pole lines, directly under 60-Hz power lines.  It was not
unusual to see an induced e.m.f. of the order of 100 V RMS.  A person
could get a painful shock from this voltage.  However, a human is a
pretty high-resistance load.  You could not draw watts of power from
such a source.  The Thevenin equivalent source impedance was too high.

BTW, it is necessary to distinguish induced e.m.f. from a potential
difference between separated points on the surface of the ground due
to resistance in the ground multiplied by conduction current in
the ground.  Conduction current in the ground arises whenever less
than 100% of the current flowing in a single-phase power line, or the
common-mode current in a three-phase line, does not return through the
neutral wire/cable of the line.  In rural areas where most of the
loads are single-phase, and a three-phase line is tapped for single-
phase loads separated by miles or more, it is not unusual to find very
high ground currents.  I remember observing symptoms of high ground
currents also near electric railroad lines.  As electric locomotive
such as the Pennsylvania RR's GG-1 drew single-phase 25-Hz current
from an overhead wire and returned it through the rails; but a
significant fraction of the return current flowed through the ground,
because the rails were connected to driven "ground" rods, presumably
for safety.  Trolley cars on the streets of Baltimore ran on DC, and
did the same thing.  Some of the ground current would find its way via
safety-ground rods through the neutral wires of the 60-Hz electric
utility.  When this DC flowed through the windings of 60-Hz power
transformers, it partially saturated the transformer cores, causing
waveform distortion, so that 60-Hz harmonics were heard in
neighborhood telephones.

The notion of "ground" as one big equipotential surface, an infinite
sink for charge / current, is a mass delusion.  It's a delusion for DC
and low-frequency AC.  For RF, it is so wrong that words fail me.

-John

I hate the yellow lamps in my area because they are only found in certain vicinities. You're driving along at night, maybe searching for something, and suddenly one of the "street lamps" turns red! It's happened to me a few times...

Dave
----- Original Message -----
From: "Robert Atkinson" <robert8rpi@yahoo.co. uk >
To: "Discussion of precise time and frequency measurement" <time-nuts@ febo .com>
Sent: Sunday, January 31, 2010 4:34:23 AM GMT -07:00 US/Canada Mountain
Subject: Re: [time-nuts] [OT] Ikea Lamp

Hi Steve,They do use them in the USA.The advantages are,1 High efficiency2 Better visibility in rain and fog. As there is only one main colour you do not get diffraction rainbows.3 Kind to astronomers. A simple narrow stop band optical filter allows astronomers to remove the light pollution. In some areas around observatories they are mandated by local planning regulations.
These are considered to outweigh the disadvantage of no colour rendition.
Robert G8RPI.

--- On Sun, 31/1/10, Steve Rooke <sar10538@ gmail .com> wrote:

From: Steve Rooke <sar10538@ gmail .com>
Subject: Re: [time-nuts] [OT] Ikea Lamp
To: "Discussion of precise time and frequency measurement" <time-nuts@ febo .com>
Date: Sunday, 31 January, 2010, 9:19

Not wishing to push this O/T thread more O/T but coming from England,
and now in New Zealand , we have these sodium streetlights which I
think are a pain in the neck. They have only two narrow spectra of
yellow light and although they produce light it makes it hard, if not
impossible, to make out colours. I wonder if they are being used in
other members countries?

Steve

2010/1/31 Dave Martindale < dave . martindale @ gmail .com>:

--
Steve Rooke - ZL3TUV & G8KVD
A man with one clock knows what time it is;
A man with two clocks is never quite sure.

time-nuts mailing list -- time-nuts@ febo .com
To unsubscribe , go to https :// www . febo .com/cgi-bin/mailman/ listinfo /time-nuts
and follow the instructions there.

time-nuts mailing list -- time-nuts@ febo .com
To unsubscribe , go to https :// www . febo .com/cgi-bin/mailman/ listinfo /time-nuts
and follow the instructions there.