On Mon, 28 Nov 2005 13:42:53 +0000, Andy Hall
wrote:

I had access to a similar stash at about 4 and was given a ball of
string and a screwdriver to wire them up with. I was using a
soldering iron at about 8 or 9 and going on my own to places like
Henry's in London to buy components at about 10. I still have one of
my early Veroboard projects - a timer made using geranium transistors.

You grew your own "geranium transistors" then?

:-)


--

On Mon, 28 Nov 2005 13:11:34 -0000, "David Lee"
wrote:

Matt wrote...
BTW does anyone happen to know what the Sheffield supply voltage was back
in
the 1950s - I remember a van coming down the street and engineers
converting
all our appliances to work on 240V AC but for the life of me I can't
remember what it was before that.

There is a list online somewhere, google ought to turn it up.

You would think so but I've never been able to find anything useful. Google
is really frustrating when you have been used to proper bibliographic search
engines with real Boolean search, word stemming and wildcard facilities.
Alta Vista used to be best for that but apparently the facility is far too
expensive to maintain so all the search engines have now dumbed down to a
price.

Oh it's there (or was) because I've seen it! Be buggered if I can
find it now though - you are probably right about the Altavista bit
though - from who I remember discussing this with I'd guess this info
was online in around 1998/99 - almost "before google"


--

On Mon, 28 Nov 2005 18:07:56 +0000, Matt
wrote:

On Mon, 28 Nov 2005 13:42:53 +0000, Andy Hall
wrote:

I had access to a similar stash at about 4 and was given a ball of
string and a screwdriver to wire them up with. I was using a
soldering iron at about 8 or 9 and going on my own to places like
Henry's in London to buy components at about 10. I still have one of
my early Veroboard projects - a timer made using geranium transistors.

You grew your own "geranium transistors" then?

:-)


Oh definitely. I even made phototransistors. You could do this
with an OC71 (which came encapsulated in black painted glass).
The procedure was to scrape off most of the black paint and then to
carefully scribe a line near the bottom of the case before carefully
breaking it away.
Inside was a bluish-white opaque paste which could be washed away with
alcohol of some kind. After that, the think could be put back together
and worked very well for optical sensing. I used it in a controller
to switch on lights when the sun went down.


--

..andy

Steve Firth wrote:

Sawney Beane wrote:
Steve Firth wrote:

I'm not familiar with GEC bulbs, but I agree with you that
importing from China may be the best way to give the English
consumer access to quality light bulbs.

You'll find them sold with a GE logo in the USA.


GE sold their consumer-products brand to a French company. I have
various GE medium-base bulbs in my box. They say in several
languages, "Imported by GE." They also say they were made in the
United States. So when the French want world-class bulbs, they
depend on American ingenuity, productivity, quality control, etc
etc etc.

My Sylvania bulbs were made in Saint Marys PA and have French
labels. The only foreign bulbs are GE night-light bulbs from the Philippines.

I have fifteen store-brand bulbs. Their origin is not labeled. To
me, that means store buyers found that American bulbs offered the
best value and that American brand names fetch a premium on the
wholesale market.

Victor Roberts wrote...
I find that a potato usually works well.

Really? I've always found their light output disappointing.

They need to be properly salted - to increase their
conductivity :-)

Salt may be a bad idea - certainly acts as a triplet-quencher and kills the
luminescence in quinine!

David

In article ,
Andy Hall writes:
Oh definitely. I even made phototransistors. You could do this
with an OC71 (which came encapsulated in black painted glass).
The procedure was to scrape off most of the black paint and then to
carefully scribe a line near the bottom of the case before carefully
breaking it away.
Inside was a bluish-white opaque paste which could be washed away with
alcohol of some kind. After that, the think could be put back together
and worked very well for optical sensing. I used it in a controller
to switch on lights when the sun went down.

Scraping the paint of an OC71 turned it into an OCP71 (yes
I did that too). However, you didn't need to take it out
of the glass tube or wash off the white heat sink compound;
it was translucent enough to work just as it was.

--
Andrew Gabriel

I'd be grateful if you could - it's one of those little bits of trivia
that's been niggling in the back of my mind for years! I can't even
remember whether the conversion was increasing the voltage or DC to AC.

Sheffield is listed as having had 200VAC (350V 3-phase) and
230VAC (400V 3-phase) supplies. It also had some 2-phase supplies.

--
Andrew Gabriel

Andrew Gabriel wrote:
In article ,
Andy Hall writes:

Oh definitely. I even made phototransistors. You could do this
with an OC71 (which came encapsulated in black painted glass).
The procedure was to scrape off most of the black paint and then to
carefully scribe a line near the bottom of the case before carefully
breaking it away.
Inside was a bluish-white opaque paste which could be washed away with
alcohol of some kind. After that, the think could be put back together
and worked very well for optical sensing. I used it in a controller
to switch on lights when the sun went down.


Scraping the paint of an OC71 turned it into an OCP71 (yes
I did that too). However, you didn't need to take it out
of the glass tube or wash off the white heat sink compound;
it was translucent enough to work just as it was.

IIRC, the earlier ones were fine. Later they did put opaque compound in
that had to be removed. OC45s also worked, at much reduced sensitivity
to the '71..

--
Sue

Andrew Gabriel wrote...
I'd be grateful if you could - it's one of those little bits of trivia
that's been niggling in the back of my mind for years! I can't even
remember whether the conversion was increasing the voltage or DC to AC.

Sheffield is listed as having had 200VAC (350V 3-phase) and
230VAC (400V 3-phase) supplies. It also had some 2-phase supplies.

Thanks for the info - does it say when they abandoned 200V? I was born in
1952 and we left Sheffield in 1964 so I reckon that it can't have been much
later than 1960.

David

On Mon, 28 Nov 2005 19:58:08 +0000, Palindr?me
wrote:

Andrew Gabriel wrote:
In article ,
Andy Hall writes:

Oh definitely. I even made phototransistors. You could do this
with an OC71 (which came encapsulated in black painted glass).
The procedure was to scrape off most of the black paint and then to
carefully scribe a line near the bottom of the case before carefully
breaking it away.
Inside was a bluish-white opaque paste which could be washed away with
alcohol of some kind. After that, the think could be put back together
and worked very well for optical sensing. I used it in a controller
to switch on lights when the sun went down.


Scraping the paint of an OC71 turned it into an OCP71 (yes
I did that too). However, you didn't need to take it out
of the glass tube or wash off the white heat sink compound;
it was translucent enough to work just as it was.

IIRC, the earlier ones were fine. Later they did put opaque compound in
that had to be removed. OC45s also worked, at much reduced sensitivity
to the '71..

I've used a centrifuge to drive the opaque stuff to the bottom of the
de-painted OC71.

--
Frank Erskine

In article . com,
writes:
The British GEC (General Electric Company)
is not connected with the American GE

The British GEC (General Electric Company) ceased to exist
a few years ago (renamed itself Marconi, and then went bust).
The remaining parts, still trading under the name Marconi,
but now owned by the banks who pulled the plug on them, are
just being split up, with Ericsson getting part of it with
the Marconi name, and the remainder taking on a new name
which I've forgotten.

However, GEC's light bulb manufacture (GEC Osram) was
transfered back to the Germans sometime in the 1980's,
having originally been a German company anyway.
I was working for (a different part of) GEC through the
1980's, and when this happened, we stopped being able
to get Osram lamps on staff discount.

--
Andrew Gabriel

Correct, my mistake thats what you get for using memory and not the regs

Gavin
"Andrew Gabriel" wrote in message
.. .
In article ,
"Gavin Parsons" writes:
according to BS7671 you cannot wire a es fitting backwards as the live
does
not have to be wired to the center pin

Your copy of BS7671 would appear to be missing regulation 553-03-04.
However, lampholders conforming to EN 60238 (both contacts only make
connection just as lamp is fully screwed home, and the screw thread
of the lampholder is not connected to either contact) are exempt.

It is also a PAT test failure to find an ES lampholder where the
ES lampholder is connected the wrong way round.

--
Andrew Gabriel

On Mon, 28 Nov 2005 20:03:56 +0000 (UTC), Frank Erskine
wrote:

On Mon, 28 Nov 2005 19:58:08 +0000, Palindr?me
wrote:

Andrew Gabriel wrote:
In article ,
Andy Hall writes:

Oh definitely. I even made phototransistors. You could do this
with an OC71 (which came encapsulated in black painted glass).
The procedure was to scrape off most of the black paint and then to
carefully scribe a line near the bottom of the case before carefully
breaking it away.
Inside was a bluish-white opaque paste which could be washed away with
alcohol of some kind. After that, the think could be put back together
and worked very well for optical sensing. I used it in a controller
to switch on lights when the sun went down.


Scraping the paint of an OC71 turned it into an OCP71 (yes
I did that too). However, you didn't need to take it out
of the glass tube or wash off the white heat sink compound;
it was translucent enough to work just as it was.

IIRC, the earlier ones were fine. Later they did put opaque compound in
that had to be removed. OC45s also worked, at much reduced sensitivity
to the '71..

I've used a centrifuge to drive the opaque stuff to the bottom of the
de-painted OC71.


Now that's just showing off :-)


--

..andy

In article ,
"David Lee" writes:
Andrew Gabriel wrote...
Sheffield is listed as having had 200VAC (350V 3-phase) and
230VAC (400V 3-phase) supplies. It also had some 2-phase supplies.

Thanks for the info - does it say when they abandoned 200V? I was born in
1952 and we left Sheffield in 1964 so I reckon that it can't have been much
later than 1960.

Well, my book predates the voltage standardisation.
I think Reading was done in 1960, and was one of the last
(and strangely enough, it was also one of the last for
conversion to natural gas).

--
Andrew Gabriel

In message , David Lee
writes
No - if James Dyson really was half as good an engineer as he's cracked
up to be then he would have thought of this and it would have been! As
it is, even if you don't get a shock when you empty the dust container,
dust is transferred all over the outside by static repulsion, which is
not a good design feature for a vacuum cleaner!

Maybe he's just got a wicked sense of humour and designed the dust
catcher as a large Lyden jar.

--
Clive Mitchell
http:/www.bigclive.com

Clive Mitchell wrote:

Maybe he's just got a wicked sense of humour and designed the dust
catcher as a large Lyden jar.

Tell me that's a typoie.

On Mon, 28 Nov 2005 13:55:47 -0500, Sawney Beane
wrote:

Steve Firth wrote:

Sawney Beane wrote:
Steve Firth wrote:

I'm not familiar with GEC bulbs, but I agree with you that
importing from China may be the best way to give the English
consumer access to quality light bulbs.

You'll find them sold with a GE logo in the USA.


GE sold their consumer-products brand to a French company.

The sale of the GE consumer products business did not
include GE Lighting (or, by the way, GE Appliance).

--
Vic Roberts
http://www.RobertsResearchInc.com
To reply via e-mail:
replace xxx with vdr in the Reply to: address
or use e-mail address listed at the Web site.

This information is provided for educational purposes only.
It may not be used in any publication or posted on any Web
site without written permission.

"David Lee" wrote in
message ...
Clive Mitchell wrote...
Subsequently my mum foolishly gave me a battery and torch lamp to play
with and it all went wrong from there.

I wonder how I managed to survive! My grandparents had a drawer full of
mains plugs and sockets that they used to give me to play with as a
toddler. That was fine but, sometime between the ages of 5 and 10, I
gleefully discovered a similar stash in my father's workshop but together
with lamps and cable! I had many happy hours making little projects to
impress my mates, such as a warning system with a switch on the roof and
lamp in the workshop. Occasional short-circuits and flashes and bangs
only added to the fun but fortunately for me my early electrical career
was prematurely terminated when my father discovered that an old radio had
miraculously come back to life and found it's plug to be wired between
live and earth! Somehow he didn't see the funny side and certainly didn't
appreciate my research approach to working out which wire should go to
which pin!

BTW does anyone happen to know what the Sheffield supply voltage was back
in the 1950s - I remember a van coming down the street and engineers
converting all our appliances to work on 240V AC but for the life of me I
can't remember what it was before that.

David

Oh, that's interesting. I can see how an appliance such as an electric
stove could be wired to work on either 120 or 240; but how could a toaster,
fan or light bulbs, for that matter, be reworked for a different voltage
especially if the process involved just a few volts? Seems like a
transformer would be needed for each device.

Terry McGowan

On 28 Nov 2005 20:05:11 GMT, (Andrew
Gabriel) wrote:

In article . com,
writes:
The British GEC (General Electric Company)
is not connected with the American GE

The British GEC (General Electric Company) ceased to exist
a few years ago (renamed itself Marconi, and then went bust).
The remaining parts, still trading under the name Marconi,
but now owned by the banks who pulled the plug on them, are
just being split up, with Ericsson getting part of it with
the Marconi name, and the remainder taking on a new name
which I've forgotten.

You forgot the heavy power engineering side that in the early 90's was
sold off to Alsthom (later renamed for some highly obscure reason to
Alstom)






--

In message ,
TKM writes
Oh, that's interesting. I can see how an appliance such as an electric
stove could be wired to work on either 120 or 240; but how could a
toaster, fan or light bulbs, for that matter, be reworked for a
different voltage especially if the process involved just a few volts?
Seems like a transformer would be needed for each device.

Well I seem to remember that my electric whisk went at twice the speed
once they'd written 240V on the side.

--
Betty Pancake.

In message , Chris Bacon
writes
Maybe he's just got a wicked sense of humour and designed the dust
catcher as a large Lyden jar.

Tell me that's a typoie.


Hmm, I guess Leyden might look a bit more correcter.

--
Clive Mitchell
http:/www.bigclive.com

In article ,
"TKM" writes:

Oh, that's interesting. I can see how an appliance such as an electric
stove could be wired to work on either 120 or 240; but how could a toaster,
fan or light bulbs, for that matter, be reworked for a different voltage
especially if the process involved just a few volts? Seems like a
transformer would be needed for each device.

Electricity company did a survey of each house to get a list
of appliances. Then they ordered voltage conversion kits, or
for or items which couldn't be converted, they put an in-line
autotransformer in the flex. Given the range of voltages in
use, many items at that time had voltage taps on them anyway.
I recall an inline transformer on my parents' TV of the time,
and an enormous (3kW) transformer which was fitted inside the
washing machine (both items I saved when the appliances were
eventually chucked out). My dad still has a B&D drill which
had its windings changed and the rating plate over-stamped.
In some cases, they may have simply provided replacement
appliances.

--
Andrew Gabriel

On Mon 28 Nov 2005 07:19:10, Don Klipstein wrote:


Electrocution is so unreliable that "The Electric Chair"
relies on
delivering enough current and/or power to either cook vital
organs or to deprive the "condemned" from breathing long enough
to impair the brainstem from resuming breathing after the shock
ends (if not cooked first). Many times more than one jolt is
delivered to the "condemned" before the "condemned" person is
declared dead.

As unreliable as electrocution is, I would beware that lack of
electrucution from usually-notfatal shocks is or at least can be
similarly unreliable.

Keep in mind that in the USA, body count as a function of
voltage is not
a whole lot lower for 120V than for 440-480V, despite lack of
440-480V in homes. And on USA Navy ships that have both
110-120V and 440-480V, the lower of these two has a higher body
count! I suspect that people get dangerously careless with
voltages that have a low shock fatality rate!!!



Are the earth-trip devices from this company worth having a closer
look?

http://www.ktec.org/k-tec/personal.htm
http://www.ktec.org/k-tec/current.htm

He says

"A Further Note on 5 mA: This 5 mA value is quite a misleading
quantity. ... This law was written for "let go" exposure to
electric shock and not the higher limit of life saving - by
avoiding ventricular fibrillation - the main cause of death by
electric shock. .... A value of no more than 15mA should be
considered. 10 mA - is better and acceptable. 5 mA - better still
- but sometimes difficult to achieve reliably"

is this correct?

On Mon 28 Nov 2005 10:15:55, wrote:
oups.com

Certainly not a case of 'macho bragging'; I would *strongly*
advise against connecting oneself to any mains Voltage. A
previous post implied that mains Voltage *will* kill; this is
not the case, most people will survive it, whether it be 120V or
240V. However, both Voltages can, and sadly sometimes do, put
enough current through the body to result in death. The risk of
death is small, but not negligable, and not one which it is wise
to take


When I was a kid (and very, very stupid) I ran a wire from the live
socket of the mains and into a top of mains-detector screwdriver.
Then I could touch the screwdriver to objects and test for the
quality of electrical earth they provided.

I tried the cold water tap. I tried the water running from that
time.

THEN --- with one hand I turned off the cold water tap, which was fed
direct from the rising water main, and at the same time I touched the
live wire I was holding in the other hand !!!!

This was in the UK so I got the full 240 volts and I don't know how
many millAmps or Amps.

I just couldn't let go. Somehow it ended and I recoevered fairly
quickly. Afterwards I could see burn marks in my fingers where the
live mains wire had been.

+++++

Someone in this thread said 5mA to 1A was the most dangerous. Is my
experience a case of the current being too high to harm?

On Mon 28 Nov 2005 12:42:50, Andrew Gabriel wrote:
k

I have a book with the voltage of all UK towns listed (and much of
the former Empire too). I can look it up this evening if no one
else knows. BTW, Reading was 200VAC 50Hz. My dad still has his old
B&D drill which was converted from 200V to 240V, and the rating
plate over-stamped.

Huh? Are you saying different towns in the UK had different mains
voltages? When did all this end?

In article ,
Matt writes:
On 28 Nov 2005 20:05:11 GMT, (Andrew
Gabriel) wrote:
The British GEC (General Electric Company) ceased to exist
a few years ago (renamed itself Marconi, and then went bust).
The remaining parts, still trading under the name Marconi,
but now owned by the banks who pulled the plug on them, are
just being split up, with Ericsson getting part of it with
the Marconi name, and the remainder taking on a new name
which I've forgotten.

You forgot the heavy power engineering side that in the early 90's was

Eventually, everything was sold off except for the
telecoms/datacoms businesses, which Marconi decided
to specialise in. Some others which I recall being sold:
GEC Electrical Projects (Steel mill process controls, etc),
GEC Gas Turbines (Power Station generators),
GEC Traffic Automation,
GEC Signals,
Reliance, Shorocks,
Lots of Marconi companies,
Paxman Diesels (Very large diesel engines, e.g. the 125MPH trains),
Hotpoint, Creda, Cannon, McMicheal, Expelair, Osram

The timing of this inverse diversity was just perfect to
have all the remaining eggs in the basket which was dropped
in the dot.com crash. The contrast between how Lord Weinstock
ran the company and the disaster after he retired is
truely stunning -- from a couple of billion pound cash
mountain to a multi-billion pound dept in remarkably
few years.

sold off to Alsthom (later renamed for some highly obscure reason to
Alstom)

The name change was because it became French-owned,
and they couldn't work out how to pronounce Alsthom.

--
Andrew Gabriel

In message , JS
writes
Huh? Are you saying different towns in the UK had different mains
voltages? When did all this end?

I'll make a wild guess at 40 years ago.

Apparently Great Western Road in Glasgow had DC on one side and AC on
the other.

Just as well that changed. How annoying would it be to pop over the
road to your pals house and plug your Playstation in.

--
Clive Mitchell
http:/www.bigclive.com

In article ,
JS writes:

Huh? Are you saying different towns in the UK had different mains
voltages? When did all this end?

1960.
The range was mostly from 200V to 250V before that.

The frequency had been standardised at 50Hz by 1932,
as a result of the 1926 Electricity Supply Act which
provided for the creation of the National Grid to
connect all the generating plant together. The Grid
cost £27M to setup, which was paid for in savings
resulting from replacing older inefficient generators
with substation connections to the grid, and the
reduction in total spare generating plant required.
It cost a further £17M to convert those areas which
were not on 50Hz, so they could be attached to the
Grid. The grid has been upgraded twice by superimposing
a Supergrid on top of it in 1940's and 1960's.

--
Andrew Gabriel

Matt typed


You forgot the heavy power engineering side that in the early 90's was
sold off to Alsthom (later renamed for some highly obscure reason to
Alstom)

The Brits couldn't pronounce it correctly, I believe...

--
Helen D. Vecht:
Edgware.

In message , JS
writes
On Mon 28 Nov 2005 10:15:55, wrote:
roups.com

Certainly not a case of 'macho bragging'; I would *strongly*
advise against connecting oneself to any mains Voltage. A
previous post implied that mains Voltage *will* kill; this is
not the case, most people will survive it, whether it be 120V or
240V. However, both Voltages can, and sadly sometimes do, put
enough current through the body to result in death. The risk of
death is small, but not negligable, and not one which it is wise
to take


When I was a kid (and very, very stupid) I ran a wire from the live
socket of the mains and into a top of mains-detector screwdriver.
Then I could touch the screwdriver to objects and test for the
quality of electrical earth they provided.

I tried the cold water tap. I tried the water running from that
time.

THEN --- with one hand I turned off the cold water tap, which was fed
direct from the rising water main, and at the same time I touched the
live wire I was holding in the other hand !!!!

This was in the UK so I got the full 240 volts and I don't know how
many millAmps or Amps.

Not enough for a darwin award, obviously


--
geoff

Clive Mitchell wrote:
In message , Mike Barnes
writes
I find that a potato usually works well.

Really? I've always found their light output disappointing.

Heh. But their conductivity sometimes proves most stimulating!

NT

In message , raden
writes
This was in the UK so I got the full 240 volts and I don't know how
many millAmps or Amps.

Not enough for a darwin award, obviously

Hey, these things happen when you're young.

According to another site linked to this thread you had a rough
resistance of 500 ohms so only about half an amp would have been passed
(OUCH!). The wet hands might have increased that a bit.

My parents were so paranoid about me playing with the mains that they
deliberately made me scared of it. This was most unhelpful in my early
days as an apprentice electrician. Fortunately I've got over it and
made up for the lost shock opportunities.

Closest to electrocution I must have been (knowingly) was when I was
working with Hussmann Refrigeration and was disconnecting a damaged
compressor from a large refrigeration pack which contained eight
compressors. These were Copeland compressors about the size of car
engines and mounted as a group in a steel frame. It was stiflingly hot
in the plant room and I was jammed in across the rest of the compressors
earthed metal cases in my sweaty coveralls. I had isolated what I
thought was the correct compressor and had just tried a ratchet socket
on one of it's phase terminals for size. I lifted the socket off the
terminal and the compressor started up! Given the scenario and the
extreme noise of compressor rooms that would have muted any yells, I
reckon that was a _very_ close shave.

Same company, long, long hours. Dozing off while working night shift on
control tray conversions. Poked my test lamps into a live terminal
while holding the other test lead end. Wide awake in no time.

Same company again. Lots of random shocks while working live, but more
importantly their stupendous hours (day to night to day) and "territory"
introduced me to the concept of falling asleep at the wheel of my van.
I politely made my departure for different work.

Most embarrassing event was while repairing an automatic barrier gate in
a supermarket. The "reconditioned" control box had several plastic
spacers missing that let the mains PCB touch the case. It also had a
missing brass spacer that was supposed to earth the case. After
swapping the unit over I had to close the gate against the shoppers
before I re-powered the unit to avoid a "crash-through" alarm going off.
A queue built up behind it watching me as I turned the gate back on.
Instead of the short processor initialisation delay followed by the gate
opening, nothing happened. I realised I had left the motor connector
off and reached down to pull the unit back out. As soon as it was clear
of the pillar the wire tension pulled the PCB against the case making it
live at 240V. Since I was holding onto a metal rail with my other hand
I was thrown flat on my back in front of a large crowd of onlookers.
Worse still, the controller was jerked out my hand as I flew back and
struck the top of the gate in front of the queue of people with a loud
bang and flash as the internal PCB had all it's tracks vaporised. Hmm.
Bad day.

--
Clive Mitchell
http:/www.bigclive.com

"Dave Plowman (News)" wrote:

In article ,
Sawney Beane wrote:
I'm not familiar with GEC bulbs, but I agree with you that
importing from China may be the best way to give the English
consumer access to quality light bulbs.

Don't think anyone in the UK is complaining about light 'bulb' quality.
Came from you.

I've always been pleased with screw-in household bulbs. Was I
wrong to think a lot of UK contributors did not like them? It
seemed to me that contributors from other European countries liked
screw-in bulbs. Was I wrong?

That led me to conclude that the problem is the quality of screw-in
bulbs in the UK.

The 1975 Westinghouse Large Lamp Specification Guide has a few
bayonet bulbs of 2 to 11 Watts, one of 18, one of 25, and three of
100 Watts. All are special-purpose bulbs. It appears that bayonet
bases are used to prevent inappropriate substitutions.

I think I see why screw bases are preferred in America. My 100W
A19 weighs 28 grams, while my 60W weighs 27.5. Apparently they
weigh about the same because they have to withstand the same forces
in being handled. Thinner glass may suffer less stress as it's
heated. The glass of these bulbs can be very thin because it takes
only a light touch to install and remove them.

The bayonet bulbs I've found in Japanese and American cars require
more force. If the glass were as thin as an A19's, I'd wear
leather gloves to change a taillight bulb. The glass doesn't
break, but I often have a taillight bulb break loose from its base.

If the UK and America used the same mains voltage, lamps from one
place could be plugged in in the other. Then the UN could hold a
referendum to determine which bulb base was perferred. People who
continued to use the other kind would of course be fined.

"David Lee" wrote in
message . uk...
Chris Bacon wrote...
The last really nasty belt I received was a static shock when I
foolishly put my hand in a Dyson vacuum cleaner canister to dislodge the
fluff

How did that happen, then?

Basically works like a van der Graaf generator. Dry dust particles build
up a static charge by tribo-electrification and this gets transfered to
the walls of the container. Static charge is always repelled towards the
outside of a container and because the dust-container is made of
insulating plastic it builds up on the inside surface of the cylinder. As
soon as an eathed paw is inserted a path to earth is provided and you are
on the receiving end of a large and painful spark!

Used to have the same problem with a HEPA filtered Nilfisk vacuum cleaner
that I used to clean up contaminated spillages of dry alumina powder from
an air abrasive machining apparatus (precision "sand-blaster" I used for
preparing semiconductor specimens). The static charge on the vacuum pipe
(and hence me) - of opposite polarity to that on the dust - would build up
until whatever was most insulating in the circuit via me to ground broke
down, whereupon I would get a nasty shock - until I made up an earthing
strap for the vacuum cleaner!

David

So, if the Dyson has a transparent case -- can't tell from the pictures --
then there ought to be a nice light show in a dark room as the dust whirls
around.

Terry McGowan

On Mon, 28 Nov 2005, Andrew Gabriel wrote:

Really? I've always found their light output disappointing.

Large pickled gherkins light up much better ;-)

Seedless grapes cut so the two halves are held together by only a single
thickness of grapeskin, laid out cut-side-up in a µwave oven and zapped
for 6 seconds or so give more dramatic lighting effects.

On Mon, 28 Nov 2005, Steve Firth wrote:

GEC bulbs used to be manufactured at the Ediswan factory in Leicester
(UK) and exported to the USA.

Are you quite sure of that? To Canada, yes, but to the US? I don't think
GEC ever had a significant market presence in the US.

On Mon, 28 Nov 2005, Chris Bacon wrote:

Some of the best stuff in the world is made in the PRC.

Hooboy. Here we go again.

On Mon, 28 Nov 2005, Steve Firth wrote:

I'm not familiar with GEC bulbs

You'll find them sold with a GE logo in the USA.

Again, are you *quite* sure? My recollection is that GE-branded bulbs for
the US market were primarily manufactured in the US.

On Mon, 28 Nov 2005, wrote:

A few years ago most of what was coming out of China, for some reason
they seemed to export mainly plastic toys, was absolute junk; today,
just a few years later they are making some very high quality products;
Apple computers, for example.

I buy and use a *lot* of Apple computers, and have been doing so for a
little over two decades. The build and materials quality of the recent
Chinese-made units is significantly and demonstrably inferior to the units
made before production was moved to China. Correlation? Yes, definitely.
Causation? Maybe.

Of course, they're still making junk as well, like anywhere else.

And lying about it, with rampant counterfeiting of products *and* of
safety approval labels.

I have a GE (American) SON lamp on my desk in front of me at the moment;
it's clearly marked 'Made in Hungary'. The origin of the company is no
indication as to where the product is made.

In this case, that's a very straightforward answer: GE bought Tungsram,
the Hungarian lampmaker, years ago.

DS

TKM wrote...
So, if the Dyson has a transparent case -- can't tell from the pictures --
then there ought to be a nice light show in a dark room as the dust whirls
around.

No - there will be no charge on the dust once it is in the container - it
will all be repelled to the walls as soon as it enters.

David