Pop wrote:
Something's pretty fishy about this post. I spent a lot of time
in Wales and London both, and never came across a bayonet bulb on
anything run from the Mains.

Something's pretty fishy about this post, too!

Daniel J. Stern wrote:
On Fri, 25 Nov 2005, Zak wrote:

Decent ES fittings have two fingers in the bottom, one contacting
center and the other contacting the base from below. After the first
quarter turn out, the base is isolated. The fitting is tall enough to
make touching the base very unlikely. These must have been standard
since at least 30 years.


Wow. Not in North America, where bayonet-base lamps are not used and the
threaded shell is for lamp retention *and* contact. 'Course, we have
half the mains voltage...

The shell on the bulb is the contact in the netherlands as well. The
threads in the fitting are made of plastic: the contact with the shell
is made from below, by a side contact down in the base.

Yes, you can poke your finger in the fitting and touch the contacts,
even both at the same time. But I cannot touch teh metal of the fitting
when the lamp is deep enough in the fitting to make contact, as the
fitting has a shroud from teh end of the threads of about 8 mm (5/16th in).


Thomas

On Fri, 25 Nov 2005 14:54:33 -0000, "Christian McArdle"
wrote:

with ES fittings, several bulbs have had to be removed
using pliers, including at least 2 which left the fitting unfit for future
service and one that has given me an electric shock. This is despite the
fact that over 90% of the total fittings I have used have been BC.

Screw the bulb in then back it off 1/4 to 1/2 a turn.

sponix

On Fri, 25 Nov 2005, Pop wrote:

What? Of COURSE in NA! The only power in a properly plugged in lamp
socket is the small metal in the bottom center of the socket. The
threaded metal is neutral; no harmful voltage there. That's why lamps
have polarized plugs if the mains connects to the bulb.

You are conveniently disregarding the many improperly-plugged-in lamps --
roughly 50 percent of those without polarised plugs, either because they
antedate the introduction of polarised plugs or because their original
polarised plugs have been replaced with plain ones. You are likewise
conveniently disregarding the many sockets that aren't designed or built
as you and I know they ought to be.

"Chris Bacon" wrote in message
...
Lars wrote:
Here in the UK many of the desk lamps I can buy nowadays take a bulb with
an Ediscon Screw fitting. Also many wall lights for outdoor use
(sometimes with a PIR detector) take an ES fitting bulb.

Try and avoid them.


Thanks for your opinion - is there any reasoning behind it?



Until recently all I ever needed for a general purpose light bulb was a
bayonet fitting. Now ES fittings seem to be appearing! Pictures:
http://www.bltdirect.co.uk/base.htm


Is there a particular advantage of the ES fitting over the bayonet
fitting in these sorts of applications?

No, they are not as good as bayonet fittings.

Thanks for your opinion - - is there any reasoning behind it?

"David Lee" wrote in
message . uk...
Zak wrote in message
.. .
David Lee wrote:

One very nasty DISadvantage is that if an ES fitting has been
incorrectly wired then the cap will be live and it is possible to get a
mains shock whilst changing a bulb

Decent ES fittings have two fingers in the bottom, one contacting center
and the other contacting the base from below.

After the first quarter turn out, the base is isolated. The fitting is
tall enough to make touching the base very unlikely.

These must have been standard since at least 30 years.


Maybe in Holland (I assume that's where ...news.tweaknews.nl... means you
are).
However my experience is very different - only Tuesday evening I had to
check some ES lamps in a school hall very much younger than 30 years and
there was about 1/2 inch of cap standing proud of the fittings. Turned
out not to be a problem as it happened, since some clot had turned off the
circuit breaker for the lighting circuit!

It sounds like you were 'checking' the electrics without knowing whether the
circuit was on or off. So who is the 'clot' ?

OG wrote...
It sounds like you were 'checking' the electrics without knowing whether
the circuit was on or off. So who is the 'clot' ?

Reasonably assumed to be a blown bulb and not obvious which circuits were
controlled by which switches - which were multi-way anyway so not obvious
whether on or off. The only way of assuring that the circuit was off would
be to kill the power to the entire building which would not have been
acceptable and way OTT for simply unscrewing a single lightbulb with
appropriate care! Apart from that the reason for restoring the lighting was
so I could see to safely adjust a faulty channel on a dimmer rack with a hot
chassis - so a possibly live edison fitting was not exactly a great hazard
in comparison!

David

In article , Pop
wrote:

Something's pretty fishy about this post.

Quite. You are posting upside down and not trimming. Therefore the context
is unclear.


--
AJL

Christian McArdle explained :
However, with ES fittings, several bulbs have had to be removed
using pliers, including at least 2 which left the fitting unfit for future
service and one that has given me an electric shock.

Usually due to someone over tightening - Screw the lamp in just enough
to provide adequate contact.


--

Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

There is one situation where an ES fitting is clearly superior: Bulbs subject to shocks and vibrations, like in a handheld inspection lamp.

The wobble of the BC fitting added to the shocks and vibrations will reduce the life of the bulb to only a few days, if at all. With ES fitting the bulb is more securely fastened to the lamp and will last much longer.

Antonio

Andy Luckman ...
Pop wrote:

Something's pretty fishy about this post.

Quite. You are posting upside down and not trimming. Therefore the context
is unclear.

Oh my God - please not again!

Run away and play little boy and don't waste bandwidth with irrelevant crap
if you can't stay on-topic! The posting was factually incorrect but it WAS
perfectly clear, although the manner of the posting may not comply with your
own dogmatic Lillipution religious beliefs. Had I been posting that reply
then I doubt that I would have trimmed very much either, since the
referenced material was still relatively short and totally informative.
Your effort in contrast has completely removed any indication of what it is
that you are whining about and hence it is your pointless whinge in which
the context is not just unclear but totally absent!

David (who doesn't give a damn which end of your egg you open!)

OG wrote:
"Chris Bacon" wrote...
Lars wrote:
Here in the UK many of the desk lamps I can buy nowadays take a bulb with
an Ediscon Screw fitting. Also many wall lights for outdoor use
(sometimes with a PIR detector) take an ES fitting bulb.

Try and avoid them.

Thanks for your opinion - is there any reasoning behind it?

Yes.


Until recently all I ever needed for a general purpose light bulb was a
bayonet fitting. Now ES fittings seem to be appearing! Pictures:
http://www.bltdirect.co.uk/base.htm


Is there a particular advantage of the ES fitting over the bayonet
fitting in these sorts of applications?

No, they are not as good as bayonet fittings.

Thanks for your opinion - - is there any reasoning behind it?

Yes.

according to BS7671 you cannot wire a es fitting backwards as the live does
not have to be wired to the center pin

Gavin
"David Hansen" wrote in message
...
On Fri, 25 Nov 2005 11:38:47 +0000 someone who may be Mike Barnes
wrote this:-

There are several significant disadvantages to ES bulbs over BC
(polarity reversal safety

Wossat?

If someone wires the live to the screw part of the fitting then it
is quite easy for people to touch that part, especially if replacing
a bulb.

Of course in many places whether the live is wired to the inner or
outer part of the fitting depends on which way round the plug is
inserted.

While this doesn't kill millions every day, it is undesirable.



--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

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

Lars wrote:

Here in the UK many of the desk lamps I can buy nowadays take a bulb
with an Ediscon Screw fitting. Also many wall lights for outdoor use
(sometimes with a PIR detector) take an ES fitting bulb.

Until recently all I ever needed for a general purpose light bulb was
a bayonet fitting. Now ES fittings seem to be appearing!
Pictures: http://www.bltdirect.co.uk/base.htm


Is there a particular advantage of the ES fitting over the bayonet
fitting in these sorts of applications?

How many "Brits" does it take to screw in a lightbulb??
If you go by the number posts here, 52

:-)

We've been using screw-in (ES) type bulbs over here ever since Edison
invented the damn thing.
No problems.


--
Regards,
Gary

I know not with what weapons World War III will be fought,
but World War IV will be fought with sticks and stones.

Albert Einstein

Gary wrote:
Lars wrote:

Here in the UK many of the desk lamps I can buy nowadays take a bulb
with an Ediscon Screw fitting. Also many wall lights for outdoor use
(sometimes with a PIR detector) take an ES fitting bulb.

Until recently all I ever needed for a general purpose light bulb was
a bayonet fitting. Now ES fittings seem to be appearing!
Pictures: http://www.bltdirect.co.uk/base.htm


Is there a particular advantage of the ES fitting over the bayonet
fitting in these sorts of applications?


How many "Brits" does it take to screw in a lightbulb??
If you go by the number posts here, 52

Sounds uncomfortably crowded. Must be one of these huge light-house ones...


--
Sue

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember asalcedo
saying something like:

There is one situation where an ES fitting is clearly superior: Bulbs
subject to shocks and vibrations, like in a handheld inspection lamp.

The wobble of the BC fitting added to the shocks and vibrations will
reduce the life of the bulb to only a few days, if at all. With ES
fitting the bulb is more securely fastened to the lamp and will last
much longer.

The simple solution to that is to use 'rough service' bulbs. I find they
last for months under general conditions of normal useage.
--

Dave

asalcedo wrote:

Lars Wrote:

Here in the UK many of the desk lamps I can buy nowadays take a bulb
with an Ediscon Screw fitting. Also many wall lights for outdoor use
(sometimes with a PIR detector) take an ES fitting bulb.

Until recently all I ever needed for a general purpose light bulb was
a bayonet fitting. Now ES fittings seem to be appearing!
Pictures: http://www.bltdirect.co.uk/base.htm


Is there a particular advantage of the ES fitting over the bayonet
fitting in these sorts of applications?


There is one situation where an ES fitting is clearly superior: Bulbs
subject to shocks and vibrations, like in a handheld inspection lamp.

The wobble of the BC fitting added to the shocks and vibrations will
reduce the life of the bulb to only a few days, if at all. With ES
fitting the bulb is more securely fastened to the lamp and will last
much longer.

But doesn't the fact that the bulb is so rigidly fixed add to its failure?
I would have thought that the wobble, you describe, would dampen the stress.

Dave

Gary wrote:

Lars wrote:


How many "Brits" does it take to screw in a lightbulb??
If you go by the number posts here, 52

:-)

We've been using screw-in (ES) type bulbs over here ever since Edison
invented the damn thing.
No problems.

Well, the Yanks have dumbed down so many things over the years, perhaps
you Canadians have done the same/caught the bug :-)

I have friends and relatives in Canada, by the way.

Dave

Dave wrote:
Gary wrote:

Lars wrote:



How many "Brits" does it take to screw in a lightbulb??
If you go by the number posts here, 52

:-)

We've been using screw-in (ES) type bulbs over here ever since Edison
invented the damn thing.
No problems.


Well, the Yanks have dumbed down so many things over the years, perhaps
you Canadians have done the same/caught the bug :-)

I have friends and relatives in Canada, by the way.

Dave


Aaaah, your friends and relatives show good taste.

:-)

--
Regards,
Gary

I know not with what weapons World War III will be fought,
but World War IV will be fought with sticks and stones.

Albert Einstein

"Gary" wrote in message
news
Dave wrote:
Gary wrote:

Lars wrote:



How many "Brits" does it take to screw in a lightbulb??
If you go by the number posts here, 52

:-)

We've been using screw-in (ES) type bulbs over here ever since Edison
invented the damn thing.
No problems.


Well, the Yanks have dumbed down so many things over the years, perhaps
you Canadians have done the same/caught the bug :-)

I have friends and relatives in Canada, by the way.

Dave


Aaaah, your friends and relatives show good taste.

:-)

--
Regards,
Gary

I know not with what weapons World War III will be fought,
but World War IV will be fought with sticks and stones.

Albert Einstein

Seems like I also saw bayonet-based lamps used in France. Anyone know if
they are still used there (or in other parts of continental Europe)? If so,
is the base size the same as the U.K. version?

Terry McGowan

Gary wrote:


Aaaah, your friends and relatives show good taste.

I have to agree to some extent, but both are suffering the economic
climate out there. While I am still enjoying early retirement at the age
of 53 (I am now 59)

:-)

Dave

In article ,
"TKM" writes:

Seems like I also saw bayonet-based lamps used in France. Anyone know if

Lamp sales in France are nearer to a 50/50 split ES/BC than
we in the UK are, but still with BC slightly in the lead.

they are still used there (or in other parts of continental Europe)?

I don't claim to know all the rest of continental Europe, but
I believe it's mostly ES (E27).

If so, is the base size the same as the U.K. version?

Yes, B22d.

Note that European (E27) and US (E26) Edison screw fittings are
not quite the same size (the number is the screw diameter in mm).

--
Andrew Gabriel

On Fri, 25 Nov 2005 11:02:19 GMT, Lars
wrote:

Here in the UK many of the desk lamps I can buy nowadays take a bulb
with an Ediscon Screw fitting. Also many wall lights for outdoor use
(sometimes with a PIR detector) take an ES fitting bulb.

Until recently all I ever needed for a general purpose light bulb was
a bayonet fitting. Now ES fittings seem to be appearing!
Pictures: http://www.bltdirect.co.uk/base.htm


Is there a particular advantage of the ES fitting over the bayonet
fitting in these sorts of applications?

I look after dozens of both types of fitting (front of house) in a
theatre with which I'm involved.

I have to say that I've had problems with most of the ES fittings;
failed lamps jamming in the holders, flickering due to loose lamps and
so on. By far the worst are those bakelite (?) holders which merely
have a "spring" contact for the outer connection.

Yes, BC holders do have problems with sticking plungers, but that's
usually because a lamp has been fitted with a "bulb" with too high a
wattage for the fitting, and there are a few rubbish lampholders
(mainly from a fairly well-known Leeds firm!).

Given the choice, I would go for BC. However, with most things like
"track" lamps, there's only ES available :-(

Oddly enough, SES (E14) fittings don't give much trouble at all.
--
Frank Erskine

One advantage is that employees don`t steal them for the
house/garage.As for touching the base whilst removing them,is this
possible with a H.O. shield fitted.As far as I was aware the H.O.
shield has been compulsory for at least thirty five years..
regards,Mark.

In article . com,
writes:
One advantage is that employees don`t steal them for the
house/garage.As for touching the base whilst removing them,is this
possible with a H.O. shield fitted.As far as I was aware the H.O.
shield has been compulsory for at least thirty five years..
regards,Mark.

H.O. skirt was only required on bayonet cap lampholders
in bath/shower rooms. However, this requirement was dropped
from BS7671:2001 with the introduction of bathroom zones
and specified IP ratings for electrical equipment.

--
Andrew Gabriel

Dave wrote:

I have to agree to some extent, but both are suffering the economic
climate out there. While I am still enjoying early retirement at the age
of 53 (I am now 59)

:-)


Dave


The economic situation in Canada is quite good actually. We are a no
deficit society. Employment numbers are quite good. About 7%
unemployment, depending on the area you live in. It could be better I
suppose.
It appears as though you and I belong to the same club, so to speak. I
retired in 1996 at the ripe old age of 52.
In good ol' "this side of the world" English, *life ain't that bad* at
all. :-)

--
Regards,
Gary

I know not with what weapons World War III will be fought,
but World War IV will be fought with sticks and stones.

Albert Einstein

Pop wrote:

240/50 vs 120/60 - they both kill in very nearly the same length
of time. The heart succumbs at about 46V ac.

Both can, and sometimes do, kill, but the vast majority of people who
manage to connect themselves across either survive the experience.
I've had 240V about ten times, and 415 once, and I'm very much still
here. The last 'mishap' I had was about twenty years ago, and was
caused by a horrible Bakelite fitting which I hadn't noticed was
cracked, and which fell apart in my hands. Most of the others were the
result of taking things apart as a small child, and not taking care,
exposing live contacts.

From a safety point of view, using a lower Voltage, but one still high
enough to possibly kill, is no substitute for using good quality
fittings, and taking reasonable care.

Something I have noticed in the US is that many of the fittings in use,
and still available to buy, are of very poor quality, and would never
be allowed here in the UK. The situation here was pretty similar here
maybe 40 years ago, but things have improved a lot since then. There
are a number of things that I don't like about the design NEMA
connectors, I think that both the British and European ones are better,
though none are perfect (try leaving a British plug on the floor and
stepping on the pins with bare feet (ouch!)), but the quality of many
(by no means all) of the NEMA fittings is a bigger issue than the basic
design of the standard. Also, high-quality NEMA plugs seem to be
rather expensive, at least here. A Hubble 240V 6-15P recently cost me
about 12 pounds (~ $20). Given that most things here are about twice
the price that they are in the US, does that mean that they would be
about $10 over there? I bought this to replace the plug supplied with
a 120V-240V autotransformer (to fit the output), which was just about
the worst plug that I have ever seen.

Pop wrote:

240/50 vs 120/60 - they both kill in very nearly the same length
of time. The heart succumbs at about 46V ac.

Both can, and sometimes do, kill, but the vast majority of people who
manage to connect themselves across either survive the experience.
I've had 240V about ten times, and 415 once, and I'm very much still
here. The last 'mishap' I had was about twenty years ago, and was
caused by a horrible Bakelite fitting which I hadn't noticed was
cracked, and which fell apart in my hands. Most of the others were the
result of taking things apart as a small child, and not taking care,
exposing live contacts.

From a safety point of view, using a lower Voltage, but one still high
enough to possibly kill, is no substitute for using good quality
fittings, and taking reasonable care.

Something I have noticed in the US is that many of the fittings in use,
and still available to buy, are of very poor quality, and would never
be allowed here in the UK. The situation here was pretty similar here
maybe 40 years ago, but things have improved a lot since then. There
are a number of things that I don't like about the design NEMA
connectors, I think that both the British and European ones are better,
though none are perfect (try leaving a British plug on the floor and
stepping on the pins with bare feet (ouch!)), but the quality of many
(by no means all) of the NEMA fittings is a bigger issue than the basic
design of the standard. Also, high-quality NEMA plugs seem to be
rather expensive, at least here. A Hubble 240V 6-15P recently cost me
about 12 pounds (~ $20). Given that most things here are about twice
the price that they are in the US, does that mean that they would be
about $10 over there? I bought this to replace the plug supplied with
a 120V-240V autotransformer (to fit the output), which was just about
the worst plug that I have ever seen.

Pop wrote:

240/50 vs 120/60 - they both kill in very nearly the same length
of time. The heart succumbs at about 46V ac.

Both can, and sometimes do, kill, but the vast majority of people who
manage to connect themselves across either survive the experience.
I've had 240V about ten times, and 415 once, and I'm very much still
here. The last 'mishap' I had was about twenty years ago, and was
caused by a horrible Bakelite fitting which I hadn't noticed was
cracked, and which fell apart in my hands. Most of the others were the
result of taking things apart as a small child, and not taking care,
exposing live contacts.

From a safety point of view, using a lower Voltage, but one still high
enough to possibly kill, is no substitute for using good quality
fittings, and taking reasonable care.

Something I have noticed in the US is that many of the fittings in use,
and still available to buy, are of very poor quality, and would never
be allowed here in the UK. The situation here was pretty similar here
maybe 40 years ago, but things have improved a lot since then. There
are a number of things that I don't like about the design NEMA
connectors, I think that both the British and European ones are better,
though none are perfect (try leaving a British plug on the floor and
stepping on the pins with bare feet (ouch!)), but the quality of many
(by no means all) of the NEMA fittings is a bigger issue than the basic
design of the standard. Also, high-quality NEMA plugs seem to be
rather expensive, at least here. A Hubble 240V 6-15P recently cost me
about 12 pounds (~ $20). Given that most things here are about twice
the price that they are in the US, does that mean that they would be
about $10 over there? I bought this to replace the plug supplied with
a 120V-240V autotransformer (to fit the output), which was just about
the worst plug that I have ever seen.

Hi Dave,

"Rough service bulbs", thank you for the tip. I will try them.

Antonio

I understand your point. The fact though is that the wobble is more like a free rotation, like a pendulum, rather than a damper.

My thinking about it goes like this: even if you rest the inspection lamp (bulb) carefully horizontally, just the weight of the bulb will make it swing within the BC fitting. If the bulb was swung on the other side this translates into a meaningful impact.

Let us say that there is no rotational friction in the bayonet, in this case, the tip of the bulb falls (rotates) with close to a 1g aceleration.

When you rest the inspection lamp in normal working conditions you don't drop it, perhaps 0.3g deceleration. Thus a BC bulb can get 1.3 deceleration versus only 0.3g for a ES bulb.

In article ,
asalcedo wrote:
There is one situation where an ES fitting is clearly superior: Bulbs
subject to shocks and vibrations, like in a handheld inspection lamp.

The wobble of the BC fitting added to the shocks and vibrations will
reduce the life of the bulb to only a few days, if at all. With ES
fitting the bulb is more securely fastened to the lamp and will last
much longer.

No mains incandescent lamp will last long if it's likely to be dropped,
etc. Although RS types are better, but give less light. Either use low
voltage or fluorescent.

--
*Geeks shall inherit the earth *

Dave Plowman London SW
To e-mail, change noise into sound.

On 26 Nov 2005 22:58:07 GMT,it is alleged that
(Andrew Gabriel) spake thusly in uk.d-i-y:

In article ,
"TKM" writes:

Seems like I also saw bayonet-based lamps used in France. Anyone know if

Lamp sales in France are nearer to a 50/50 split ES/BC than
we in the UK are, but still with BC slightly in the lead.

they are still used there (or in other parts of continental Europe)?

I don't claim to know all the rest of continental Europe, but
I believe it's mostly ES (E27).

If so, is the base size the same as the U.K. version?

Yes, B22d.

Note that European (E27) and US (E26) Edison screw fittings are
not quite the same size (the number is the screw diameter in mm).

I had heard this before. I am beginning to wonder if some
manufacturers are unaware (or don't care) about this difference and
are producing E26andabit lampholders? This would go to explain what
appears from this thread to be common experience, namely people in the
US and Canada or who have been there (where all lamps would be E26)
don't know of very many lamps jamming in ES fixtures, whereas in
Europe (E27 base lamps) the experience seems to be they jam quite
often.


--
There are three things which I consider excellent advice. First, don't
smoke to excess. Second, don't drink to excess.
Third, don't marry to excess.
- Mark Twain

asalcedo wrote:


I understand your point. The fact though is that the wobble is more
like a free rotation, like a pendulum, rather than a damper.

My thinking about it goes like this: even if you rest the inspection
lamp (bulb) carefully horizontally, just the weight of the bulb will
make it swing within the BC fitting. If the bulb was swung on the other
side this translates into a meaningful impact.

Let us say that there is no rotational friction in the bayonet, in this
case, the tip of the bulb falls (rotates) with close to a 1g
aceleration.

When you rest the inspection lamp in normal working conditions you
don't drop it, perhaps 0.3g deceleration. Thus a BC bulb can get 1.3
deceleration versus only 0.3g for a ES bulb.

Yes, I see your point now. It did briefly cross my mind as I hit the
send button, but the whisky slowed my fingers down, just enough not to
stop me hitting the send button :-)

Dave

Gary wrote:

It appears as though you and I belong to the same club, so to speak. I
retired in 1996 at the ripe old age of 52.

Aint life grand :-)

In good ol' "this side of the world" English, *life ain't that bad* at
all. :-)

My sister on Vancouver Island is a very good seamstress, so I reckon
that she is making up for her husbands ill health. He got gassed in a
paper mill several years ago and hasn't worked since.

I got a bit bored and took up a hobby job. School caretaker for 5 hours
a day, but that is getting a bit boring now. Maybe it is time to go back
to early retirement.

Regards

Dave

G6KHP

Lars wrote:
Here in the UK many of the desk lamps I can buy nowadays take a bulb
with an Ediscon Screw fitting. Also many wall lights for outdoor use
(sometimes with a PIR detector) take an ES fitting bulb.

Until recently all I ever needed for a general purpose light bulb was
a bayonet fitting. Now ES fittings seem to be appearing!
Pictures: http://www.bltdirect.co.uk/base.htm


Is there a particular advantage of the ES fitting over the bayonet
fitting in these sorts of applications?

Do you buy your desk lamps from IKEA? They seem to use mainly ES (E27)
and SES (E14) fittings.

In the UK screw caps are mainly used on discharge lamps, such as SON
(high pressure sodium), metal halide, mercury etc. For some reason SOX
(low pressure sodium) lamps use bayonet caps. I prefer screw caps;
they hold the lamp more securely, important with large or heavy lamps,
such as the early Philips SL ones, and contary to the experience of
others here, I find that they're less likely to stick in the holders.
ES caps here were often used for low-voltage lamps, such as those in
emergency lighting systems in public buildings, and in buses and
trains, but tungsten GLS lamps are seldom used fur thee purposes today.

wrote in message
oups.com...

Lars wrote:
Here in the UK many of the desk lamps I can buy nowadays take a bulb
with an Ediscon Screw fitting. Also many wall lights for outdoor use
(sometimes with a PIR detector) take an ES fitting bulb.

Until recently all I ever needed for a general purpose light bulb was
a bayonet fitting. Now ES fittings seem to be appearing!
Pictures: http://www.bltdirect.co.uk/base.htm


Is there a particular advantage of the ES fitting over the bayonet
fitting in these sorts of applications?

Do you buy your desk lamps from IKEA? They seem to use mainly ES (E27)
and SES (E14) fittings.

In the UK screw caps are mainly used on discharge lamps, such as SON
(high pressure sodium), metal halide, mercury etc. For some reason SOX
(low pressure sodium) lamps use bayonet caps. I prefer screw caps;
they hold the lamp more securely, important with large or heavy lamps,
such as the early Philips SL ones, and contary to the experience of
others here, I find that they're less likely to stick in the holders.
ES caps here were often used for low-voltage lamps, such as those in
emergency lighting systems in public buildings, and in buses and
trains, but tungsten GLS lamps are seldom used fur thee purposes today.

SOX lamps are fundamentally a Philips technology and they have traditionally
used a bayonet cap. I think it is also used to position the lamp in some
fixtures since the lamp light output distribution is assymetric. SON lamps
were first appeared commercially in N.A. and so utilized the usual E39 or
Mogul Screw as did other HID lamps of the time.

Terry McGowan

In message .com,
writes
Both can, and sometimes do, kill, but the vast majority of people who
manage to connect themselves across either survive the experience. I've
had 240V about ten times, and 415 once, and I'm very much still here.
The last 'mishap' I had was about twenty years ago, and was caused by a
horrible Bakelite fitting which I hadn't noticed was cracked, and which
fell apart in my hands. Most of the others were the result of taking
things apart as a small child, and not taking care, exposing live contacts.

Oh dear. Before we start the macho bragging about how we can "take"
240V, bear in mind that the current flow is the real shock hazard and in
many instances we are lucky that there isn't an easy route to earth.
The only way you could get a 415 shock is if by touching two phases at
once. In most instances you'd get a shock sensation as soon as you
contacted one.

A current as low as 1mA (one thousandth of an amp) is enough to feel
distinctly with a single finger contact. 8mA will cause significant
muscle contraction and a shock sensation to extend the length of an arm.
30mA is the point where current flow to the feet causes asphyxiation by
involuntary contraction of the diaphragm. 100mA has a modest risk of
heart fibrillation. 1A is almost certain heart fibrillation generally
resulting in death if your heart can't be restarted within a short space
of time.

If you really feel you can handle mains then try the Tingle-tron project
on my website. I guarantee that at 8mA you'll be squealing like a pig.
That's about a quarter of the current it takes to light a small 8W plug
in night light.

Just to make sure everyone knows. You can pass enough current to earth
to be in serious trouble without an earth leakage breaker tripping. If
you make a contact across live and neutral (hot and return) then the
earth leakage breaker isn't even going to be bothered about how much
current you pass. It'll see you as a normal resistive load.

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

wrote:


In the UK screw caps are mainly used on discharge lamps, such as SON
(high pressure sodium), metal halide, mercury etc. For some reason SOX
(low pressure sodium) lamps use bayonet caps. I prefer screw caps;
they hold the lamp more securely, important with large or heavy lamps,
such as the early Philips SL ones, and contary to the experience of
others here, I find that they're less likely to stick in the holders.

Good point! They are relatively heavy, expensive bulbs, mounted on
poles where there may be movement and vibration. So the mounting
system must be secure. The fixture may get wet on foggy days, so
the system can't be prone to corrosion and sticking. The
maintenance man may be on a metal ladder against a metal pole, so
the system must be safe.

The designers of these bulbs must have found that Edison bases could
work very well. (One problem in America is that two of the most
popular sizes of sodium bulbs use the same size base. It may not be
apparent which size a fixture requires. If the bulb doesn't match
the ballast, it will keep cycling on and off, and nobody may know why.)

A maintenance man probably wouldn't use pliers to unscrew a base
unless he knew for sure the circuit was dead. Skin resistance is
usually pretty good protection against serious injury from household
voltage, but it won't protect you so well if you're gripping metal
pliers. On the few occasions I've unscrewed the bases of broken
bulbs, I've used rags, not pliers, which could cause an arc besides
a shock. A rag distributes the force you apply and reduces the
possibility of glass getting in the eyes.

I'm more mistrustful of bayonet bases than Edison bases. Most
bayonet bulbs I deal with are automobile tail lights, which may have
been corroding and vibrating for decades.

An American can save money by buying unfamiliar foreign brands of
Edison-base bulbs. They may be more troublesome than the familiar
brands. I can buy an American brand with confidence because the big
American companies have lots of experience making Edison-base bulbs
and they are competing for customer loyalty. That's probably true
of bayonet bulbs in England.