How are they supposed to work?

I tagged one of these onto the end of a TLC order just to get an ok
electrician's-sized screwdriver. I don't intend to use the alleged
"testing" facility, but I'm curious how it's supposed to work. It looks
like it's meant to be touched to a live terminal and have the current
flow up the shaft, through a capsule which I assume is the bulb, and
then go via a brass end-cap *into my hand*. The last part of that I'm
not particularly keen on.

I assume that, while they're not well-regarded by most here, neon
screwdrivers don't actually electrocute their owners during intended
use. Is it just that the current flow is very small, and almost all the
voltage is across the neon? Can anyone with a better grasp of electrical
theory explain?

Cheers,

Pete

In message , Pete Verdon
d writes
How are they supposed to work?

I assume that, while they're not well-regarded by most here, neon
screwdrivers don't actually electrocute their owners during intended
use.

well, not if they are OK

else ...

Is it just that the current flow is very small, and almost all the
voltage is across the neon? Can anyone with a better grasp of
electrical theory explain?

Chuck it and spend a tenner on a meter


--
geoff

Pete Verdon wrote:

How are they supposed to work?

You touch the tip on something live or not, and they may light up or not.

I tagged one of these onto the end of a TLC order just to get an ok
electrician's-sized screwdriver. I don't intend to use the alleged
"testing" facility, but I'm curious how it's supposed to work. It looks
like it's meant to be touched to a live terminal and have the current
flow up the shaft, through a capsule which I assume is the bulb, and
then go via a brass end-cap *into my hand*. The last part of that I'm
not particularly keen on.

Yup, is about right - your provide the neutral path.

I assume that, while they're not well-regarded by most here, neon
screwdrivers don't actually electrocute their owners during intended
use.

No, that is usually when they do try to electrocute you. You stick the
driver on a live wire, it neglects to light, so you go ahead and touch
the wire!


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Apr 8, 10:33*pm, John Rumm wrote:
Pete Verdon wrote:
How are they supposed to work?

You touch the tip on something live or not, and they may light up or not.

I tagged one of these onto the end of a TLC order just to get an ok
electrician's-sized screwdriver. I don't intend to use the alleged
"testing" facility, but I'm curious how it's supposed to work. It looks
like it's meant to be touched to a live terminal and have the current
flow up the shaft, through a capsule which I assume is the bulb, and
then go via a brass end-cap *into my hand*. The last part of that I'm
not particularly keen on.

Yup, is about right - your provide the neutral path.

I assume that, while they're not well-regarded by most here, neon
screwdrivers don't actually electrocute their owners during intended
use.

No, that is usually when they do try to electrocute you. You stick the
driver on a live wire, it neglects to light, so you go ahead and touch
the wire!

--
Cheers,

John.

/================================================== ===============\
| * * * * *Internode Ltd - *http://www.internode.co.uk* * * * * *|
|-----------------------------------------------------------------|
| * * * *John Rumm - john(at)internode(dot)co(dot)uk * * * * * * *|
\================================================= ================/

Do they usually have high value resistor inside to limit current to a
few microamps????
Or maybe something less than a milliamp?
e.g. 230 RMS volts/230 k.ohms = 1 milliamp. and 115/230 k.ohms = 0.5
ma.
Peak voltage of 115v about 160 volts more than enough to fire most
neons.

PS. Took a small pocket version half way across the globe and to Malta
and back over Christmas, mixed in woth pens and pencils in brief case;
didn't even realise it was there. Only to have it confiscated on a
short day trip between two Middle Eastern countries! Length of the
blade or something.
Strange thing was that on another flight we were provided with metal
fork and knife, the blade length of which exceeded the confiscated
pocket screwdriver. So thinking of making one that 'looks' like a ball
pint or 0.5mm drafting pencil!
Any suggestions?

terry wrote:

Do they usually have high value resistor inside to limit current to a
few microamps????

yup - you won't even feel a tingle.

PS. Took a small pocket version half way across the globe and to Malta
and back over Christmas, mixed in woth pens and pencils in brief case;
didn't even realise it was there. Only to have it confiscated on a
short day trip between two Middle Eastern countries! Length of the
blade or something.

Was chatting to a friend a while back who had just got back from a
business trip in the middle east. He ended up coming back on a
commercial jet where about 95% of the passengers were returning US
soldiers. A Sargent stood up at the front of the plane, and explained
to them that because (of what he thought were ridiculous) FAA rules,
they now had to pass round a plastic bucket into which they must deposit
any pen knives, screwdrivers or other sharp objects etc. that could
potentially be used as a weapon...

However since they were military personnel, there were allowed to keep
their Ammo, M16s, 9mm side arms, bayonets, and any grenades or claymore
mines they had about their persons!


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 9 Apr, 00:25, Owain wrote:

They are too likely to fail dangerous and hurt somebody, and too likely

Owain

I've read this before - any links to this actually happening? Surely
B&Q wouldn't be selling them for £1.99 if there was anything more than
a very remote possibility of someone electrocuting themselves through
"proper" use of the tool. Failures to the extent that are likely to
harm must be incredibly rare.

Of course, that completely ignores the false negative potential for
them, and that is the real problem with them. Though again they
aren't sold with warning flags all over them. Meters can be just as
dangerous for ignoramuses like me - when I first bought a meter I
would always check the result that I saw with a neon screwdriver as a
few times when I first used the meter I used the wrong settings and
got a false negative, and the screwdriver was useful to help me out
with that.

I'm more confident now that I use the right settings on the meter (its
not that hard to put it on AC 200v really is it???), but I still
keep the screwdriver to hand just in case.

Matt

geoff wrote:
In message , Pete Verdon writes

How are they supposed to work?

Is it just that the current flow is very small, and almost all the
voltage is across the neon? Can anyone with a better grasp of
electrical theory explain?

Chuck it and spend a tenner on a meter

I already have a meter. It's somewhat less effective than the
screwdriver at doing up terminal screws.

(You snipped the bit where I said I bought it as a screwdriver, and
didn't intend to use the neon part.)

Pete

Owain wrote:
Pete Verdon wrote:

Is it just that the current flow is very small, and almost all the
voltage is across the neon? Can anyone with a better grasp of
electrical theory explain?

Basically yes.

Thanks. That's what I was asking.

They are too likely to fail dangerous and hurt somebody, and too likely
to give a false positive or negative, that they are completely unsuited
to the tast and not fit for purpose. A proper electrical tester is much
better.

I went to some length to make clear that that wasn't what I was asking :-)

Pete

Owain wrote:
Pete Verdon wrote:
How are they supposed to work?
I tagged one of these onto the end of a TLC order just to get an ok
electrician's-sized screwdriver. I don't intend to use the alleged
"testing" facility, but I'm curious how it's supposed to work. It
looks like it's meant to be touched to a live terminal and have the
current flow up the shaft, through a capsule which I assume is the
bulb, and then go via a brass end-cap *into my hand*. The last part
of that I'm not particularly keen on.

This is why they are Not Allowed to be used in workplaces.

I assume that, while they're not well-regarded by most here, neon
screwdrivers don't actually electrocute their owners during intended
use.

IF they are working correctly. That's a big if.

Is it just that the current flow is very small, and almost all the
voltage is across the neon? Can anyone with a better grasp of
electrical theory explain?

Basically yes.

They are too likely to fail dangerous and hurt somebody, and too
likely to give a false positive or negative, that they are completely
unsuited to the task and not fit for purpose. A proper electrical
tester is much better.

Always test the tester against a known voltage, then test the unknown
wire, then test the tester again, to be certain you aren't getting a
false reading.

I've followed that advice since you first mentioned it & feel a lot safer,
so thanks for that.

I have a non contact 'voltstick' which is used as you describe. Always
wondered though, why does it light up if waved rapidly from side to side?
No idea how they work.



--
Dave - The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257

On Apr 9, 12:25*am, Owain wrote:
Pete Verdon wrote:
How are they supposed to work?
They are too likely to fail dangerous and hurt somebody, and too likely
to give a false positive or negative, that they are completely unsuited
to the tast and not fit for purpose. A proper electrical tester is much
better.

I've never seen or heard of one that has failed dangerously (at least
not where it's not obvious - snapped in two).

Always test the tester against a known voltage, then test the unknown
wire, then test the tester again, to be certain you aren't getting a
false reading.

But isn't this the same process one should always follow when using an
electrical test screwdriver? So what's the difference? Much easier to
get a false reading from a meter anyway - dodgy leads, low battery,
wrong setting etc.

Jon.

On 9 Apr, 01:33, John Rumm wrote:
Pete Verdon wrote:
How are they supposed to work?

You touch the tip on something live or not, and they may light up or not.

I tagged one of these onto the end of a TLC order just to get an ok
electrician's-sized screwdriver. I don't intend to use the alleged
"testing" facility, but I'm curious how it's supposed to work. It looks
like it's meant to be touched to a live terminal and have the current
flow up the shaft, through a capsule which I assume is the bulb, and
then go via a brass end-cap *into my hand*. The last part of that I'm
not particularly keen on.

Yup, is about right - your provide the neutral path.

I assume that, while they're not well-regarded by most here, neon
screwdrivers don't actually electrocute their owners during intended
use.

No, that is usually when they do try to electrocute you. You stick the
driver on a live wire, it neglects to light, so you go ahead and touch
the wire!

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

The reason they don't light is that the user is ignorant of the why
they light up and is standing on a rubber mat wearing rubber soled
boots. If I've got any doubt I usually find some way of earthing my
other hand to give a definite earth path.

Personally I'd rather use a neon light stick than a meter - leads fall
out of meters, they unhook themselves, batteries fail, you require two
hands and I'm in more danger trying to find somewhere to clip the lead
to earth, and keep it there, than anything else. It's a case of know
your tools, be aware of their limitations and use them properly -
applies to everything from circular saws to screwdrivers.

I've never heard of one failing - has anyone? or is this nanny state
protectionism ? I've been working / playing with electricity since my
Dad gave me an electric train (12vac) when I was 5 and that was over
60 years ago. I've had the odd shock over the years - show me someone
working with electrics regularly who hasn't, but if I'm at all
concerned about a wire, I will just brush my finger across it quickly
to see if it is live.

Rob

In message , Pete Verdon
d writes
How are they supposed to work?

I tagged one of these onto the end of a TLC order just to get an ok
electrician's-sized screwdriver. I don't intend to use the alleged
"testing" facility, but I'm curious how it's supposed to work. It looks
like it's meant to be touched to a live terminal and have the current
flow up the shaft, through a capsule which I assume is the bulb, and
then go via a brass end-cap *into my hand*. The last part of that I'm
not particularly keen on.

I assume that, while they're not well-regarded by most here, neon
screwdrivers don't actually electrocute their owners during intended
use. Is it just that the current flow is very small, and almost all the
voltage is across the neon? Can anyone with a better grasp of
electrical theory explain?

Cheers,

Pete

They do try to electrocute their users if they're the wrong ones. I once
had a 24V version for car use and a 400V (?) for domestic. Guess which
one I used to test a mains wire?
--
Peter

Ying tong iddle-i po!

wrote:
On 9 Apr, 00:25, Owain wrote:
They are too likely to fail dangerous and hurt somebody, and too likely

Owain

I've read this before - any links to this actually happening? Surely
B&Q wouldn't be selling them for £1.99 if there was anything more than
a very remote possibility of someone electrocuting themselves through
"proper" use of the tool. Failures to the extent that are likely to
harm must be incredibly rare.

I have never really considered failure of the tool to be a major issue
(i.e. it conducting more than it should).

Of course, that completely ignores the false negative potential for
them, and that is the real problem with them. Though again they

Yup, I have been bitten by that - once many years ago testing the end of
a live cable to see if I had pulled the right fuse from the CU. Touched
it on the live conductor - no light. Fortunately a little voice
somewhere seemed to doubt - so I shorted live to earth with the tip of
the driver just to make absolutely sure. Flash pop, and the driver
removed itself from the gene pool with a somewhat molten end where the
screwdrivery bit used to be!



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

robgraham wrote:

Personally I'd rather use a neon light stick than a meter - leads fall
out of meters, they unhook themselves, batteries fail, you require two
hands and I'm in more danger trying to find somewhere to clip the lead
to earth, and keep it there, than anything else. It's a case of know
your tools, be aware of their limitations and use them properly -
applies to everything from circular saws to screwdrivers.

I nearly always use some electrical tool or lamp or similar to test if
a circuit is live. Much of the time I will have been using (for
example) my SDS drill so to check if the circuit is off I check that
the drill doesn't run when plugged in to the circuit I'm working on.

As I have nearly always just used the drill I know that it *does*
run when there's electricity there.

The alternative I often use is a mains inspection lamp which I leave
permanently plugged in to the circuit and switched on, a very visible
indication of 'live'! (It's a fluorescent one so, while bulb failure
is possible, it's way less likely than for a filament bulb)

OK, there are times when the above won't work (lighting circuits,
etc.) and you also need to be sure the bit you are working on is the same
circuit as you have the device plugged in but most of the time I still
think my way is better than either neon screwdrivers or meters.

I do have both analogue and digital meters and use them when
appropriate. FWIW for checking 'liveness' an analogue meter has its
advantages over a digital one, it won't indicate due to capacitive
coupling and you don't have to stare at it to check whether it's
indicating 250 volts or 250 millivolts. (On the other hand it will
break if you try and check 250 volts on the 250 millivolt range!)

--
Chris Green

On Tue, 08 Apr 2008 23:11:46 +0100, Pete Verdon
d wrote:

How are they supposed to work?

I tagged one of these onto the end of a TLC order just to get an ok
electrician's-sized screwdriver. I don't intend to use the alleged
"testing" facility, but I'm curious how it's supposed to work. It looks
like it's meant to be touched to a live terminal and have the current
flow up the shaft, through a capsule which I assume is the bulb, and
then go via a brass end-cap *into my hand*. The last part of that I'm
not particularly keen on.

I assume that, while they're not well-regarded by most here, neon
screwdrivers don't actually electrocute their owners during intended
use. Is it just that the current flow is very small, and almost all the
voltage is across the neon? Can anyone with a better grasp of electrical
theory explain?

Cheers,

Pete


The 'driver body contains a neon capsule in series with a large value
resitor.

When a live terminal is touched a voltage is applied across a series
circuit comprising the neon (a high resistance when not conducting),
the resistor , your body and the earth path.

At some point of the mains cycle the neon gas conducts causing a low
resitance path through it and the gas glows.

The current that flows is limited to a very low value by the series
resistance and the rest of the return path. This current is low but
sufficient to keep the neon conducting.

Unless there is fault with the 'driver there isn't any danger to the
user. I've never known of any problems caused by one going faulty.

neon screwdrivers-
holding them in my mouth
whilst doing something else with my hands
is probably a bad idea
cos they can get damp
and i could get poisoned!

[g]

Pete Verdon presented the following explanation :
How are they supposed to work?

I tagged one of these onto the end of a TLC order just to get an ok
electrician's-sized screwdriver. I don't intend to use the alleged "testing"
facility, but I'm curious how it's supposed to work. It looks like it's meant
to be touched to a live terminal and have the current flow up the shaft,
through a capsule which I assume is the bulb, and then go via a brass end-cap
*into my hand*. The last part of that I'm not particularly keen on.

I assume that, while they're not well-regarded by most here, neon
screwdrivers don't actually electrocute their owners during intended use. Is
it just that the current flow is very small, and almost all the voltage is
across the neon? Can anyone with a better grasp of electrical theory explain?

The neon draws a relatively tiny current and to restrict it even more
there is an high value resistor in series with it. The idea is that the
current passes through your body to ground. Problem - you may not
always be at ground potential so it may not light up or lights up
dimly. So one finger on the top and make sure you are touching
something else with a reasonable ground on it.

Problem 2 - if the neon should become damp or faulty internally, you
may be electrocuted.

Problem 3 - They are dim and may not be be seen, which may lead you to
believe something is dead when it is not.

Solution - Don't use it, buy a volt stick which responds to the field
around a live cable and no current needs to flow through you. But test
it before every use.

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

The Medway Handyman formulated on Wednesday :
I have a non contact 'voltstick' which is used as you describe. Always
wondered though, why does it light up if waved rapidly from side to side? No
idea how they work.

They detect the field around the cable. Your waving it about moves it
through a field, which is a good before and after check of the volt
stick.

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

In message , Pete Verdon
d writes
geoff wrote:
In message , Pete Verdon writes

How are they supposed to work?

Is it just that the current flow is very small, and almost all the
voltage is across the neon? Can anyone with a better grasp of
electrical theory explain?

Chuck it and spend a tenner on a meter

I already have a meter. It's somewhat less effective than the
screwdriver at doing up terminal screws.

The corollary is also true


(You snipped the bit where I said I bought it as a screwdriver, and
didn't intend to use the neon part.)

And ?



Pete

--
geoff

wrote in message ...
On 9 Apr,
wrote:

Of course, that completely ignores the false negative potential for
them, and that is the real problem with them.

you should always test the tester before /and/ after use, which will
minimise
false negatives. If you understand how they work, /and/ their limitations
you
can't go far wrong. This applies to all test proceedures.

--
B Thumbs
Change lycos to yahoo to reply

Well said. Did anyone actually answer the original question? The neon tube
is in series with a big resistor, about 1 Megohm if I recall correctly, so
that only a fraction of a milliamp goes through you; this does you no harm
but is quite enough to light up the neon.

newshound wrote:
wrote in message
...
On 9 Apr,
wrote:

Of course, that completely ignores the false negative potential for
them, and that is the real problem with them.

you should always test the tester before /and/ after use, which will
minimise
false negatives. If you understand how they work, /and/ their
limitations you
can't go far wrong. This applies to all test proceedures.

--
B Thumbs
Change lycos to yahoo to reply

Well said. Did anyone actually answer the original question? The neon
tube is in series with a big resistor, about 1 Megohm if I recall
correctly, so that only a fraction of a milliamp goes through you;
this does you no harm but is quite enough to light up the neon.

I think I prefer 'no' electricity goes through you :-)


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257

robgraham wrote:

The reason they don't light is that the user is ignorant of the why
they light up and is standing on a rubber mat wearing rubber soled
boots. If I've got any doubt I usually find some way of earthing my
other hand to give a definite earth path.

That may help a little but you don't really need a conductive path to
earth. The stray capacitance of the body to earth (~150 - 1000 pF) is
enough to complete the circuit.

I've never heard of one failing - has anyone?

There are plenty of recorded cases of shock injuries resulting from neon
screwdrivers. The are potentially dangerous because:

- the series resistor can fail short circuit, particularly the old type
of solid cracked-carbon resistors they used to use in the things;

- in damp conditions the resistor can be bridged by condensation, etc.

- immunity to transient overvoltages (spikes and surges) is poor, and
again the failure mode is to lower the impedance of the device,
increasing body current;

- the neon tube itself can fracture if handled roughly;

- visibility of the live indication is at best poor in outdoor conditions.

OK, the last two points can apply to other voltage indicators, any type
can fail to indicate, but (a) the neon screwdriver is far more likely to
fail than an approved GS38-compliant indicator, and (b) test lamps and
meters tend to fail high-impedance. As has already been said, the
tester should be tested both before and after the test - this is the
basic safe procedure for 'proving dead'.

--
Andy

The Medway Handyman wrote:

correctly, so that only a fraction of a milliamp goes through you;
this does you no harm but is quite enough to light up the neon.

I think I prefer 'no' electricity goes through you :-)

Unless you are going to take up residence in a RF screened cage, that is
probably not an option!

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Harry Bloomfield wrote:

current passes through your body to ground. Problem - you may not always
be at ground potential so it may not light up or lights up dimly. So one
finger on the top and make sure you are touching something else with a
reasonable ground on it.

To be fair, you probably have enough free electrons floating about in
you alone to look like a plenty good enough earth to one of these things.

Problem 2 - if the neon should become damp or faulty internally, you may
be electrocuted.

The contact area of the stud at the top of the driver is probably small
enough to not represent a direct electrocution risk, although you could
get a nasty shock off it.

Problem 3 - They are dim and may not be be seen, which may lead you to
believe something is dead when it is not.

This is probably the most frequent failing...

Solution - Don't use it, buy a volt stick which responds to the field
around a live cable and no current needs to flow through you. But test
it before every use.

Yup, good plan.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"Andy Wade" wrote in message
...
robgraham wrote:

The reason they don't light is that the user is ignorant of the why
they light up and is standing on a rubber mat wearing rubber soled
boots. If I've got any doubt I usually find some way of earthing my
other hand to give a definite earth path.

That may help a little but you don't really need a conductive path to
earth. The stray capacitance of the body to earth (~150 - 1000 pF) is
enough to complete the circuit.

I've never heard of one failing - has anyone?

There are plenty of recorded cases of shock injuries resulting from neon
screwdrivers. The are potentially dangerous because:

where are these cases recorded? I only ask as it is a well known usenet
fault to say such a thing without any evidence to support a case! I have
certainly never heard of one.


--
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)

newshound wrote:
wrote in message ...
On 9 Apr,
wrote:

Of course, that completely ignores the false negative potential for
them, and that is the real problem with them.
you should always test the tester before /and/ after use, which will
minimise
false negatives. If you understand how they work, /and/ their limitations
you
can't go far wrong. This applies to all test proceedures.

--
B Thumbs
Change lycos to yahoo to reply

Well said. Did anyone actually answer the original question? The neon tube
is in series with a big resistor, about 1 Megohm if I recall correctly, so
that only a fraction of a milliamp goes through you; this does you no harm
but is quite enough to light up the neon.


I used to use one about 30 years ago until I received a belt of it, duly
consigned to the bin.
Nowadays I use a pen sized non contact tester for a quick check (always
check it first with a known live)If it gives so much as a single beep
out comes the meter.

Bazza

In message , Peter Twydell
writes
They do try to electrocute their users if they're the wrong ones. I
once had a 24V version for car use and a 400V (?) for domestic. Guess
which one I used to test a mains wire?
Well, some would say that was the user's fault as the 24v one wasn't a
neon but a bulb indicator (neons generally only work above 80-90V unless
there's significant radiation or strong radio signals around) and the
user should have known what tools he was about to use.

--
Clint Sharp

In message
,
robgraham writes
but if I'm at all
concerned about a wire, I will just brush my finger across it quickly
to see if it is live.
Yeah, I knew an electrician who used to do that (notice the past tense)
he realised it was a stupid idea when he discovered that the extra wires
were actually the other two phases for a three phase supply. Still, live
and learn eh? Or not....

Rob

--
Clint Sharp

In message , Clint Sharp
writes
In message , Peter Twydell
writes
They do try to electrocute their users if they're the wrong ones. I
once had a 24V version for car use and a 400V (?) for domestic. Guess
which one I used to test a mains wire?
Well, some would say that was the user's fault as the 24v one wasn't a
neon but a bulb indicator (neons generally only work above 80-90V
unless there's significant radiation or strong radio signals around)
and the user should have known what tools he was about to use.

I was that user. Can't remember exactly what the 24V one was as it's
long been chucked out. It was very similar in appearance to the mains
tester, which was the problem. Just picked it up without checking.

I *have* learned a little bit about safety since then; it was 37 years
ago, after all.
--
Peter

Ying tong iddle-i po!

On Apr 11, 2:51*pm, Peter Twydell wrote:
In message , Clint Sharp
writesIn message , Peter Twydell
writes
They do try to electrocute their users if they're the wrong ones. I
once had a 24V version for car use and a 400V (?) for domestic. Guess
which one I used to test a mains wire?
Well, some would say that was the user's fault as the 24v one wasn't a
neon but a bulb indicator (neons generally only work above 80-90V
unless there's significant radiation or strong radio signals around)
and the user should have known what tools he was about to use.

I was that user. Can't remember exactly what the 24V one was as it's
long been chucked out. It was very similar in appearance to the mains
tester, which was the problem. Just picked it up without checking.

I *have* learned a little bit about safety since then; it was 37 years
ago, after all.
--
Peter

Ying tong iddle-i po!

Hey you are right; I now recall once having a little screwdriver
tester that must have had 12 or 24 volt bulb inside and a lead coming
out top of the handle. Wonder where that is ................... maybe
in one of the vehicles ................... or the garage ..........
the boat .................. hmm!!!!

Back to a neon tester/screwdriver ..............; is not the reason
they will usually light up even if one is NOT standing in bare feet on
a wet floor, due to one's personal body capacitance to something (such
as mother earth!) which is nominally at zero volts? At least seem to
remember testing for 230 volts RMS in the UK doing that?
In North America etc. where nominal RMS to neutral/ground is 115 RMS
not so sure?

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

They detect the field around the cable. Your waving it about moves it
through a field, which is a good before and after check of the volt
stick.

I've been known to light up in a field, too.
--

Dave

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

They detect the field around the cable. Your waving it about moves it
through a field, which is a good before and after check of the volt
stick.

I've been known to light up in a field, too.

With the smoking ban its the only bloody place you can light up...........


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

On Tue, 15 Apr 2008 21:15:27 GMT, "The Medway Handyman"
wrote:



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

They detect the field around the cable. Your waving it about moves it
through a field, which is a good before and after check of the volt
stick.

I've been known to light up in a field, too.

With the smoking ban its the only bloody place you can light up...........

And then you'll probably cause a fire in the crops.

;-)

--
Frank Erskine

Frank Erskine wrote:

And then you'll probably cause a fire in the crops.

Actually the burning of stubble has also been banned for a good number
of years now so it's a no win situation.
:¬)

www.GymRatZ.co.uk wrote:
Frank Erskine wrote:

And then you'll probably cause a fire in the crops.


Actually the burning of stubble has also been banned for a good number
of years now so it's a no win situation.
:¬)
Shaving is far simpler. ;-)

Frank Erskine wrote:
On Tue, 15 Apr 2008 21:15:27 GMT, "The Medway Handyman"
wrote:



Grimly Curmudgeon wrote:

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


They detect the field around the cable. Your waving it about moves it
through a field, which is a good before and after check of the volt
stick.

I've been known to light up in a field, too.

With the smoking ban its the only bloody place you can light up...........


And then you'll probably cause a fire in the crops.

;-)

Not a problem if the crop is tobacco.