Silly question, AC power plugs

[George Herold]

Why do US 120 VAC power plugs have holes in the end of the blades?

George H.

[ne...@jecarter.us]

To allow you to put the shackle of a small lock through the blade to
ensure the item can't be plugged in for use?

[Phil Hobbs]

I suspect it's to mate with a small boss on the blades of the socket, to
make it less likely to jiggle loose. The British solved that problem by
the traditional method of "add mass until nothing breaks."

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net

[Ian Field]

"Phil Hobbs" <pcdhSpamM...@electrooptical.net> wrote in message
news:4FB2BA60...@electrooptical.net...

> ne...@jecarter.us wrote:
>>
>> On Tue, 15 May 2012 11:22:21 -0700 (PDT), George Herold
>> <ghe...@teachspin.com> wrote:
>>
>> >
>> > Why do US 120 VAC power plugs have holes in the end of the blades?
>> >
>> >George H.
>>
>> To allow you to put the shackle of a small lock through the blade to
>> ensure the item can't be plugged in for use?
>
> I suspect it's to mate with a small boss on the blades of the socket, to
> make it less likely to jiggle loose. The British solved that problem by
> the traditional method of "add mass until nothing breaks."

I always marvelled at how the Yanks got away with such flimsy plugs when
half the voltage means twice the current for the same load power.

[Jamie]

George Herold wrote:

> Why do US 120 VAC power plugs have holes in the end of the blades?
>
> George H.

Locking dimple.

Jamie

[Phil Hobbs]

Your Victorian ancestors didn't get it either. ;)

[John Fields]

---
A blade made of brass with a width of 1/4", a thickness of 1/16" and a
length of about an inch is hardly flimsy, and serves us well when we
opt to go to 240V and eke out four times the power available from the
mains without changing plugs.

--
JF

[Chiron]

On Tue, 15 May 2012 11:22:21 -0700, George Herold wrote:

> Why do US 120 VAC power plugs have holes in the end of the blades?
>
> George H.

I've been using those suckers for over fifty years, and it never once
occurred to me to wonder about that... shame on me...

[Michael A. Terrell]

George Herold wrote:
>
> Why do US 120 VAC power plugs have holes in the end of the blades?

So the current can flow, of course! ;-)


--
You can't have a sense of humor, if you have no sense.

[George Herold]

On May 15, 4:19 pm, Phil Hobbs
<pcdhSpamMeSensel...@electrooptical.net> wrote:

Is there such a boss in the female end? Now I'm going to have to rip
open a receptacle.

George H.

[George Herold]

On May 15, 10:15 pm, Chiron

I was looking at 'wall warts' with different 'blades' for different
countries. And no one else has holes in their blades.
(like these)
www.phihong.com/assets/pdf/PSC12R.pdf


George H.

[Michael A. Terrell]

George Herold wrote:
>
> Is there such a boss in the female end? Now I'm going to have to rip
> open a receptacle.

There were, in the early ceramic outlets.

[Chiron]

On Wed, 16 May 2012 01:01:49 -0400, Michael A. Terrell wrote:

> George Herold wrote:
>>
>> Why do US 120 VAC power plugs have holes in the end of the blades?
>
>
> So the current can flow, of course! ;-)

Of course! Once you pointed it out, it was obvious. See what you can
figure out, if you know a little science?



--
Don't mind him; politicians always sound like that.

[k...@att.bizzzzzzzzzzzz]

On Wed, 16 May 2012 10:44:03 -0700, Fred Abse <excret...@invalid.invalid>
wrote:

>On Tue, 15 May 2012 16:19:44 -0400, Phil Hobbs wrote:
>
>> The British solved that problem by
>> the traditional method of "add mass until nothing breaks."
>

>Shame they had to go for thick rectangular section pins with contact only
>on two sides. About a third of the surface area wasted. The ones I've come
>into contact (no pun) with seem to get rather hot on full load.
>
>Nasty clumsy things.
>
>The German Schuko system seems to me to be superior.

Over-designed and too expensive. Typical German stuff.

[k...@att.bizzzzzzzzzzzz]

On Wed, 16 May 2012 01:01:49 -0400, "Michael A. Terrell"

<mike.t...@earthlink.net> wrote:

>
>George Herold wrote:
>>
>> Why do US 120 VAC power plugs have holes in the end of the blades?
>
>
> So the current can flow, of course! ;-)

No, silly! The current in a conductor is carried by electrons, not holes!

[Charles]

wrote in message news:iud5r75736lbfqclo...@4ax.com...

That is correct. There might be other reasons.

[IanM]

k...@att.bizzzzzzzzzzzz wrote:
> On Wed, 16 May 2012 10:44:03 -0700, Fred Abse <excret...@invalid.invalid>
> wrote:
>
>> On Tue, 15 May 2012 16:19:44 -0400, Phil Hobbs wrote:
>>
>>> The British solved that problem by
>>> the traditional method of "add mass until nothing breaks."
>> Shame they had to go for thick rectangular section pins with contact only
>> on two sides. About a third of the surface area wasted. The ones I've come
>> into contact (no pun) with seem to get rather hot on full load.

Shouldn't. A good quality properly wired MK brand plug and socket
will run cool carrying 16A if in reasonable condition. Of course it
should never be carrying 16A for long as the plug is fused at 13A. There
are other brands that are satisfactory. Cheap crap that barely meets the
standard or falsely claims to do so is another matter. I would estimate
that half the moulded on plugs one meets are junk.

>>
>> Nasty clumsy things.
>>
>> The German Schuko system seems to me to be superior.
>
> Over-designed and too expensive. Typical German stuff.

Also extremely vulnerable to damage to the exposed earth contacts at the
top and bottom of the socket.

The French system with the earth pin on the socket is preferable.

You may finf this site interesting:
<http://www.fam-oud.nl/~plugsocket/Overview.html>

--
Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
[at]=@, [dash]=- & [dot]=. *Warning* HTML & >32K emails --> NUL:

[fungus]

On Wednesday, May 16, 2012 7:44:03 PM UTC+2, Fred Abse wrote:
>
> Nasty clumsy things.
>
> The German Schuko system seems to me to be superior.
>

...apart from the fact that you can plug them
in either way around (ie. live/neutral swapped)
causing massive sparks when you try to connect
your printer to your PC due to the difference
in ground levels.

Nope. The best plugs I've seen are the UK ones.

Apart from having the best shape they also
have a fuse inside the plug so the fuse
rating matches the device (gasp!) and
everything else in the house doesn't stop
working when something shorts out.

They also thought to put on/off switches
on all the wall sockets - incredibly useful.

[Ian Field]

<k...@att.bizzzzzzzzzzzz> wrote in message
news:ak48r7tontcvi50lc...@4ax.com...

They've always done it that way!!

In WW2 their tanks had to be literally stripped down out in the field if
anything broke.

[k...@att.bizzzzzzzzzzzz]

On Thu, 17 May 2012 15:25:35 +0100, "Ian Field"
<gangprob...@ntlworld.com> wrote:

>
><k...@att.bizzzzzzzzzzzz> wrote in message
>news:ak48r7tontcvi50lc...@4ax.com...
>> On Wed, 16 May 2012 10:44:03 -0700, Fred Abse
>> <excret...@invalid.invalid>
>> wrote:
>>
>>>On Tue, 15 May 2012 16:19:44 -0400, Phil Hobbs wrote:
>>>
>>>> The British solved that problem by
>>>> the traditional method of "add mass until nothing breaks."
>>>
>>>Shame they had to go for thick rectangular section pins with contact only
>>>on two sides. About a third of the surface area wasted. The ones I've come
>>>into contact (no pun) with seem to get rather hot on full load.
>>>
>>>Nasty clumsy things.
>>>
>>>The German Schuko system seems to me to be superior.
>>
>> Over-designed and too expensive. Typical German stuff.
>>
>
>They've always done it that way!!

...and that has always been a poor excuse.

[et...@whidbey.com]

On Tue, 15 May 2012 11:22:21 -0700 (PDT), George Herold
<ghe...@teachspin.com> wrote:

>

The holes are so you can run a little wire through them to connect to
a power source without a receptacle. Just another variation of the
"suicide cord". I'm surprised you didn't know this as the suicide cord
is just basic electronics.
Eric

[Cydrome Leader]

plus they're large and stupid.

[Cydrome Leader]

is this some sort of metric math?

[Chiron]

I always thought that was the alligator clips that were connected to
mains. Great way to incinerate yourself. Makes a lovely display to
impress your friends as you sparkle and flare... but only that one time,
of course...



--
Celebrity voices impersonated.

[Jamie]

Really?

You may want to use spades instead. They have a little nice indent on
them you can use to lock those onto the tong via that hole. This is a
common practice where a device with its own supply is installed in a
cabinet with no receptacle. THis can be done instead of chopping off the
cord to hard wire it or, if the device comes with a all wart, the spades
will lock on.

Guess Edison's brain was working one day.. Who knows, maybe it came
after him?


Jamie

[Les Cargill]

Jamie wrote:
<snip>

>
> Guess Edison's brain was working one day.. Who knows, maybe it came
> after him?
>

If you'd ever had your brain come after you, you would not
care to repeat the experience, let me tell you.

>
> Jamie
>

--
Les Cargill

[John Larkin]

What's even more "shocking" than his math is that he uses the same
plug for 120 and for 240.


--

John Larkin Highland Technology, Inc

jlarkin at highlandtechnology dot com
http://www.highlandtechnology.com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom laser drivers and controllers
Photonics and fiberoptic TTL data links
VME thermocouple, LVDT, synchro acquisition and simulation

[John Larkin]

On Thu, 17 May 2012 04:16:01 -0700 (PDT), fungus <to...@artlum.com>
wrote:

But the US stuff works just fine. And it's cheap and easy to work
with.

[John Larkin]

120 volts isn't that big a deal to touch.

[Jamie]

ha.
yeah, that's funny ;)

Never heard of those that talk to themselves? We have a couple at
work actually sit there, start up a whole conversation with who knows?

And it some times ends up with hand slapping, desk pounding, and some
crazy joke that no one else heard while they are laughing at it.

But the funniest part is when they get caught doing it! :)


Jamie

[Chiron]

On Thu, 17 May 2012 17:18:20 -0700, John Larkin wrote:

> On Thu, 17 May 2012 17:16:58 GMT, Chiron
> <chiron613.no.spam.@no.spam.please.gmail.com> wrote:
>
>>On Thu, 17 May 2012 09:33:33 -0700, etpm wrote:
>>
>>> On Tue, 15 May 2012 11:22:21 -0700 (PDT), George Herold
>>> <ghe...@teachspin.com> wrote:
>>>
>>>
>>>> Why do US 120 VAC power plugs have holes in the end of the blades?
>>>>
>>>>George H.
>>> The holes are so you can run a little wire through them to connect to
>>> a power source without a receptacle. Just another variation of the
>>> "suicide cord". I'm surprised you didn't know this as the suicide cord
>>> is just basic electronics.
>>> Eric
>>
>>I always thought that was the alligator clips that were connected to
>>mains. Great way to incinerate yourself. Makes a lovely display to
>>impress your friends as you sparkle and flare... but only that one time,
>>of course...
>
> 120 volts isn't that big a deal to touch.

Well, yes, I was exaggerating. Even so, grab one clip with each hand and
you could wind up dead if your heart is a bit wonky. Being kind of
careless, I've frequently given myself some highly unpleasant jolts,
which is why I much prefer to play around with low-voltage stuff like
IC's.

If I lived in Europe, I'm sure I'd be dead by now.

--
It looks like it's up to me to save our skins. Get into that garbage
chute,
flyboy!
-- Princess Leia Organa

[Chiron]

On Thu, 17 May 2012 18:11:48 -0500, Les Cargill wrote:

> If you'd ever had your brain come after you, you would not care to
> repeat the experience, let me tell you.

Yeah, I hate when that happens. The Sixties were *good* to me...



--
This will be a memorable month -- no matter how hard you try to forget it.

[k...@att.bizzzzzzzzzzzz]

On Fri, 18 May 2012 00:32:14 GMT, Chiron

<chiron613.no.spam.@no.spam.please.gmail.com> wrote:

>On Thu, 17 May 2012 17:18:20 -0700, John Larkin wrote:
>
>> On Thu, 17 May 2012 17:16:58 GMT, Chiron
>> <chiron613.no.spam.@no.spam.please.gmail.com> wrote:
>>
>>>On Thu, 17 May 2012 09:33:33 -0700, etpm wrote:
>>>
>>>> On Tue, 15 May 2012 11:22:21 -0700 (PDT), George Herold
>>>> <ghe...@teachspin.com> wrote:
>>>>
>>>>
>>>>> Why do US 120 VAC power plugs have holes in the end of the blades?
>>>>>
>>>>>George H.
>>>> The holes are so you can run a little wire through them to connect to
>>>> a power source without a receptacle. Just another variation of the
>>>> "suicide cord". I'm surprised you didn't know this as the suicide cord
>>>> is just basic electronics.
>>>> Eric
>>>
>>>I always thought that was the alligator clips that were connected to
>>>mains. Great way to incinerate yourself. Makes a lovely display to
>>>impress your friends as you sparkle and flare... but only that one time,
>>>of course...
>>
>> 120 volts isn't that big a deal to touch.
>
>Well, yes, I was exaggerating. Even so, grab one clip with each hand and
>you could wind up dead if your heart is a bit wonky.

Only if you're grounded well. Otherwise you're likely to get only a tingle.

>Being kind of
>careless, I've frequently given myself some highly unpleasant jolts,
>which is why I much prefer to play around with low-voltage stuff like
>IC's.

That's what I told my brothers (power engineers) when I was in college. ;-)

>If I lived in Europe, I'm sure I'd be dead by now.

So would any thinking person.

[Les Cargill]

Chiron wrote:
> On Thu, 17 May 2012 18:11:48 -0500, Les Cargill wrote:
>
>> If you'd ever had your brain come after you, you would not care to
>> repeat the experience, let me tell you.
>
> Yeah, I hate when that happens. The Sixties were *good* to me...
>
>
>

Heh. I was really thinking of Peter Sellers as Dr. Strangelove,
and did not consider that aspect of the joke.

--
Les Cargill

[George Herold]

On May 17, 12:33 pm, e...@whidbey.com wrote:
> On Tue, 15 May 2012 11:22:21 -0700 (PDT), George Herold
>

> <gher...@teachspin.com> wrote:
>
> > Why do US 120 VAC power plugs have holes in the end of the blades?
>
> >George H.
>
> The holes are so you can run a little wire through them to connect to
> a power source without a receptacle.  Just another variation of the
> "suicide cord". I'm surprised you didn't know this as the suicide cord
> is just basic electronics.
> Eric

I've got a suicide plug. US AC prongs on one end, bannana plugs on
the other.
Scary!

George H.

[John Larkin]

On Fri, 18 May 2012 00:32:14 GMT, Chiron

I know guys who are afraid to touch a PCB that they know has no more
than +5 volts on the chips.


--

John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators

Custom timing and laser controllers

Photonics and fiberoptic TTL data links

VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators

[tuinkabouter]

Ever heard of a ground fault circuit interrupter (GFCI)or RCD?

Besides that i'm still alive despite the unpleasant 220 jolts without GFCI.

[Michael A. Terrell]

Those electrons can't move, without holes! :)


--
You can't have a sense of humor, if you have no sense.

[Michael A. Terrell]

The early outlets needed them to retain the plug. Any 'lock' small
enough to go through the holes would be easy to break, with your bare
hands. The metal used in the early outlets didn't flex much, unlike the
newer designs. The contacts were redesigned to make better use of the
better metallurgy, as well.

[Michael A. Terrell]

tuinkabouter wrote:
>
> Besides that i'm still alive despite the unpleasant 220 jolts without GFCI.

SO, your line voltage is only 77 volts?

[Michael A. Terrell]

Jamie wrote:
>
> Les Cargill wrote:
>
> > Jamie wrote:
> >>
> >> Guess Edison's brain was working one day.. Who knows, maybe it came
> >> after him?
> >
> > If you'd ever had your brain come after you, you would not
> > care to repeat the experience, let me tell you.
> >

> ha.
> yeah, that's funny ;)
>
> Never heard of those that talk to themselves? We have a couple at
> work actually sit there, start up a whole conversation with who knows?
>
> And it some times ends up with hand slapping, desk pounding, and some
> crazy joke that no one else heard while they are laughing at it.
>
> But the funniest part is when they get caught doing it! :)

They are just thinking about how often you make a fool of yourself,
and they can't help but laugh at you.

[Michael A. Terrell]

My suicide cord has a piggyback plug, so you can take someone with
you. ;-)

(A piggyback plug is a combination plug & receptacle so you can plug
something else in.)

[John Fields]

On Thu, 17 May 2012 16:52:33 +0000 (UTC), Cydrome Leader
<pres...@MUNGEpanix.com> wrote:

---
Well, we're not dealing with feet and inches, so you figure it out:

120V mains, 120 ohm load, 120 watts

240V mains, 120 ohm load, 480 watts

480
----- = 4
120

--
JF

[John Fields]

---
Connect a 120 ohm resistor across 120V mains. How much power will it
dissipate? Call that P1.

Connect a 120 ohm resistor across 240V mains. How much power will it
dissipate? Call that P2.

Divide P2 by P1. What do you get?
---

>is that he uses the same plug for 120 and for 240.

---
You've never done that?

--
JF

[Roger]

On May 17, 11:16 pm, fungus <to...@artlum.com> wrote:
> On Wednesday, May 16, 2012 7:44:03 PM UTC+2, Fred Abse wrote:
>
> > Nasty clumsy things.
>
> > The German Schuko system seems to me to be superior.
>
> ...apart from the fact that you can plug them
> in either way around (ie. live/neutral swapped)
> causing massive sparks when you try to connect
> your printer to your PC due to the difference
> in ground levels.
>
> Nope. The best plugs I've seen are the UK ones.
>
> Apart from having the best shape they also
> have a fuse inside the plug so the fuse
> rating matches the device (gasp!) and
> everything else in the house doesn't stop
> working when something shorts out.
>
> They also thought to put on/off switches
> on all the wall sockets - incredibly useful.

No, the Australian-New Zealand system is the best. The wall sockets
are all switched.

[Michael A. Terrell]

Roger wrote:

>
> fungus wrote:
> >
> > They also thought to put on/off switches
> > on all the wall sockets - incredibly useful.
>
> No, the Australian-New Zealand system is the best. The wall sockets
> are all switched.

Who needs that? Is everything you plug in so low grade that you have
to turn off the outlet between uses? All I see is that it lowers the
reliability of every outlet by adding more parts. Rube Goldberg would
be proud of those outlets.

[Ian Field]

"Michael A. Terrell" <mike.t...@earthlink.net> wrote in message
news:dqGdnfXFl41TAyrS...@earthlink.com...

>
> Roger wrote:
>>
>> fungus wrote:
>> >
>> > They also thought to put on/off switches
>> > on all the wall sockets - incredibly useful.
>>
>> No, the Australian-New Zealand system is the best. The wall sockets
>> are all switched.
>
>
> Who needs that? Is everything you plug in so low grade that you have
> to turn off the outlet between uses? All I see is that it lowers the
> reliability of every outlet by adding more parts. Rube Goldberg would
> be proud of those outlets.

The reliabilityy is pretty good - unlike the previous unswitched round pin
outlets that were a disaster that frequently didn't wait to happen!

[John Larkin]

On Fri, 18 May 2012 09:54:03 -0500, John Fields

Technically, the wrong answer.

>---
>
>>is that he uses the same plug for 120 and for 240.
>
>---
>You've never done that?

NO!

If the plug is good for 10 amps, you can power a 1200 watt load from
120 volts. That same plug can power a 2400 watt load from 240 volts.

2:1 is the available-power ratio that you can "eke out" , not 4:1.

--

John Larkin Highland Technology Inc

www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators

Custom timing and laser controllers

Photonics and fiberoptic TTL data links

[John Larkin]

That's an excellent SI units for RMS potential, "jolts."

--

John Larkin Highland Technology Inc

www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators

Custom timing and laser controllers

Photonics and fiberoptic TTL data links

[Ian Field]

"John Larkin" <jjla...@highNOTlandTHIStechnologyPART.com> wrote in message
news:3tjfr7tcdffq8945g...@4ax.com...

And if he hadn't still been alive, he'd have been: "phutted".

[John Fields]

What, you don't know how to divide???
---

>>---
>>
>>>is that he uses the same plug for 120 and for 240.
>>
>>---
>>You've never done that?
>
>NO!

---
I do it all the time Mr. Gutless!

That is, I have a 0 -> 140V 1.4kVA VARIAC connected to the paralleled
primaries of a 3kVA isolation transformer with the secondaries wired
in series, so I can get 0 -> 560 VRMS out of the transformer.

Its primaries and secondaries are wired to a terminal block with
ring-tongue terminal jumpers on the user side so I can change the
connections to the transformer as required.

In addition, the output of the transformer is fused and connected to
about 18" of zip cord terminated with a polarized two-terminal US
style AC receptacle.

Into that receptacle normally goes about an 8 foot long suicide cord
with copper mini-alligator clips (Mueller 30C) and vinyl boots
(Mueller BU-32-2) on the business end.

Want a picture?
---

>If the plug is good for 10 amps, you can power a 1200 watt load from
>120 volts. That same plug can power a 2400 watt load from 240 volts.
>
>2:1 is the available-power ratio that you can "eke out" , not 4:1.

---
Sorry, Charlie, but you're cheating again by moving the goalposts.

2:1 is what's available with the load resistance variation of 2:1
which _you_ used, but not with the constant load resistance which _I_
used in my example.

For example: if the mains are 240V, the plug is good for 10 amps, and
the load is 2400 watts, then the load's resistance will be 24 ohms.

Plugging that 24 ohms into a 120V source would result in its
dissipating 600 watts, which is 1/4 the power it would have dissipated
were it connected across 240V mains.

--
JF

[John Fields]

On Sat, 19 May 2012 09:52:29 -0700, John Larkin
<jjla...@highNOTlandTHIStechnologyPART.com> wrote:


>That's an excellent SI units for RMS potential, "jolts."

---
Tech manual alert!!!

"An" is singular; "units" is plural.

--
JF

[John Larkin]

On Sat, 19 May 2012 15:08:30 -0500, John Fields

You said this:

>>>>> A blade made of brass with a width of 1/4", a thickness of 1/16" and a
>>>>> length of about an inch is hardly flimsy, and serves us well when we
>>>>> opt to go to 240V and eke out four times the power available from the
>>>>> mains without changing plugs.

which is just wrong.

[John G]

It happens that Ian Field formulated :

The round ones were English and still in use although fazing out till
the 1960s and still in HongKong till the 1990s and maybe still. There
were 2 or 3 sizes which made moving appliances a pain.

Australia has had the current :D plug and switches in various layouts
since the 1930s.
Todays plug boards are generally not switched but have a 10amp breaker
(not RCD) built in so you cannot string them together and take any more
current than the first one allows which of course is also the nominal
limit of the wall socket which is usually on a 16 amp breaker at the
building switch panel

--
John G

[John Fields]

---
Right you are!

Changing just one word, though, would make it right.

Care to guess which one?

--
JF

[k...@att.bizzzzzzzzzzzz]

On Sun, 20 May 2012 07:37:17 -0700, Fred Abse <excret...@invalid.invalid>
wrote:

>On Wed, 16 May 2012 16:48:52 -0400, k...@att.bizzzzzzzzzzzz wrote:
>
>> On Wed, 16 May 2012 10:44:03 -0700, Fred Abse
>> <excret...@invalid.invalid> wrote:

>>
>>>On Tue, 15 May 2012 16:19:44 -0400, Phil Hobbs wrote:
>>>
>>>> The British solved that problem by
>>>> the traditional method of "add mass until nothing breaks."
>>>

>>>Shame they had to go for thick rectangular section pins with contact only
>>>on two sides. About a third of the surface area wasted. The ones I've
>>>come into contact (no pun) with seem to get rather hot on full load.

>>>
>>>Nasty clumsy things.
>>>
>>>The German Schuko system seems to me to be superior.
>>

>> Over-designed and too expensive. Typical German stuff.
>
>I meant superior to the UK system, not necessarily to anywhere else.

The same applies. The US system is less robust than the UK, but it works and
is a lot cheaper. Over-engineered, isn't.

[John Larkin]

On Sun, 20 May 2012 01:30:51 -0500, John Fields

Easy. Change "four" to "two."

[k...@att.bizzzzzzzzzzzz]

On Sun, 20 May 2012 09:18:07 -0700, John Larkin

That still leaves the "without changing plugs" part.

[Cydrome Leader]

correct.

There are correct receptables and plugs for 240 volt use, I use those. Not
sure why anybody would ever not do that.

[Cydrome Leader]

so you're telling me if an outlet is rated and fused to supply say 15 amps
at 120 volts, that if I double the voltage across it's supply it can now
safely handle 30 amps at 240?

What sort of jenky bullshit "instruments" to you make?

[Cydrome Leader]

Michael A. Terrell <mike.t...@earthlink.net> wrote:
>
> Roger wrote:
>>
>> fungus wrote:
>> >
>> > They also thought to put on/off switches
>> > on all the wall sockets - incredibly useful.
>>
>> No, the Australian-New Zealand system is the best. The wall sockets
>> are all switched.
>
>
> Who needs that? Is everything you plug in so low grade that you have
> to turn off the outlet between uses? All I see is that it lowers the
> reliability of every outlet by adding more parts. Rube Goldberg would
> be proud of those outlets.

That plus they're large and stupid.

[Cydrome Leader]

Fred Abse <excret...@invalid.invalid> wrote:

> On Thu, 17 May 2012 04:16:01 -0700, fungus wrote:
>
>> On Wednesday, May 16, 2012 7:44:03 PM UTC+2, Fred Abse wrote:
>>>

>>> Nasty clumsy things.
>>>
>>> The German Schuko system seems to me to be superior.
>>>
>>>

>> ...apart from the fact that you can plug them in either way around (ie.
>> live/neutral swapped) causing massive sparks when you try to connect your
>> printer to your PC due to the difference in ground levels.
>

> Any printer that has a low impedance path to neutral from ground would be illegal
> in just about any jurisdiction.
> The Schuko (Schutzkontakt) system has two safety ground connections at
> right angles to the pins, That's what the side contacts are for. I suspect
> you must have come across a mis-wired plug or socket.
>
> Schutzkontakt = Protection Contact.
>
> Do you honestly think that VDE, T?V, DIN, etc. would have missed such an
> obvious thing?

yeah, the creators of the mini-DIN connector (stupidest connector ever
created) don't really strike me being clever.

[Cydrome Leader]

George Herold <ghe...@teachspin.com> wrote:

> On May 17, 12:33?pm, e...@whidbey.com wrote:
>> On Tue, 15 May 2012 11:22:21 -0700 (PDT), George Herold
>>

>> <gher...@teachspin.com> wrote:
>>
>> > Why do US 120 VAC power plugs have holes in the end of the blades?
>>
>> >George H.
>>

>> The holes are so you can run a little wire through them to connect to

>> a power source without a receptacle. ?Just another variation of the

>> "suicide cord". I'm surprised you didn't know this as the suicide cord

>> is just basic electronics.
>> Eric
>

> I've got a suicide plug. US AC prongs on one end, bannana plugs on
> the other.
> Scary!
>

> George H.

It's one of the most useful cables there is. Mine are made with red cable
so you know what it is from any end.

[Ian Field]

"Cydrome Leader" <pres...@MUNGEpanix.com> wrote in message
news:jpbdhv$ngg$3...@reader1.panix.com...

He's an escaped loony who likes to pretend he's "professional people".

[k...@att.bizzzzzzzzzzzz]

On Sun, 20 May 2012 19:53:39 +0100, "Ian Field"

At least he's not an engineer.

[John Fields]

On Sun, 20 May 2012 09:18:07 -0700, John Larkin

---
Wrong, but understandable since what I meant was "adding one word."

Mea culpa.

Wanna try again?

--
JF

[John Larkin]

On Sun, 20 May 2012 16:49:50 -0500, John Fields

No. What you said was wrong and stupid, applying "Ohm's Law" without
thinking, as amateurs often do.

Weasel it out yourself.

[John Larkin]

Yeah, we can be spared that embarassment.

[John Fields]

On Sun, 20 May 2012 18:35:43 +0000 (UTC), Cydrome Leader

---
Not at all.

What I'm saying is that if you have an outlet which can handle 15 amps
with 240V across it, then a 16 ohm load will dissipate 3600 watts

Connect that same 16 ohm load across the same socket with 120V across
it and the dissipation drops to 900 watts, ergo

3600W
------ = 4
900W

>
>What sort of jenky bullshit "instruments" to you make?

---
"jenky"?

"to you make"

What do you mean?

--
JF

[John Fields]

On Sun, 20 May 2012 19:53:39 +0100, "Ian Field"

---
Interesting...

you have very little technical expertise, and yet you chose to rail
against us who do.

To what end?

--
JF

[John Larkin]

On Sun, 20 May 2012 18:14:44 -0500, John Fields

Wait a second here. YOU GOT IT WRONG. HE IS RIGHT.

So, where is your "technical expertise" ?

[John Larkin]

On Sun, 20 May 2012 17:39:37 -0500, John Fields

But the 15 amp outlet could *handle* 1800 watts at 120 volts, which is
the issue here.

Weasel.

[k...@att.bizzzzzzzzzzzz]

On Sun, 20 May 2012 17:39:37 -0500, John Fields

I'll attempt to interpret what he said into cluckese, "the outlet and the
circuit is only rated for 15A, moron". Now apologize for being a fathead.

[Michael A. Terrell]

Ian Field wrote:
>
> "Michael A. Terrell" <mike.t...@earthlink.net> wrote in message
> news:dqGdnfXFl41TAyrS...@earthlink.com...

> >
> > Roger wrote:
> >>
> >> fungus wrote:
> >> >
> >> > They also thought to put on/off switches
> >> > on all the wall sockets - incredibly useful.
> >>
> >> No, the Australian-New Zealand system is the best. The wall sockets
> >> are all switched.
> >
> >
> > Who needs that? Is everything you plug in so low grade that you have
> > to turn off the outlet between uses? All I see is that it lowers the
> > reliability of every outlet by adding more parts. Rube Goldberg would
> > be proud of those outlets.
>

> The reliabilityy is pretty good - unlike the previous unswitched round pin
> outlets that were a disaster that frequently didn't wait to happen!

Then you went from substandard crap, to over engineered.


--
You can't have a sense of humor, if you have no sense.

[fungus]

On Sunday, May 20, 2012 4:37:20 PM UTC+2, Fred Abse wrote:
> On Thu, 17 May 2012 04:16:01 -0700, fungus wrote:
>
> > ...apart from the fact that you can plug them in either way around (ie.
> > live/neutral swapped) causing massive sparks when you try to connect your
> > printer to your PC due to the difference in ground levels.
>
> Any printer that has a low impedance path to neutral
> from ground would be illegal in just about any jurisdiction.

Yep, and this is precisely what kills them.

When you have two devices with transformers
the difference between what each device
considers "0V" can be huge depending on
which way around you plug them into the
mains.

If you have a cable with many wires in it
(eg. A 25-pin serial/parallel cable) then
when you connect it the pins with the data
lines can connect before the 0V pin. This
will kill the I/O chips if there's enough
difference between logic ground levels.

I've measured differences of 140V on devices
with Euro plugs. The difference usually goes
down near zero if you reverse the mains plug
of one of them.

> Do you honestly think that VDE, T�V, DIN, etc. would have missed such an
> obvious thing?
>

I think they were probably thinking of
white goods when they designed it, not
printer cables.

> They are fused inside the plug because the UK (unlike most of the rest of
> the world) allows, and uses, ring circuits with a single 30 amp breaker for
> the whole ring. Illegal in many places. Ring circuits in the UK were one
> reason that a standardized Euro-plug never happened.
>

Swings and roundabouts.

In Europe you have no idea how much power
can be drawn from any given socket. Plug
in a heater on the "wrong" side of the
room and you can be plunged into darkness
because it was on the same circuit breaker
as the lighting.

[John Fields]

On Sun, 20 May 2012 15:13:30 -0700, John Larkin

---
Oh, my, Johnny's working himself up to a lather because he's missed
the point.

The word is 120V and it should be added before "mains".

Also, hardly wrong or stupid considering that, in the argument, if a
resistor is connected across 120V mains it'll dissipate a certain
power, while if connected across 240V mains the power dissipation will
quadruple.

Is that not correct, Mr Wizard?

--
JF

[John Fields]

---
How is stating that doubling the voltage across a fixed resistance
quadruples its [power dissipation wrong?
---

>
>So, where is your "technical expertise" ?
>

---
Apparently, in almost every post I write.

--
JF

[John Fields]

---
Weasel?

Geez, John, I answered CL's post and clarified my meaning, which was
that a fixed resistance will dissipate 4 times the power if the
voltage across it is doubled, which is the issue I was addressing.

What's weasly about that?

--
JF

[John Larkin]

On Mon, 21 May 2012 06:23:48 -0500, John Fields

The issue under discussion is how much power you can get from an
outlet, "eke out" in your words. You stated that a given plug, with a
rated current, can deliver 4x as much power at 240 than it can at 120.
You specifically said that's so without changing the plug. Wrong.

[John Larkin]

On Mon, 21 May 2012 07:08:47 -0500, John Fields

That's not what you got wrong.

[Ian Field]

"John Fields" <jfi...@austininstruments.com> wrote in message
news:8tbkr717benuk09im...@4ax.com...

Apparent to anyone who doesn't know any better.

[Ian Field]

"Michael A. Terrell" <mike.t...@earthlink.net> wrote in message

news:P6idnexcas3PfyTS...@earthlink.com...

Our substandard crap was better than drilling brass receptacles into the
wooden skirting board and looping the bare mains wires round little glass
beads nailed to the joists in the attic.

[John Fields]

---
If a plug rated for 15A is plugged into 240V mains, then with a 16 ohm
resistor connected across the plug the resistor will dissipate 3600
watts.

Now unplug the plug from the 240V mains and plug it into 120V mains.
The dissipation will fall to 900 watts.

Isn't 3600 watts 4 times greater than 900 watts?

--
JF

[John Fields]

On Mon, 21 May 2012 15:27:11 +0100, "Ian Field"

---
When I post something technical it's usually written to avoid
ambiguities, to present the subject matter in enough detail to be
understood at the level of the querent and, if required, to provide
the mathematical underpinnings of the design.

In addition, I often provide schematics and simulations and, on
occasion, actually build a prototype to prove, without a doubt, that
the design is sound.

You, on the other hand, seem to content yourself by sitting on the
sidelines hurling insults and posting links to off-topic nonsense and
penile references.

Hardly an individual one could take seriously...

--
JF

[Ian Field]

"John Fields" <jfi...@austininstruments.com> wrote in message

news:3imkr7pjl1cr5c5sm...@4ax.com...

Only at tossers who deserve it.

[fungus]

On Monday, May 21, 2012 1:04:09 PM UTC+2, fungus wrote:
> ... The difference usually goes

> down near zero if you reverse the mains plug
> of one of them.
>

Another "big spark" I just remembered
(because I made one) happens when I unplug
my laptop, take it somewhere else and plug
it in again. If I get the plug the 'wrong'
way around I get a big blue flash in the
socket as it makes contact.

I'm guessing it's because of a capacitor
inside the PSU being reconnected differently
or something... Glub only knows what damage
it's doing to the PSU.

[John Larkin]

On Mon, 21 May 2012 10:17:51 -0500, John Fields

The only math I've ever seen you post is permutations of Ohm's Law.
Which is what you got wrong here.


--

John Larkin Highland Technology, Inc

jlarkin at highlandtechnology dot com

http://www.highlandtechnology.com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators

Custom laser drivers and controllers

Photonics and fiberoptic TTL data links

VME thermocouple, LVDT, synchro acquisition and simulation

[John Fields]

---
Only "wrong" because you refuse to accept my point of view as being
valid, even though I iterate it over and over and offer the circuit
and the math to prove it right.

But no matter.

As for math I've posted, you must not have read a lot of my stuff, but
there was a post only a few days ago which showed a non-Ohms law way
to get the product of two input frequencies as an output and, of
course, the post where I proved that latching relays _don't_ have
infinite gain.

--
JF

[John Fields]

On Mon, 21 May 2012 16:42:01 +0100, "Ian Field"

---
And why are you a fit judge to determine who's a tosser and who isn't
and whether they "deserve" to be insulted?

--
JF

[Jamie]

Yeah, a cattle prod normally gets any one to say and do as you please!

jamie

[John Fields]

---
And yet you demur?

--
JF

[k...@att.bizzzzzzzzzzzz]

On Mon, 21 May 2012 09:38:51 -0500, John Fields

Which has *nothing* to do with the issue at hand, but you knew that. You're
just trying move the goal posts to hide your stupidity.

[Jamie]

Ha, really. Your use of "demur" does not impress me nor does it fit in
the context of the statement I made.

Before visiting the "WORD" buffets, you may want to know the
ingredients before ingestation.

Jamie

[John Larkin]

On Mon, 21 May 2012 16:46:28 -0500, John Fields

The one about multiplying two sine waves, where you got the math
wrong? Sure, I remember that one.

[John Larkin]

That's like trying to hide a mountain.

He just keeps showing us how stupid he's determined to be. You have to
kind of admire that sort of dedication.