Silly question, AC power plugs

[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?


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

 

[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.


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

 

[Michael A. Terrell]

George Herold 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!

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.)


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

 

[John Fields]

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

John Fields <jfields@austininstruments.com> wrote:
On Tue, 15 May 2012 21:42:24 +0100, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:


"Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:4FB2BA60.381879AC@electrooptical.net...
news@jecarter.us wrote:

On Tue, 15 May 2012 11:22:21 -0700 (PDT), George Herold
gherold@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.

---
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.

is this some sort of metric math?

---
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]

On Thu, 17 May 2012 17:11:41 -0700, John Larkin
<jlarkin@highlandtechnology.com> wrote:

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

John Fields <jfields@austininstruments.com> wrote:
On Tue, 15 May 2012 21:42:24 +0100, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:


"Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:4FB2BA60.381879AC@electrooptical.net...
news@jecarter.us wrote:

On Tue, 15 May 2012 11:22:21 -0700 (PDT), George Herold
gherold@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.

---
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.

is this some sort of metric math?


What's even more "shocking" than his math

---
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.


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

 

[Ian Field]

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:dqGdnfXFl41TAyrSnZ2dnUVZ_q6dnZ2d@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
<jfields@austininstruments.com> wrote:

On Thu, 17 May 2012 17:11:41 -0700, John Larkin
jlarkin@highlandtechnology.com> wrote:

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

John Fields <jfields@austininstruments.com> wrote:
On Tue, 15 May 2012 21:42:24 +0100, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:


"Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:4FB2BA60.381879AC@electrooptical.net...
news@jecarter.us wrote:

On Tue, 15 May 2012 11:22:21 -0700 (PDT), George Herold
gherold@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.

---
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.

is this some sort of metric math?


What's even more "shocking" than his math

---
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?

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

 

[John Larkin]

On Fri, 18 May 2012 14:21:11 +0200, tuinkabouter
<dachthetniet@net.invalid> wrote:

On 5/18/2012 2:32 AM, Chiron 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
gherold@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.

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

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

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

 

[Ian Field]

"John Larkin" <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in message
news:3tjfr7tcdffq8945gqafe9d4ah3nckj7ju@4ax.com...

On Fri, 18 May 2012 14:21:11 +0200, tuinkabouter
dachthetniet@net.invalid> wrote:

On 5/18/2012 2:32 AM, Chiron 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
gherold@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.

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

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


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

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

 

[John Fields]

On Sat, 19 May 2012 09:49:10 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Fri, 18 May 2012 09:54:03 -0500, John Fields
jfields@austininstruments.com> wrote:

On Thu, 17 May 2012 17:11:41 -0700, John Larkin
jlarkin@highlandtechnology.com> wrote:

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

John Fields <jfields@austininstruments.com> wrote:
On Tue, 15 May 2012 21:42:24 +0100, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:


"Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:4FB2BA60.381879AC@electrooptical.net...
news@jecarter.us wrote:

On Tue, 15 May 2012 11:22:21 -0700 (PDT), George Herold
gherold@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.

---
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.

is this some sort of metric math?


What's even more "shocking" than his math

---
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?

Technically, the wrong answer.

---
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
<jjlarkin@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
<jfields@austininstruments.com> wrote:

On Sat, 19 May 2012 09:49:10 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Fri, 18 May 2012 09:54:03 -0500, John Fields
jfields@austininstruments.com> wrote:

On Thu, 17 May 2012 17:11:41 -0700, John Larkin
jlarkin@highlandtechnology.com> wrote:

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

John Fields <jfields@austininstruments.com> wrote:
On Tue, 15 May 2012 21:42:24 +0100, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:


"Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:4FB2BA60.381879AC@electrooptical.net...
news@jecarter.us wrote:

On Tue, 15 May 2012 11:22:21 -0700 (PDT), George Herold
gherold@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.

---
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.

is this some sort of metric math?


What's even more "shocking" than his math

---
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?

Technically, the wrong answer.

---
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.

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 :

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:dqGdnfXFl41TAyrSnZ2dnUVZ_q6dnZ2d@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!

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 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]

On Sat, 19 May 2012 14:26:57 -0700, John Larkin
<jjSNIPlarkin@highTHISlandtechnology.com> wrote:

On Sat, 19 May 2012 15:08:30 -0500, John Fields
jfields@austininstruments.com> wrote:

On Sat, 19 May 2012 09:49:10 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Fri, 18 May 2012 09:54:03 -0500, John Fields
jfields@austininstruments.com> wrote:

On Thu, 17 May 2012 17:11:41 -0700, John Larkin
jlarkin@highlandtechnology.com> wrote:

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

John Fields <jfields@austininstruments.com> wrote:
On Tue, 15 May 2012 21:42:24 +0100, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:


"Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:4FB2BA60.381879AC@electrooptical.net...
news@jecarter.us wrote:

On Tue, 15 May 2012 11:22:21 -0700 (PDT), George Herold
gherold@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.

---
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.

is this some sort of metric math?


What's even more "shocking" than his math

---
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?

Technically, the wrong answer.

---
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.


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.

---
Right you are!

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

Care to guess which one?

--
JF

 

[Fred Abse]

On Wed, 16 May 2012 05:23:19 -0700, George Herold wrote:

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

Gently insert and withdraw the plug. You should be able to feel it.

--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)

 

[Fred Abse]

On Wed, 16 May 2012 16:48:52 -0400, krw@att.bizzzzzzzzzzzz wrote:

On Wed, 16 May 2012 10:44:03 -0700, Fred Abse
excretatauris@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.

--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)

 

[Fred Abse]

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, TüV, DIN, etc. would have missed such an
obvious thing?

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 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.

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

Until the switch develops lots of contact resistance.

--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)

 

[krw@att.bizzzzzzzzzzzz]

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

On Wed, 16 May 2012 16:48:52 -0400, krw@att.bizzzzzzzzzzzz wrote:

On Wed, 16 May 2012 10:44:03 -0700, Fred Abse
excretatauris@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.