Silly question, AC power plugs

[John Fields]

On Thu, 24 May 2012 22:19:26 +0100, "Ian Field"
<gangprobing.alien@ntlworld.com> wrote:

"John Fields" <jfields@austininstruments.com> wrote in message
news:e88tr75itfk5gh6fsn8nj5n5jo6o3jbd9k@4ax.com...
On Thu, 24 May 2012 20:47:08 +0100, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:


"John Fields" <jfields@austininstruments.com> wrote in message
news:313tr7psmf3d5d261ke6otn17bc4klt95b@4ax.com...
On Thu, 24 May 2012 11:27:20 -0700, John Larkin
jlarkin@highlandtechnology.com> wrote:

On Thu, 24 May 2012 05:37:06 -0500, John Fields
jfields@austininstruments.com> wrote:

On Tue, 22 May 2012 22:28:30 -0700, John Larkin
jjSNIPlarkin@highTHISlandtechnology.com> wrote:

On Tue, 22 May 2012 21:24:50 -0400, "krw@att.bizzzzzzzzzzzz"
krw@att.bizzzzzzzzzzzz> wrote:

On Tue, 22 May 2012 14:49:48 -0700, John Larkin
jlarkin@highlandtechnology.com> wrote:

On Tue, 22 May 2012 11:30:05 -0500, John Fields
jfields@austininstruments.com> wrote:

On Tue, 22 May 2012 08:30:21 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:


You have said that you're not an engineer, and that your
electronics
is self-taught. Unless you forced yourself to learn the math, that
puts you at a disadvantage when discussing theory.

One good thing about EE school is that we were forced to learn the
theory and do the math. And we were taught to be careful and check
our
work before turning it in. A lot of engineering is about avoiding
risk, and the more complex a system, the more careful you have to
be
if it's ever going to work. One reason we can build a very complex
laser controller, and get it to work first-rev, is that we check
the
hell out of our stuff before we etch boards. It's a lot of grunt
work,
but it pays off.

---
You never miss a chance to spout platitudes and pat yourself on the
back, do you?

There's nothing glorious about grunt-level checking your work. I can
see why you don't do it.

Because he's incapable of checking anything more complicated than a
555?
...even a 240V plug?

I think he's used to doing simple stuff, like 555s and 4000-series
hairball async logic. If it's just a few chips, you can take some
risks and eventually get it to work most of the time. If you've got an
8-layer board with, say, 500 parts, and simulation isn't feasible, and
you allow a 1% risk of messing any one up, let's see, the chance of it
working is 0.99^500, which is under 1%. It might work on the third or
fourth board spin, maybe.

---
While I've posted a lot more stuff here than you have - pro bono and
without a lot of fanfare -

And usually wrong the first few times.

---
Even if that were true, which it isn't, so what?

The work gets done, if there are any errors they get fixed, and the
querant goes away happy.


.........well, laughing a lot anyway.

---
On his way to the bank.


You charge for the crap you spout here?!

---
If you think it's crap, then clearly you're in the dark.

But, no.

The querents get to determine whether the solutions I propose work, or
not, and then charge whatever the market will bear for their
implementation and/or sale.

I'm only in the loop at the design end and I divulge the secrets for
free.

You, on the other hand, are a talentless hack who aspires to that
forever elusive adequacy.

--
JF

 

[John Fields]

On Thu, 24 May 2012 21:17:16 -0400, "krw@att.bizzzzzzzzzzzz"
<krw@att.bizzzzzzzzzzzz> wrote:

On Thu, 24 May 2012 07:43:03 -0500, John Fields
jfields@austininstruments.com> wrote:

On 24 May 2012 11:16:42 GMT, Jasen Betts <jasen@xnet.co.nz> wrote:

On 2012-05-22, John Fields <jfields@austininstruments.com> wrote:
On Tue, 22 May 2012 08:22:47 -0700, John Larkin
---
Here's what I wrote, with the earlier "120V" omission included:

"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
120V mains without changing plugs."

I thought that it would be obvious to anyone schooled in the art that
under the conditions I outlined the load resistance would remain
constant, but such turned out not to be the case.

The path you took to that conclusion is obvious, but it's obviously wrong.

---
It's not obviously wrong to me, so why don't you show the proof?

A dozen people have but you're impervious to facts.

---
Saying that a dozen people have isn't the same as proving it yourself.

Do you demur because of your inability to provide the proof?
---

---

The load doesn't determine the power available, the supply does that.

---
You must have missed the implied: ..."four times the power available
to the load"...

Which is *wrong*. There is only two times the power AVAILABLE TO THE LOAD.
The current carrying capability of the circuit has not increased.

---
Connect 240V across a 16 ohm load. How much power will the load
dissipate?

Now disconnect the 240V supply and replace it with 120V. How much
power will the load now dissipate?

Notice that since the resistance of the load hasn't changed, the
current into the load has been halved, with the result being that the
power available to the load has been quartered.

--
JF

 

[John Fields]

On Thu, 24 May 2012 21:13:50 -0400, "krw@att.bizzzzzzzzzzzz"
<krw@att.bizzzzzzzzzzzz> wrote:

On Thu, 24 May 2012 15:27:19 -0500, John Fields
jfields@austininstruments.com> wrote:

On Thu, 24 May 2012 10:08:56 -0400, "krw@att.bizzzzzzzzzzzz"
krw@att.bizzzzzzzzzzzz> wrote:

On Thu, 24 May 2012 06:41:54 -0500, John Fields
jfields@austininstruments.com> wrote:

On Wed, 23 May 2012 21:59:27 -0400, "krw@att.bizzzzzzzzzzzz"
krw@att.bizzzzzzzzzzzz> wrote:


Accusing anyone of being racist, without cause, is despicable. He's no better
than Jessie Jackson or Al Sharpton.

---
You don't read for content, do you?

Here's the "dialog" leading up to the accusation:

----------------------------------------------------
KRW: AlwaysWrong comes to mind.

JF: Another favorite target of the lynch mob.

KRW: With good reason.

JF: Sounds like: "We'll give 'em a fair trial and hang 'em in the
morning."

----------
Note that my likening Prongy's relentlessly cruel antagonists to a
lynch mob wasn't questioned by KRW, but rather agreed to with his
"With good reason." comment.

"Relentlessly cruel"? You must be an idiot if you believe that.

---
I'd be an idiot if I _didn't_ believe that since it's as plain as day
that you and the rest of the lynch mob derive great pleasure from
ridiculing him instead of pointing out his errors in a way that would
help, instead of hurt.

Like you (and there are a lot of similarities), AlwaysWrong is immune to the
facts.

---
The point I'm making - and which you keep avoiding - is that you
enjoy being cruel, so why don't you address that issue instead of
skirting it?
---

He is relentless and his presence is cruel.

---
In what way?

Look in a mirror and you'll get a small glimpse.

---
Grade school dodges?

Your true colors are starting to show.
---

---

You've joined him.

---
No, but we're both islands.

Desert.

---
But connected to the mainland through the cloud.
---

---
snipped irrelevance...

Snip yourself

---
What do you mean?

Go away.

---
This isn't as much fun for you as you thought it would be, huh?
---

JF: Don't those white sheets and pointy hats get uncomfortable
sometimes?

KRW: You must be Obama. Anything you don't like is "racist".

----------
Note that the "white sheets and pointy hats" was referring to the
often worn garb of a lynch mob, and since Prongy's race wasn't
mentioned, the race issue wasn't brought up until KRW likened me to
Obama.
----------

Liar. It's *clearly* a reference to the KKK, which you draw the moral
equivalence.

---
The KKK _is_ a lynch mob, so your admission to being a member of a
lynch mob _is_ morally equivalent to being a member of the KKK.

Balloney. The KKK is an obvious (counter) racial slur.

---
Show where race was brought up.
---

As such, you are no better than Sharpton, Jackson, or Obama.
You're despicable.

---
You wallow in self-serving fantasy.
---

Of course you'll squeal that the KKK is much worse than your gang, but
the goal of both is the same; to silence those whom they don't like.

Unfortunately, you won't listen either.

---
What?
---

You are despicable, and no better than Sharpton, Jackson, or
Obama. ...a race baiter.

Your goal post movement isn't going unnoticed.

---
Interesting that you draw attention to what isn't happening, pretend
it is, then damn it and turn a deaf ear to the tune in play.

No, that's your MO.

---
Seems yours is parroting.
---

You're trying to draw attention to your complete lack of
knowledge about simple electricity.

---
"Look at me, I'm a dunce!"???

That makes no sense, but then...

--
JF

 

[Ian Field]

"John Fields" <jfields@austininstruments.com> wrote in message
news:hm0vr718o2nscots4n9r9r2o2i7qvfslpp@4ax.com...

On Thu, 24 May 2012 21:13:50 -0400, "krw@att.bizzzzzzzzzzzz"
krw@att.bizzzzzzzzzzzz> wrote:

On Thu, 24 May 2012 15:27:19 -0500, John Fields
jfields@austininstruments.com> wrote:

On Thu, 24 May 2012 10:08:56 -0400, "krw@att.bizzzzzzzzzzzz"
krw@att.bizzzzzzzzzzzz> wrote:

On Thu, 24 May 2012 06:41:54 -0500, John Fields
jfields@austininstruments.com> wrote:

On Wed, 23 May 2012 21:59:27 -0400, "krw@att.bizzzzzzzzzzzz"
krw@att.bizzzzzzzzzzzz> wrote:


Accusing anyone of being racist, without cause, is despicable. He's
no better
than Jessie Jackson or Al Sharpton.

---
You don't read for content, do you?

Here's the "dialog" leading up to the accusation:

----------------------------------------------------
KRW: AlwaysWrong comes to mind.

JF: Another favorite target of the lynch mob.

KRW: With good reason.

JF: Sounds like: "We'll give 'em a fair trial and hang 'em in the
morning."

----------
Note that my likening Prongy's relentlessly cruel antagonists to a
lynch mob wasn't questioned by KRW, but rather agreed to with his
"With good reason." comment.

"Relentlessly cruel"? You must be an idiot if you believe that.

---
I'd be an idiot if I _didn't_ believe that since it's as plain as day
that you and the rest of the lynch mob derive great pleasure from
ridiculing him instead of pointing out his errors in a way that would
help, instead of hurt.

Like you (and there are a lot of similarities), AlwaysWrong is immune to
the
facts.

---
The point I'm making - and which you keep avoiding - is that you
enjoy being cruel,

If you can't stand the heat, stay out of the kitchen.

 

[Ian Field]

"John Fields" <jfields@austininstruments.com> wrote in message
news:4s3tr71g01esdigog4jamk9g0i94gqiedc@4ax.com...

On Thu, 24 May 2012 10:08:56 -0400, "krw@att.bizzzzzzzzzzzz"
krw@att.bizzzzzzzzzzzz> wrote:

On Thu, 24 May 2012 06:41:54 -0500, John Fields
jfields@austininstruments.com> wrote:

On Wed, 23 May 2012 21:59:27 -0400, "krw@att.bizzzzzzzzzzzz"
krw@att.bizzzzzzzzzzzz> wrote:


Accusing anyone of being racist, without cause, is despicable. He's no
better
than Jessie Jackson or Al Sharpton.

---
You don't read for content, do you?

Here's the "dialog" leading up to the accusation:

----------------------------------------------------
KRW: AlwaysWrong comes to mind.

JF: Another favorite target of the lynch mob.

KRW: With good reason.

JF: Sounds like: "We'll give 'em a fair trial and hang 'em in the
morning."

----------
Note that my likening Prongy's relentlessly cruel antagonists to a
lynch mob wasn't questioned by KRW, but rather agreed to with his
"With good reason." comment.

"Relentlessly cruel"? You must be an idiot if you believe that.

---
I'd be an idiot if I _didn't_ believe that since it's as plain as day
that you and the rest of the lynch mob

"lynch mob"?! - more like a general concensus that you're a fraud.

 

[John Larkin]

On Thu, 24 May 2012 21:22:45 -0400, "krw@att.bizzzzzzzzzzzz"
<krw@att.bizzzzzzzzzzzz> wrote:

On Thu, 24 May 2012 08:19:14 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Thu, 24 May 2012 10:51:52 -0400, "krw@att.bizzzzzzzzzzzz"
krw@att.bizzzzzzzzzzzz> wrote:

On Wed, 23 May 2012 22:35:32 -0700, John Larkin
jjSNIPlarkin@highTHISlandtechnology.com> wrote:

On Wed, 23 May 2012 21:35:32 -0400, "krw@att.bizzzzzzzzzzzz"
krw@att.bizzzzzzzzzzzz> wrote:

On Tue, 22 May 2012 22:28:30 -0700, John Larkin
jjSNIPlarkin@highTHISlandtechnology.com> wrote:

On Tue, 22 May 2012 21:24:50 -0400, "krw@att.bizzzzzzzzzzzz"
krw@att.bizzzzzzzzzzzz> wrote:

On Tue, 22 May 2012 14:49:48 -0700, John Larkin
jlarkin@highlandtechnology.com> wrote:

On Tue, 22 May 2012 11:30:05 -0500, John Fields
jfields@austininstruments.com> wrote:

On Tue, 22 May 2012 08:30:21 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:


You have said that you're not an engineer, and that your electronics
is self-taught. Unless you forced yourself to learn the math, that
puts you at a disadvantage when discussing theory.

One good thing about EE school is that we were forced to learn the
theory and do the math. And we were taught to be careful and check our
work before turning it in. A lot of engineering is about avoiding
risk, and the more complex a system, the more careful you have to be
if it's ever going to work. One reason we can build a very complex
laser controller, and get it to work first-rev, is that we check the
hell out of our stuff before we etch boards. It's a lot of grunt work,
but it pays off.

---
You never miss a chance to spout platitudes and pat yourself on the
back, do you?

There's nothing glorious about grunt-level checking your work. I can
see why you don't do it.

Because he's incapable of checking anything more complicated than a 555?
...even a 240V plug?

I think he's used to doing simple stuff, like 555s and 4000-series
hairball async logic. If it's just a few chips, you can take some
risks and eventually get it to work most of the time. If you've got an
8-layer board with, say, 500 parts, and simulation isn't feasible, and
you allow a 1% risk of messing any one up, let's see, the chance of it
working is 0.99^500, which is under 1%. It might work on the third or
fourth board spin, maybe.

The three boards I've designed this year (for the new PPoE) are all over 1000
components (1000, 1200, and 1500). We'll see how well I did on the first in a
few days (our CM has made a mess of assembly).


That's always scary, the first board.

Indeed.

Do all the parts fit?

Don't know yet. We haven't gotten in back from the CM. I found out this
morning that they're asking about reference designators that don't exist and
parts that are clearly marked as OPEN.

Do the power supplies come up?

Can the uP run code?

Does the FPGA configure?

No FPGAs on this one. I only have one minor CPLD on these.

That's just for starters, but those are milestones.

We always assemble the first articles in-house. That way, we can talk
to the assemblers if any problems come up.

Our only manufacturing capability is in Mexico. We're specifically trying to
avoid using them.

I have toyed with the idea of sending all our PCB assembly to Mexico
or China or Arizona or some other bleak place where labor is cheap.
Assembling electronics in downtown San Francisco is insane. But the
quality would suffer, and so would my people. But I can sure see why
manufacturing, and entire companies, are fleeing the USA and
California in particular.

Up until 2008 they manufactured everything right here (a Japanese company
building electronics in the USA, go figure). When the bottom fell out, they
packed up the entire manufacturing operation and moved it to Mexico. The moved
the prototype line, too, and merged it with manufacturing. If we want to
build a prototype (we build 25 to 50 systems as prototypes) we have to
interrupt the manufacturing line and it can be a six or eight week wait. It's
better, all around, if we keep the work locally. Unfortunately, we didn't
realize the CM was going to ship the work to their parent company in Texas.

If I have to, I can do 2 or 3-day turn on a multilayer PCB, and have
the board assembled and inspected the same day the bare board arrives.
Considering how expensive engineering is, and how valuable
time-to-market is, rapid prototyping is sure worth it.

It's amazing how many PHBs skimp on engineering support: prototyping,
equipment, computers, software, books.


--

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

 

[Ian Field]

"John Fields" <jfields@austininstruments.com> wrote in message
news:tcdtr71d4qqf3hfec9n1r026330cartdak@4ax.com...

On Thu, 24 May 2012 22:19:26 +0100, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:


"John Fields" <jfields@austininstruments.com> wrote in message
news:e88tr75itfk5gh6fsn8nj5n5jo6o3jbd9k@4ax.com...
On Thu, 24 May 2012 20:47:08 +0100, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:


"John Fields" <jfields@austininstruments.com> wrote in message
news:313tr7psmf3d5d261ke6otn17bc4klt95b@4ax.com...
On Thu, 24 May 2012 11:27:20 -0700, John Larkin
jlarkin@highlandtechnology.com> wrote:

On Thu, 24 May 2012 05:37:06 -0500, John Fields
jfields@austininstruments.com> wrote:

On Tue, 22 May 2012 22:28:30 -0700, John Larkin
jjSNIPlarkin@highTHISlandtechnology.com> wrote:

On Tue, 22 May 2012 21:24:50 -0400, "krw@att.bizzzzzzzzzzzz"
krw@att.bizzzzzzzzzzzz> wrote:

On Tue, 22 May 2012 14:49:48 -0700, John Larkin
jlarkin@highlandtechnology.com> wrote:

On Tue, 22 May 2012 11:30:05 -0500, John Fields
jfields@austininstruments.com> wrote:

On Tue, 22 May 2012 08:30:21 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:


You have said that you're not an engineer, and that your
electronics
is self-taught. Unless you forced yourself to learn the math,
that
puts you at a disadvantage when discussing theory.

One good thing about EE school is that we were forced to learn
the
theory and do the math. And we were taught to be careful and
check
our
work before turning it in. A lot of engineering is about
avoiding
risk, and the more complex a system, the more careful you have
to
be
if it's ever going to work. One reason we can build a very
complex
laser controller, and get it to work first-rev, is that we check
the
hell out of our stuff before we etch boards. It's a lot of grunt
work,
but it pays off.

---
You never miss a chance to spout platitudes and pat yourself on
the
back, do you?

There's nothing glorious about grunt-level checking your work. I
can
see why you don't do it.

Because he's incapable of checking anything more complicated than a
555?
...even a 240V plug?

I think he's used to doing simple stuff, like 555s and 4000-series
hairball async logic. If it's just a few chips, you can take some
risks and eventually get it to work most of the time. If you've got
an
8-layer board with, say, 500 parts, and simulation isn't feasible,
and
you allow a 1% risk of messing any one up, let's see, the chance of
it
working is 0.99^500, which is under 1%. It might work on the third
or
fourth board spin, maybe.

---
While I've posted a lot more stuff here than you have - pro bono and
without a lot of fanfare -

And usually wrong the first few times.

---
Even if that were true, which it isn't, so what?

The work gets done, if there are any errors they get fixed, and the
querant goes away happy.


.........well, laughing a lot anyway.

---
On his way to the bank.


You charge for the crap you spout here?!

---
If you think it's crap, then clearly you're in the dark.

But, no.

The querents get to determine whether the solutions I propose work, or
not, and then charge whatever the market will bear for their
implementation and/or sale.

I'm only in the loop at the design end and I divulge the secrets for
free.

You, on the other hand, are a talentless hack who aspires to that
forever elusive adequacy.

--
JF

Doesn't take much to show you up as a fraud then does it.

 

[Jasen Betts]

On 2012-05-24, John Fields <jfields@austininstruments.com> wrote:

On 24 May 2012 11:16:42 GMT, Jasen Betts <jasen@xnet.co.nz> wrote:

On 2012-05-22, John Fields <jfields@austininstruments.com> wrote:
On Tue, 22 May 2012 08:22:47 -0700, John Larkin
---
Here's what I wrote, with the earlier "120V" omission included:

"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
120V mains without changing plugs."

I thought that it would be obvious to anyone schooled in the art that
under the conditions I outlined the load resistance would remain
constant, but such turned out not to be the case.

The path you took to that conclusion is obvious, but it's obviously wrong.

---
It's not obviously wrong to me, so why don't you show the proof?
---

P=VI

The plug's current rating is 15A doubling the voltage from 120V to 240V
can only double the available power from 1800W to 3600W

The load doesn't determine the power available, the supply does that.

---
You must have missed the implied: ..."four times the power available
to the load"...
---

Amount of power available to the load? what does that mean?

Would't it be easier (and safer) to just reduce the load resistance by a
factor of 10 and get 10 times more power from the outlet.

---
Apples and oranges.

makes about as much sense as using a 3600W heater at half voltage.

--
⚂⚃ 100% natural

--- Posted via news://freenews.netfront.net/ - Complaints to news@netfront.net ---

 

[John Fields]

On Fri, 25 May 2012 20:18:40 +0100, "Ian Field"
<gangprobing.alien@ntlworld.com> wrote:

"John Fields" <jfields@austininstruments.com> wrote in message
news:tcdtr71d4qqf3hfec9n1r026330cartdak@4ax.com...
On Thu, 24 May 2012 22:19:26 +0100, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:


"John Fields" <jfields@austininstruments.com> wrote in message
news:e88tr75itfk5gh6fsn8nj5n5jo6o3jbd9k@4ax.com...
On Thu, 24 May 2012 20:47:08 +0100, "Ian Field"
gangprobing.alien@ntlworld.com> wrote:


"John Fields" <jfields@austininstruments.com> wrote in message
news:313tr7psmf3d5d261ke6otn17bc4klt95b@4ax.com...
On Thu, 24 May 2012 11:27:20 -0700, John Larkin
jlarkin@highlandtechnology.com> wrote:

On Thu, 24 May 2012 05:37:06 -0500, John Fields
jfields@austininstruments.com> wrote:

On Tue, 22 May 2012 22:28:30 -0700, John Larkin
jjSNIPlarkin@highTHISlandtechnology.com> wrote:

On Tue, 22 May 2012 21:24:50 -0400, "krw@att.bizzzzzzzzzzzz"
krw@att.bizzzzzzzzzzzz> wrote:

On Tue, 22 May 2012 14:49:48 -0700, John Larkin
jlarkin@highlandtechnology.com> wrote:

On Tue, 22 May 2012 11:30:05 -0500, John Fields
jfields@austininstruments.com> wrote:

On Tue, 22 May 2012 08:30:21 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:


You have said that you're not an engineer, and that your
electronics
is self-taught. Unless you forced yourself to learn the math,
that
puts you at a disadvantage when discussing theory.

One good thing about EE school is that we were forced to learn
the
theory and do the math. And we were taught to be careful and
check
our
work before turning it in. A lot of engineering is about
avoiding
risk, and the more complex a system, the more careful you have
to
be
if it's ever going to work. One reason we can build a very
complex
laser controller, and get it to work first-rev, is that we check
the
hell out of our stuff before we etch boards. It's a lot of grunt
work,
but it pays off.

---
You never miss a chance to spout platitudes and pat yourself on
the
back, do you?

There's nothing glorious about grunt-level checking your work. I
can
see why you don't do it.

Because he's incapable of checking anything more complicated than a
555?
...even a 240V plug?

I think he's used to doing simple stuff, like 555s and 4000-series
hairball async logic. If it's just a few chips, you can take some
risks and eventually get it to work most of the time. If you've got
an
8-layer board with, say, 500 parts, and simulation isn't feasible,
and
you allow a 1% risk of messing any one up, let's see, the chance of
it
working is 0.99^500, which is under 1%. It might work on the third
or
fourth board spin, maybe.

---
While I've posted a lot more stuff here than you have - pro bono and
without a lot of fanfare -

And usually wrong the first few times.

---
Even if that were true, which it isn't, so what?

The work gets done, if there are any errors they get fixed, and the
querant goes away happy.


.........well, laughing a lot anyway.

---
On his way to the bank.


You charge for the crap you spout here?!

---
If you think it's crap, then clearly you're in the dark.

But, no.

The querents get to determine whether the solutions I propose work, or
not, and then charge whatever the market will bear for their
implementation and/or sale.

I'm only in the loop at the design end and I divulge the secrets for
free.

You, on the other hand, are a talentless hack who aspires to that
forever elusive adequacy.

--
JF

Doesn't take much to show you up as a fraud then does it.

---
It takes evidence.

Got some you haven't dreamed up, pipsqueak?

--
JF

 

[John Fields]

On 25 May 2012 21:58:37 GMT, Jasen Betts <jasen@xnet.co.nz> wrote:

On 2012-05-24, John Fields <jfields@austininstruments.com> wrote:
On 24 May 2012 11:16:42 GMT, Jasen Betts <jasen@xnet.co.nz> wrote:

On 2012-05-22, John Fields <jfields@austininstruments.com> wrote:
On Tue, 22 May 2012 08:22:47 -0700, John Larkin
---
Here's what I wrote, with the earlier "120V" omission included:

"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
120V mains without changing plugs."

I thought that it would be obvious to anyone schooled in the art that
under the conditions I outlined the load resistance would remain
constant, but such turned out not to be the case.

The path you took to that conclusion is obvious, but it's obviously wrong.

---
It's not obviously wrong to me, so why don't you show the proof?
---

P=VI

The plug's current rating is 15A doubling the voltage from 120V to 240V
can only double the available power from 1800W to 3600W

The load doesn't determine the power available, the supply does that.

---
You must have missed the implied: ..."four times the power available
to the load"...
---

Amount of power available to the load? what does that mean?

---
The amount of power available from the mains is the product of mains
voltage and maximum current available from the mains, while
the amount of power available to the load will be determined by the
voltage available from the mains and the load's resistance.

For example, if the power available from the mains is 1800 watts and,
because of the load's resistance, only 900 watts is used, then the
power available to the load is 900 watts.
---

Would't it be easier (and safer) to just reduce the load resistance by a
factor of 10 and get 10 times more power from the outlet.

---
Apples and oranges.

makes about as much sense as using a 3600W heater at half voltage.

---
Now you're getting closer.

How much power will a 3600 watt heater dissipate at half voltage?

--
JF