Getting started with electronics? :)

[TonyS]

On 24/01/2012 5:39 AM, Tom Del Rosso wrote:

spamtrap1888 wrote:

Let people get a good working understanding of things before you drown
them with abstractions. Thank goodness when I first became interested
in electronics, no one sat me down and emphasized the difference
between the abvolt and the statvolt.

I didn't say anything like that at all. I said resistance is defined in
terms of voltage and current, not the other way around, and if you aren't
ready to define voltage then just don't do it.

You can omit lots of things without being compelled to teach something that
isn't so, but most "science" teachers think the resistor color code is the
root of everything.

And lots of abstrations are taught to 5-year-olds, like the concept of time.
You don't have to teach them SR. You just teach them how things are
affected by time. But you don't teach them that the clock makes time
happen, do you?

Kids are more capable of learning abstractions than adults. Adults assume
incorrectly that kids need an explanation for abstractions, so they provide
one that is wrong and make learning harder rather than easier.


That's how it's explained:

https://plus.google.com/photos/110446129519984863552/albums/5672660195642074977

 

[spamtrap1888]

On Jan 23, 6:23 pm, TonyS <nos...@mymail.com> wrote:

On 24/01/2012 5:39 AM, Tom Del Rosso wrote:







spamtrap1888 wrote:

Let people get a good working understanding of things before you drown
them with abstractions. Thank goodness when I first became interested
in electronics, no one sat me down and emphasized the difference
between the abvolt and the statvolt.

I didn't say anything like that at all.  I said resistance is defined in
terms of voltage and current, not the other way around, and if you aren't
ready to define voltage then just don't do it.

You can omit lots of things without being compelled to teach something that
isn't so, but most "science" teachers think the resistor color code is the
root of everything.

And lots of abstrations are taught to 5-year-olds, like the concept of time.
You don't have to teach them SR.  You just teach them how things are
affected by time.  But you don't teach them that the clock makes time
happen, do you?

Kids are more capable of learning abstractions than adults.  Adults assume
incorrectly that kids need an explanation for abstractions, so they provide
one that is wrong and make learning harder rather than easier.

That's how it's explained:https://plus.google.com/photos/110446129519984863552/albums/567266019...

Where are the coulombs and joules in that drawing?

The best way to explain three new concepts is not by adding two more
new concepts.

Drilling down to bedrock is not always the best way to learn
something. As a kid, the current convention always bothered me,
because I knew current was a flow of electrons, and electrons went the
other way. Did current reflect a hole-centric way of looking at
things?

But then I realized electrons were irrelevant to my study of current
flow. They're important to a deeper understanding of electronics, but
if you're not operating at that level they just get in the way.

 

[spamtrap1888]

On Jan 23, 1:39 pm, "Tom Del Rosso" <td...@verizon.net.invalid> wrote:

spamtrap1888 wrote:

Let people get a good working understanding of things before you drown
them with abstractions. Thank goodness when I first became interested
in electronics, no one sat me down and emphasized the difference
between the abvolt and the statvolt.

I didn't say anything like that at all.  I said resistance is defined in
terms of voltage and current, not the other way around, and if you aren't
ready to define voltage then just don't do it.

I don't think you sufficiently understand voltage. Explain to me the
difference between the abvolt and the statvolt, to prove me wrong.

You can omit lots of things without being compelled to teach something that
isn't so, but most "science" teachers think the resistor color code is the
root of everything.

And lots of abstrations are taught to 5-year-olds, like the concept of time.
You don't have to teach them SR.  You just teach them how things are
affected by time.  But you don't teach them that the clock makes time
happen, do you?

You don't start by teaching them about the leap second if you want
them to learn about the big hand and the little hand. Similarly they
don't need to know about how the earth wobbles on its access to know
when it's a quarter to five.

Kids are more capable of learning abstractions than adults.  Adults assume
incorrectly that kids need an explanation for abstractions, so they provide
one that is wrong and make learning harder rather than easier.

Don't make up stuff, but don't teach them more than they can absorb.
If some kid asks how an airplane flies, you don't need to start your
explanation by teaching him tensor mathematics.

 

[Nelson]

On Mon, 23 Jan 2012 21:23:10 -0500, TonyS wrote
(in article <z7SdncKf0ZCQi4PSnZ2dnUVZ_qqdnZ2d@westnet.com.au&gt:

That's how it's explained:

https://plus.google.com/photos/110446129519984863552/albums/567266019564

207497

7

I love it

--
Nelson

 

[Nelson]

On Tue, 24 Jan 2012 03:23:58 -0500, spamtrap1888 wrote
(in article
<11492bf9-55fd-41c2-b86d-5c65c9d65202@q7g2000pbg.googlegroups.com&gt:

[Snip]

Where are the coulombs and joules in that drawing?

The best way to explain three new concepts is not by adding two more
new concepts.

Drilling down to bedrock is not always the best way to learn
something. As a kid, the current convention always bothered me,
because I knew current was a flow of electrons, and electrons went the
other way. Did current reflect a hole-centric way of looking at
things?

I still find myself occasionally getting momentarily hung up on this...
and I have Master's Degrees in Electrical Engineering and Physics
I have always found "holes" counterintuitive. It's too bad the
conventions didn't evolve so that they were consistent with the
underlying physics. It's as if we defined the basic unit of heat as
the "friggie" so that when a body heated up, we would say it lost so
many friggies.

--
Nelson

 

[William Sommerwerck]

"Nelson" <nelson@nowhere.com> wrote in message
news:0001HW.CB440105043D41B1B02919BF@news.astraweb.com...

On Tue, 24 Jan 2012 03:23:58 -0500, spamtrap1888 wrote
(in article
11492bf9-55fd-41c2-b86d-5c65c9d65202@q7g2000pbg.googlegroups.com&gt:

Drilling down to bedrock is not always the best way to learn
something. As a kid, the current convention always bothered me,
because I knew current was a flow of electrons, and electrons
went the other way. Did current reflect a hole-centric way of looking
at things?

No. See below.

I still find myself occasionally getting momentarily hung up on this...
and I have Master's Degrees in Electrical Engineering and Physics
I have always found "holes" counterintuitive. It's too bad the
conventions didn't evolve so that they were consistent with the
underlying physics. It's as if we defined the basic unit of heat as
the "friggie" so that when a body heated up, we would say it lost so
many friggies.

Positive and negative, as you point out, are misnamed. This is supposedly
the fault of B. Franklin, who said that electrical particles flowed from an
source with an excess to a sink with fewer -- which is basically correct. He
called the excess side "positive", not knowing that the charge of the
electrical particles would eventually be called "negative".

BY CONVENTION, current flows from positive to negative. This has never much
bothered me, nor has hole flow. (A hole is a place in the lattice where an
electron "should" be.)

Now, if someone could explain exactly how -- on a quantum level -- junction
transistors work -- I would be delighted. I've yet to find a book that makes
it clear. (FETs are easy.)

 

[Tom Del Rosso]

spamtrap1888 wrote:

On Jan 23, 1:39 pm, "Tom Del Rosso" <td...@verizon.net.invalid> wrote:
spamtrap1888 wrote:

Let people get a good working understanding of things before you
drown them with abstractions. Thank goodness when I first became
interested in electronics, no one sat me down and emphasized the
difference between the abvolt and the statvolt.

I didn't say anything like that at all. I said resistance is
defined in terms of voltage and current, not the other way around,
and if you aren't ready to define voltage then just don't do it.

I don't think you sufficiently understand voltage. Explain to me the
difference between the abvolt and the statvolt, to prove me wrong.

They're just different units. Convert by multiplying by a constant. That's
all. It's like using the bell instead of the decibel or microns instead of
angstroms. That's not a big deal.

You don't start by teaching them about the leap second if you want
them to learn about the big hand and the little hand. Similarly they
don't need to know about how the earth wobbles on its access to know
when it's a quarter to five.

Which has nothing to do with avoiding teaching them something that's wrong.

Resistance is not a fundamental quantity. It's nothing but the ratio of
voltage and current, and only when measured in the absence of other factors
which are fundamental, so it's not something you should refer to when
explaining voltage.

The last sentence in the cited web page could simply be deleted and nothing
would be lost. I'm baffled why you think it's so important to include it.


--

Reply in group, but if emailing add one more
zero, and remove the last word.

 

[Tom Del Rosso]

spamtrap1888 wrote:

Drilling down to bedrock is not always the best way to learn
something.

You can never reach bedrock.

As a kid, the current convention always bothered me,
because I knew current was a flow of electrons, and electrons went the
other way. Did current reflect a hole-centric way of looking at
things?

So you just think of current as an abstraction. You don't think about
holes. You didn't need to learn (at first) about holes. But you also
didn't need to learn a lie about positive particles. It can just be left as
an abstraction. So can voltage.


--

Reply in group, but if emailing add one more
zero, and remove the last word.

 

[Tom Del Rosso]

spamtrap1888 wrote:

Where are the coulombs and joules in that drawing?

Coulombs and joules are in the other drawing, in the web page in question.
They were included without naming them in an abstract and intuitive way.
Then the author went off in the wrong direction when he should have just
left it as an abstraction.


--

Reply in group, but if emailing add one more
zero, and remove the last word.

 

[josephkk]

On Tue, 24 Jan 2012 00:23:58 -0800 (PST), spamtrap1888
<spamtrap1888@gmail.com> wrote:

<snip>

Kids are more capable of learning abstractions than adults.  Adults assume
incorrectly that kids need an explanation for abstractions, so they provide
one that is wrong and make learning harder rather than easier.

Do not be too quick to judge on that. Mostly learning it wrong first is
the real stumbling block rather than abstraction itself. Learning formal
abstraction is a different issue, and needs to be treated as such.

That's how it's explained:https://plus.google.com/photos/110446129519984863552/albums/567266019...

Where are the coulombs and joules in that drawing?

The best way to explain three new concepts is not by adding two more
new concepts.

Drilling down to bedrock is not always the best way to learn
something. As a kid, the current convention always bothered me,
because I knew current was a flow of electrons, and electrons went the
other way. Did current reflect a hole-centric way of looking at
things?

But then I realized electrons were irrelevant to my study of current
flow. They're important to a deeper understanding of electronics, but
if you're not operating at that level they just get in the way.

What happened was merely an incorrect A|B choice long before there was
anything enough information to decide correctly. But it has been embedded
in the ASSumptions for hundreds of years and there is no reasonable way of
correcting it. Not that electrons move in conductors at anything like
light speed.

?-)

 

[spamtrap1888]

On Jan 24, 7:32 am, "Tom Del Rosso" <td...@verizon.net.invalid> wrote:

spamtrap1888 wrote:
On Jan 23, 1:39 pm, "Tom Del Rosso" <td...@verizon.net.invalid> wrote:
spamtrap1888 wrote:

Let people get a good working understanding of things before you
drown them with abstractions. Thank goodness when I first became
interested in electronics, no one sat me down and emphasized the
difference between the abvolt and the statvolt.

I didn't say anything like that at all. I said resistance is
defined in terms of voltage and current, not the other way around,
and if you aren't ready to define voltage then just don't do it.

I don't think you sufficiently understand  voltage. Explain to me the
difference between the abvolt and the statvolt, to prove me wrong.

They're just different units.  Convert by multiplying by a constant.  That's
all.  It's like using the bell instead of the decibel or microns instead of
angstroms.  That's not a big deal.

That's like saying a pound is a unit of mass. Try again.

You don't start by teaching them about the leap second if you want
them to learn about the big hand and the little hand. Similarly they
don't need to know about how the earth wobbles on its access to know
when it's a quarter to five.

Which has nothing to do with avoiding teaching them something that's wrong.

Resistance is not a fundamental quantity.  It's nothing but the ratio of
voltage and current, and only when measured in the absence of other factors
which are fundamental, so it's not something you should refer to when
explaining voltage.

What do you mean by fundamental property? Resistance (more precisely,
resistivity) is a materials property, as is potential difference. If I
make a cell (defining the voltage) and apply it to a hunk of material
(geometry plus a property of the material), that defines the current
that flows through the material.

 

[Nelson]

On Wed, 25 Jan 2012 01:20:52 -0500, spamtrap1888 wrote
(in article
<a5498ae8-19fa-42fd-8ca1-f6fbce9be30d@y5g2000pbk.googlegroups.com&gt:

What do you mean by fundamental property? Resistance (more precisely,
resistivity) is a materials property

I could swear I recall deriving resistivity from the fundamental
properties of the material in question such as it's crystalline
structure, electron scattering cross-section, temperature, etc.
Quantum Thermodynamics or something. It was a very long time ago

Since neither "voltage" nor "current" are inherent properties of
materials, resistivity would seem, to me at least, be the more
"fundamental" property.

As an analogy, you can define mass as the ratio of applied force to
acceleration, but I think most people would say that mass continues to
exist in the absence of force and acceleration and hence is a
fundamental property.

--
Nelson

 

[Ian Field]

"Woei Shyang" <nntp-terranews@w.woeishyang.com> wrote in message
news:2012012010200729084-nntpterranews@wwoeishyangcom...

Hi,

I'm completely new to electronics, but I'd like to get started.

Perhaps it is just me getting tired of this wasteful culture where devices
are disposable, or just me being a tightwad, but I'd really love to learn
how to repair my own stuff, and know how various little DIY projects
actually work as opposed to putting them blindly together.

Are there any books that you guys might recommend to help me get started?

I've always been a software person by training and trade, so you can say I
have absolutely no background in this, except for being a geek.

Thanks for any tips and recommendations

The group: alt.binaries.e-book.technical has the book; Starting Electronics
4th ed K. brindley Newnes 2011 you can download free right now.