Some general questions on learning electronics

[zalzon]

Hello,
I've always dreamt of inventing little gadgets & gizmos so
one day, I started on an introductory electronics course (found on
twysted-pair's website).

Though I am determined, learning electronics is a little tougher than
I expected.

Now for the questions :

1) Do you think the course I am learning gives me most if not all of
what i need so far as analog electronics goes? Please take a look at
the lesson topics :

http://www.twysted-pair.com/downloads.htm

Do those topics cover all the essentials of analog electronics or is
there another motherload of theory to absorb once I'm done with that.

2) Do electronic engineers building say robots or cell phones use
mostly analog or mostly digital electronic components in their gizmos?
Does industry require electronic technicians/engineers with mostly
analog or digital skills?

3) Are there a certain number of important circuits which are commonly
used in design of electronic circuits. Could you list them.

4) When you look at a complex schematic, where does your eye look
first? How do you analyse what is happening in the middle of the
circuit for instance? Do you start at the power supply and move to
the middle. Do you "chase the flow of electrons" in the circuit to
understand what's going on at every point. Or do u take a nebulous
view of it? Or do u view it in blocks and say 'here's the common
emitter amplifier', 'here's the full wave bridge rectifier', here's
the whatever..etc. ?

5) I often see current being represented as a flow from + to - and the
direction of the arrow is usually that way in text books. Whereas I
tend to think of current as a flow of electrons from the ground up to
the positive. Is this wrong?

6) Are microchips, fpga, asics..etc all based on the same principles
of analog electronics. I know there are transistors on a microchip
but are the principle of operations the same as how I"m learning it?

I have more questions but I'll stop here.

Thanks, i hope these are not silly questions.

 

[Tom MacIntyre]

On Mon, 04 Aug 2003 10:03:29 GMT, zalzon
<zalzonishappy@thisisnotzalzon.com> wrote:

Hello,
I've always dreamt of inventing little gadgets & gizmos so
one day, I started on an introductory electronics course (found on
twysted-pair's website).

Though I am determined, learning electronics is a little tougher than
I expected.

Now for the questions :

1) Do you think the course I am learning gives me most if not all of
what i need so far as analog electronics goes? Please take a look at
the lesson topics :

http://www.twysted-pair.com/downloads.htm

I am out of the field pretty much now, but here is a list of sites
that, at least at a cursory glance, satisfied me. Although they aren't
in any particular order, note the first one.

http://www.twysted-pair.com/
http://pneuma.phys.ualberta.ca/~gingrich/phys395/notes/phys395.html
http://atschool.eduweb.co.uk/trinity/elec2.html
http://www.sweethaven.com/acee/
http://www.physics.uoguelph.ca/tutorials/ohm/index.html
http://ourworld.compuserve.com/homepages/g_knott/
http://home.wxs.nl/~heuvelvdg/electronics/schematics.html
http://www.cabl.com/restaurant/electronics.html
http://zebu.uoregon.edu/1997/ph161/l2.html
http://www.electronicstheory.com/
http://www.ibiblio.org/obp/electricCircuits/
http://www.electronics-tutorials.com/
http://www.tpub.com/neets/
http://www.tpub.com/index.htm
http://pcdi-homestudy.com/courses/el/outline.html

Tom

 

[Jonathan Kirwan]

On Mon, 04 Aug 2003 10:03:29 GMT, zalzon
<zalzonishappy@thisisnotzalzon.com> wrote:

Hello,
I've always dreamt of inventing little gadgets & gizmos so
one day, I started on an introductory electronics course (found on
twysted-pair's website).

Though I am determined, learning electronics is a little tougher than
I expected.

Now for the questions :

1) Do you think the course I am learning gives me most if not all of
what i need so far as analog electronics goes? Please take a look at
the lesson topics :

http://www.twysted-pair.com/downloads.htm

Do those topics cover all the essentials of analog electronics or is
there another motherload of theory to absorb once I'm done with that.

It doesn't look at all complete. All the way through the last
one looks more like the first few chapters of a good book on the
subject. It *may* be as complete as Heathkit's old 4-volume
coverage, but I can't tell since I can't look at the for-fee
courses.

2) Do electronic engineers building say robots or cell phones use
mostly analog or mostly digital electronic components in their gizmos?
Does industry require electronic technicians/engineers with mostly
analog or digital skills?

These days, I doubt you can perform electronics engineer work
without knowledge in both -- mixed signal design is increasingly
difficult to avoid. And to remain competitive, you may need to
find the right balance between these two. Cell phones, in fact,
are an excellent example of this.

3) Are there a certain number of important circuits which are commonly
used in design of electronic circuits. Could you list them.

I don't think it's possible to list the important circuits. But
I'm no expert anyway, so I'd probably miss a great many of them.

4) When you look at a complex schematic, where does your eye look
first? How do you analyse what is happening in the middle of the
circuit for instance? Do you start at the power supply and move to
the middle. Do you "chase the flow of electrons" in the circuit to
understand what's going on at every point. Or do u take a nebulous
view of it? Or do u view it in blocks and say 'here's the common
emitter amplifier', 'here's the full wave bridge rectifier', here's
the whatever..etc. ?

Schematics are, generally, supposed to be laid out to aid your
understanding. But quite often, I think, they aren't. Instead,
they will often endeavor to highlight the mechanical connections
between components, for example. Or something else, such as
just plain slippiness or else tracings from a PCB layout without
bothering to reshape it for good reading, later.

So the first thing I usually do, if it isn't already dead simple
and can be read easily as it stands, is to see if they've done
the more basic things in drawing the schematic. Some things are
just plain useful in helping to unwind a Gordian Knot, even when
you don't understand it. For example, making electron flow go
from bottom to top and re-arranging the components to achieve
this. That can be done without really knowing what the circuit
does. Another is to arrange signal flow (or what you imagine as
signal flow) to go left to right (and maybe right to left, if it
is feedback.) Actually, these two go hand in hand, since as you
get the electron flow worked out, the signal flow will mostly
straighten itself out, as well. Or you'll have a lot more clues
about that. Once that is done, you are miles ahead.

You also need to be familiar with basic patterns. These may be
things like "wilson mirrors" or "cascodes" or the various
common-emitter/collector/base configurations for transistors.
Or just your basic RC filter. Or a simple peak detector with a
diode and cap. Stuff like that. Just get as familiar as
possible with a lot of simple combinations of small numbers of
components.

Books help a lot, here. I suppose tutorials, too. They can put
various common arrangements in front of you so that you develop
a familiarity with these patterns. A highly skilled electronics
engineer will have a very large repertoire of these design
patterns in their heads and will be able to pick them out in
even poorly drawn schematics -- because they've "been there,
done that" so many times.

Also, don't just learn theory. Get a power supply. Get a volt
meter. Get some tools and parts and build some of these things
and then play with them. Start with something in a book or
diagram and then Vary stuff they didn't tell you about and see
what happens. Experiment, ask yourself "why," and then work at
'understanding' the reasons.

5) I often see current being represented as a flow from + to - and the
direction of the arrow is usually that way in text books. Whereas I
tend to think of current as a flow of electrons from the ground up to
the positive. Is this wrong?

Just be consistent. It's almost never an issue, except in
semiconductors where there is a difference between electron flow
and hole motion, majority and minority carriers, for example.

6) Are microchips, fpga, asics..etc all based on the same principles
of analog electronics. I know there are transistors on a microchip
but are the principle of operations the same as how I"m learning it?

As far as I'm aware, almost always. At low enough levels, there
are quantum effects (such as the fact that photons are bosons
and have a "clumping effect" noticeable at very low levels.)
But at almost any reasonable level, it's all analog stuff. If
you look at the schmidt trigger input circuit, say a simple one
with two transistors, you'll see how analog is used with
positive feedback to make things appear rather digital.
'Excessively' high gain is another way to get there, too.

Bear in mind that I'm only a hobbyist, though. I've nothing
like the experience of many here or elsewhere. So this is just
my little slice of the world and it's not much of a slice, at
all.

Jon

 

[Gerry Ashton]

I'll comment on some of your questions.

"zalzon" <zalzonishappy@thisisnotzalzon.com> wrote in message
news:7l8siv41s8dm2av338avns6fororpnj7u9@4ax.com...
..
..
..

2) Do electronic engineers building say robots or cell phones use
mostly analog or mostly digital electronic components in their gizmos?
Does industry require electronic technicians/engineers with mostly
analog or digital skills?
Everything seems to be moving more and more towards digital, although,

the higher the frequency and the higher the power, the more you still see
analog. Also, even when working with digital circuits, you may need
analog skills and measurements to see if the digital circuit is working
properly.

4) When you look at a complex schematic, where does your eye look
first? How do you analyse what is happening in the middle of the
circuit for instance? Do you start at the power supply and move to
the middle. Do you "chase the flow of electrons" in the circuit to
understand what's going on at every point. Or do u take a nebulous
view of it? Or do u view it in blocks and say 'here's the common
emitter amplifier', 'here's the full wave bridge rectifier', here's
the whatever..etc. ?

I look at it at as high a level as I can. I just think about the general
function
of a part of the schematic if I can, I think of it as blocks (common emitter
amplifier) when I need to, and finally look at the details of the voltages
and currents after I have narrowed things down to the area of interest.

5) I often see current being represented as a flow from + to - and the
direction of the arrow is usually that way in text books. Whereas I
tend to think of current as a flow of electrons from the ground up to
the positive. Is this wrong?

Both ways of thinking are useful; be prepared to think in different ways.

6) Are microchips, fpga, asics..etc all based on the same principles
of analog electronics. I know there are transistors on a microchip
but are the principle of operations the same as how I"m learning it?

It often takes less space to build transistors than resistors or capacitors,
so many solutions will have a greater number of transistors than in a
discrete circuit. Also, transistors, especially bipolar transistors, tend to
be well-matched when they are close to each other on a chip, so some
circuits depend on this match; the same circuit might not work with
two discrete transistors pulled at random from a parts bin.

Gerry Ashton