Trying to understand how to design circuits

[John Larkin]

My advice on what to avoid.
1) Don't come on this NG . Most of the regulars and their pals who
have been here for years don't have a clue about what electronics is
about. Avoid them like you'd avoid an epidemic! They are far worse
then that!

2) Never ever read the Art of Electronics. Its the worst book that has
ever been written on the subject.

Cheers

3) Become a plumber so you can fix my remote-controlled pool and spa.

John

 

[Jim Thompson]

3) Become a plumber so you can fix my remote-controlled pool and spa.

John

Bwahahahaha ;-)

...Jim Thompson

 

[lemonjuice]

My advice on what to avoid.
1) Don't come on this NG . Most of the regulars and their pals who
have been here for years don't have a clue about what electronics is
about. Avoid them like you'd avoid an epidemic! They are far worse
then that!

2) Never ever read the Art of Electronics. Its the worst book that has
ever been written on the subject.

Cheers

<<3) Become a plumber so you can fix my remote-controlled pool and spa.

<<John


Would you associate with anyone who can swim so badly that he messes up
his piping system?
Grow up you grannies.

 

[Fred Bloggs]

I am trying to understand the process by which the design of circuits
is carried out.
How from the white paper begins the design of a certain circuit?

In many other areas one understands that there is a certain structure,
a certain order, a process. For example:

In the case of a writing one understands that there is a thesis, main
ideas, ideas of support, a conclusion. All this must be articulated to
achieve a certain objective. This is understandable.

In the case of a car is understood that exists the motor, the electric
system, the chassis, the panel, all they complying a certain function
and thus in many other areas as the software, Civil Engineering, etc.

But in the case of the circuits all seems very confused (at least for
the novice). One doesn`t know how someone decided to put a resistor
here, there a diode, or a capacitor over there. At times seems that
certain circuits were discovered by accident. Which is the center and
which the periphery.

So the question is:
Once one has certain know-how of electronics as the funcion of the
components, the basic theory, etc
¿How to proceed from the white paper to go building a certain circuit?

How to decide where to put a resistor, a diode, a capacitor, etc?

There is no short answer. There are two books available that tackle this
very question at the entry level:
Electronics: A Systems Approach , Storey and
Gateway to Electronics, Dunn

 

[John Larkin]

There is no short answer. There are two books available that tackle this
very question at the entry level:
Electronics: A Systems Approach , Storey and
Gateway to Electronics, Dunn

I just hate book titles like "Bicycles: a Peddling Approach." And
journal article titles containing the word "Novel."

John

 

[Rick]

Stuff snipped

I just hate book titles like "Bicycles: a Peddling Approach." And
journal article titles containing the word "Novel."

John

I was going to suggest "The Feng Shui of Electronics" by Pau Horowiti
and Wan Hio

 

[John Larkin]

Stuff snipped



I was going to suggest "The Feng Shui of Electronics" by Pau Horowiti
and Wan Hio

This book comes highly recommended:

http://bric-a-brac.org/humour/images/wal_grom/electronics.jpg


John

 

[Paul Burridge]

The difference is the entire philosophy on constructing a work. Electronics
is highly scientific, and as such comes from a methodic progression of ideas
and constructions, connected together. The real art is connecting the
proper building blocks together to accomplish a given function.

I can't agree with that, Tim. Joining up the dots between a block
diagram is the easy bit. What have you got to factor in? Signal levels
and source and load impedances and that's about it. Designing the
blocks themselves at component level is the really clever bit IMV.

 

[Jim Thompson]

Stuff snipped



I was going to suggest "The Feng Shui of Electronics" by Pau Horowiti
and Wan Hio

Sno-o-o-o-ort ;-)

...Jim Thompson

 

[Paul Burridge]

If you want to learn to write, you have to write a lot. If you want to
learn how to play tennis, play tennis a lot. Circuit design is
creation, not analysis, so there's no formula. A white paper (app
note?) can be instructive about a part, but isn't often a proper basis
for a design. If it was, nobody would need designers.

How much design is truly novel nowadays? I mean, if you want an
oscillator - to take just one example - there are loads of eponymous
configurations to choose from, mostly dating from 60+ years ago.
Other staples have likewise been refined and settled over the decades.
The only 'design' as such remaining to be done is hooking up the
various sub-circuit elements, AFAICS. There's no point in re-inventing
the wheel, so how often does a currently working designer actually sit
down and truly design/develop a totally novel configuration?

 

[Paul Burridge]

I can't sit by and see such a grave injustice go answered. If the
regular designers here are guilty of *anything* it's only forgetting
how tough a subject this is to get to grips with adequately. There are
plenty of demonstrably genuine experts here. I smell a troll
hereabouts...

Rubbish. It's one of the very best!
Like I said: a troll.

 

[Kevin Aylward]

On Tue, 27 Dec 2005 08:20:18 GMT, "Kevin Aylward"


That's not design,

It is, its:

1 Replication (copying)
2 Randam variation
3 Selection

Thats it mate. End of story.

Ho humm... I have explained this many times, as I am sure you know, but
to refresh,

http://www.anasoft.co.uk/replicators/intelligence.html check out the
"Electronic Engineer as a Darwinian machine" bit.

It's not fun, and it's usually not
very profitable, because if you can do it, everybody else can, too.

Sorry to bust your bubble John, but that *is* the way it is, and the
method is very profitable. Indeed, its essentially the only way to make
profit.

The problem here is that people like to lie to themselves. You need to
stand back and understand what it is one really does, not what one would
like to believe they do.

I design *new* products every day. I do it using the same *old*
components like diff pairs, cascodes, folded cascades, push pull stages
etc that were invented at the beginning of electronics. It will always
be that way. Don't kid yourself any different, but please do let me know
when you invent a ultracascideconduit.

Or take the other path, make every design insanely great.

Completely pointless.

Kevin Aylward
[email protected]
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

 

[Fred Bloggs]

I just hate book titles like "Bicycles: a Peddling Approach." And
journal article titles containing the word "Novel."

John

Those books are not for you, they are for beginners, written well and
comprehensive, more like surveys than textbooks, although they do
contain problem sets.

 

[John Larkin]

How much design is truly novel nowadays? I mean, if you want an
oscillator - to take just one example - there are loads of eponymous
configurations to choose from, mostly dating from 60+ years ago.

Well, in the last few years, I've designed six or eight different
oscillators, all with topologies I've never seen elsewhere. Of course,
I can't guarantee that nobody has ever done any of them before. Except
two, maybe three, that I'm pretty sure about.

Other staples have likewise been refined and settled over the decades.
The only 'design' as such remaining to be done is hooking up the
various sub-circuit elements, AFAICS. There's no point in re-inventing
the wheel,

Sure there is. New applications and new components invite new
topologies. Besides, inventing new circuits is fun.

so how often does a currently working designer actually sit
down and truly design/develop a totally novel configuration?

I think there's lots of room for, and need for, both new circuits and
new product architectures.

John

 

[Joel Kolstad]

I can't agree with that, Tim. Joining up the dots between a block
diagram is the easy bit. What have you got to factor in? Signal levels
and source and load impedances and that's about it. Designing the
blocks themselves at component level is the really clever bit IMV.

One of the chapters in "The Art & Science of Analog Circuit Design" describes
how, for a mercury delay line memory, the "hook up the blocks" approach was
unable to provide a working design; designing all the blocks "in paralle"
allowed for a very inexpensive solution.

The vast majority of engineers out there are of the "hook up the blocks"
variety; it is much easier than designing the blocks themselves!

 

[John Larkin]

Hi all:

I am trying to understand the process by which the design of circuits
is carried out.
How from the white paper begins the design of a certain circuit?

In many other areas one understands that there is a certain structure,
a certain order, a process. For example:

In the case of a writing one understands that there is a thesis, main
ideas, ideas of support, a conclusion. All this must be articulated to
achieve a certain objective. This is understandable.

In the case of a car is understood that exists the motor, the electric
system, the chassis, the panel, all they complying a certain function
and thus in many other areas as the software, Civil Engineering, etc.

But in the case of the circuits all seems very confused (at least for
the novice). One doesn`t know how someone decided to put a resistor
here, there a diode, or a capacitor over there. At times seems that
certain circuits were discovered by accident. Which is the center and
which the periphery.

So the question is:
Once one has certain know-how of electronics as the funcion of the
components, the basic theory, etc
¿How to proceed from the white paper to go building a certain circuit?

How to decide where to put a resistor, a diode, a capacitor, etc?

Thanks in advance by any comment.

Barrie Gilbert did a chapter in Jim Williams' first (1991) Analog
Circuit Design book[1], where he talks about this very issue, "Where
do little circuits come from?" Highly recommended, his bit and the
whole book.

John

[1] my copy of which, improbably, is autographed by Bob Pease.

 

[Riscy]

I just ignore the silly response from the oldies like them.

I recommends reading many good electronics books and learn about basic
thing such as transistor, resistor and capacitor. The important thing
is to spend time experimenting and interacting with electronics and see
the response. The shopping list includes soldering irons, scope, PSU
(battery is cheaper but don't last long) and digital voltmeter (DVM).
There is maplins 200:1 electronics kits which give you very good start.
You can get equipment cheaply from ebay but don't expects perfect
accuarcy or performance, but you still get out from them.

The book need to be easy to following with simple equation to start
with. Once you understand the basic equation and theory, you can
advance into op-amp and feedback levels. Then you progress into more
complex domains such as ADC, DAC and serial interface. You could start
involving Microchip PIC and C programming but don't let this dent you
or being afriad of it. Once you done this you can declare yourself as
designer engineer(!) which would turn your dream into wonderful
realities(!).

All this is more like investment of your skill and treat as part of
hobbies, otherwise you simply walk away, watch TV and drink beers or
popcorns and hope to die knowing nothing.

I work as Analogue Design Engineer and earning nice income from it, I
do hobby from time to time in embedded design engineer because that is
where digital meet analogue.

Hope this help...

Good luck.

Riscy

 

[Joel Kolstad]

I just ignore the silly response from the oldies like them.

I wouldn't. The path you describe works fine if you want to be a board level
or digital designer, but there's no getting away from a decent dose of math
and knowledge of some fairly sophisticated device models if you're looking to
design to build those "small blocks" like Jim Thompson, Winfield Hill, and
others do.

Once you understand the basic equation and theory, you can
advance into op-amp and feedback levels. Then you progress into more
complex domains such as ADC, DAC and serial interface.

Knowing how to interface an ADC or DAC over a serial interface is arguably
trivial compared to having an in-depth understanding of op-amps and feedback.

Granted, for every Jim or Win out there there are probably 1,000 or more
"block level" design engineers, and the number is increasing all the time.
Still, it's important to have a decent idea of "what I know" vs. "what _is_
there to know?" I.e., you should have some vague idea as to just how little
you know. Personally, I know that I couldn't begin to design a lot of the
stuff that those "oldies" can!

 

[Kevin Aylward]

Hi all:

I am trying to understand the process by which the design of circuits
is carried out.
How from the white paper begins the design of a certain circuit?

In many other areas one understands that there is a certain
structure, a certain order, a process. For example:

In the case of a writing one understands that there is a thesis, main
ideas, ideas of support, a conclusion. All this must be articulated
to achieve a certain objective. This is understandable.

In the case of a car is understood that exists the motor, the
electric system, the chassis, the panel, all they complying a
certain function and thus in many other areas as the software, Civil
Engineering, etc.

But in the case of the circuits all seems very confused (at least for
the novice). One doesn`t know how someone decided to put a resistor
here, there a diode, or a capacitor over there. At times seems that
certain circuits were discovered by accident. Which is the center and
which the periphery.

So the question is:
Once one has certain know-how of electronics as the funcion of the
components, the basic theory, etc
¿How to proceed from the white paper to go building a certain
circuit?

How to decide where to put a resistor, a diode, a capacitor, etc?

Thanks in advance by any comment.

Barrie Gilbert did a chapter in Jim Williams' first (1991) Analog
Circuit Design book[1], where he talks about this very issue, "Where
do little circuits come from?" Highly recommended, his bit and the
whole book.

*ALL* "new" design is a randam variation from an existing design.

If the design were *all* new, it would have say, no diff pairs, no
cascods, no source followers no etc, that is, it could only be an
aimless connection of component terminals, and could not possible
achieve anything.

If the new design had no random component, it would, by definition, be
derivable from existing designs, in which case it couldn't be genuinely
new. Random generation is the only way to produce a non derivable
result. If it is random then we have no control over it, by definition.
Its random. The brain is a Darwinian machine, and that is how it
produces "new" designs. Copying, Selection and Randam variation is all
there is.

John, you seen to think that there is merit in coming up with something
new. Why? The brain can only do this by a random process, so what's
superior about generating something by accident? For example, it way
harder to copy a complicated arpeggio and play it fast, then to generate
new music. Its piss easy to hit some random notes on a piano.

Kevin Aylward
[email protected]
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

 

[Kevin Aylward]

Well, in the last few years, I've designed six or eight different
oscillators, all with topologies I've never seen elsewhere.

With all due respect John, I would have to see *proof* that such "new"
topologies actually were superior to the well trusted existing ones.

The number of times I have examined "new" circuits that actually achieve
no net benefit from an existing circuit are too numerous to mention.
There are many convoluted designs that achieve precisely, nothing. Most
people fool themselves. It is very hard to be objective about ones own
work.

Of course,
I can't guarantee that nobody has ever done any of them before. Except
two, maybe three, that I'm pretty sure about.

Its very unlikely that anyone can come up, today, with a real useful
topology that hasn't already been looked at. Sure, it does happen, but
not very often. Too many people have looked at this stuff for way too
long.

Sure there is.

Don't be daft. If its already invented, it invented. End of story.

New applications and new components invite new
topologies. Besides, inventing new circuits is fun.


I think there's lots of room for, and need for, both new circuits and
new product architectures.

I don't. The opportunity for a really new circuit that actually has new
value is < 1:1000.

Kevin Aylward
[email protected]
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.