Schematics & standards

[David Nebenzahl]

Someone else made a comment in another thread here about weird
schematics (like for home appliances).

Wanted to get a small discussion going on that topic. My take: there are
good and bad standards for schematics. Personally, I can't stand the
ones that use rectangle shapes for resistors, instead of the traditional
zigzag that [insert name of deity here] intended to be used. (And even
here there are lots of variations, like old-fashioned schematics that
took this symbol rather literally and sometimes had ten or twelve zigs
and zags, as if an actual resistor was being constructed on paper).

Likewise the wire-connecting/jumping convention: here I much prefer the
modern approach, which is to use a dot for a connection and no dot for
no connection, rather than the clumsy "loop" to indicate one wire
jumping over another with no connection.

Regarding resistor values: Who the hell came up with that new way of
specifying resistance values, like "10R" "or 5K6" or whatever? And why
use this system? I've always used the plain value of the resistance: 10,
56, 5.6K, 56K, etc. Simple, obvious, requires no interpretation. Is this
some kind of Euro thing?

In general, some schematics just look and feel nicer than others. A
well-drawn schematic is a pleasure to read. A bad one--lines too thin or
too thick, misshapen symbols, idiosyncratic interpretations, etc., just
don't look right.

Feel free to add your own schematic pet peeves here.


--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

 

[Falk Willberg]

Am 18.06.2010 22:18, schrieb David Nebenzahl:

Someone else made a comment in another thread here about weird
schematics (like for home appliances).

Wanted to get a small discussion going on that topic. My take: there are
good and bad standards for schematics. Personally, I can't stand the
ones that use rectangle shapes for resistors, instead of the traditional
zigzag that [insert name of deity here] intended to be used...

I prefer the traditional (German?) rectangle shape for resistors, your
zigzag things too much look like inductors, Herr Nebenzahl ;-)

Likewise the wire-connecting/jumping convention: here I much prefer the
modern approach, which is to use a dot for a connection and no dot for
no connection, rather than the clumsy "loop" to indicate one wire
jumping over another with no connection.

Same here.

Regarding resistor values: Who the hell came up with that new way of
specifying resistance values, like "10R" "or 5K6" or whatever? And why
use this system? I've always used the plain value of the resistance: 10,
56, 5.6K, 56K, etc. Simple, obvious, requires no interpretation. Is this
some kind of Euro thing?

I prefer the nKm to n.mK, as in the second case the very small "." makes
the difference between 5.6 and 56.

Falk

 

[William Sommerwerck]

I agree mit Herr Nebenzahl.

I grew up with Popular Electronics, and it and its sister magazine,
Electronics World, had the nicest-looking schematics I've ever seen,
anywhere. Obviously that's a matter of taste, but they were clean and
handsome (to me).

 

[David Nebenzahl]

On 6/18/2010 1:32 PM Falk Willberg spake thus:

Am 18.06.2010 22:18, schrieb David Nebenzahl:

Someone else made a comment in another thread here about weird
schematics (like for home appliances).

Wanted to get a small discussion going on that topic. My take: there are
good and bad standards for schematics. Personally, I can't stand the
ones that use rectangle shapes for resistors, instead of the traditional
zigzag that [insert name of deity here] intended to be used...

I prefer the traditional (German?) rectangle shape for resistors, your
zigzag things too much look like inductors, Herr Nebenzahl ;-)

Danke schoen, Herr Falk. (ich bin nein ein Deutschlander)

So those little boxes are a German thing, eh?

Well, you should see my on resistor symbols (zigzags). You'd *never*
mistake one of them for an inductor.


--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

 

[N_Cook]

David Nebenzahl <nobody@but.us.chickens> wrote in message
news:4c1bd34c$0$2542$822641b3@news.adtechcomputers.com...

Someone else made a comment in another thread here about weird
schematics (like for home appliances).

Wanted to get a small discussion going on that topic. My take: there are
good and bad standards for schematics. Personally, I can't stand the
ones that use rectangle shapes for resistors, instead of the traditional
zigzag that [insert name of deity here] intended to be used. (And even
here there are lots of variations, like old-fashioned schematics that
took this symbol rather literally and sometimes had ten or twelve zigs
and zags, as if an actual resistor was being constructed on paper).

Likewise the wire-connecting/jumping convention: here I much prefer the
modern approach, which is to use a dot for a connection and no dot for
no connection, rather than the clumsy "loop" to indicate one wire
jumping over another with no connection.

Regarding resistor values: Who the hell came up with that new way of
specifying resistance values, like "10R" "or 5K6" or whatever? And why
use this system? I've always used the plain value of the resistance: 10,
56, 5.6K, 56K, etc. Simple, obvious, requires no interpretation. Is this
some kind of Euro thing?

In general, some schematics just look and feel nicer than others. A
well-drawn schematic is a pleasure to read. A bad one--lines too thin or
too thick, misshapen symbols, idiosyncratic interpretations, etc., just
don't look right.

Feel free to add your own schematic pet peeves here.


--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

How often have you come across compressed pdf-type schema or reduced
paper-based ones where the decimal point has disappeared , and there is no
kerning for dots, so you cannot infer a position for any dot position.
Replace R/K/M for the dot makes a lot of sense.

 

[Arfa Daily]

"N_Cook" <diverse@tcp.co.uk> wrote in message
news:hvhv1s$88b$1@news.eternal-september.org...

David Nebenzahl <nobody@but.us.chickens> wrote in message
news:4c1bd34c$0$2542$822641b3@news.adtechcomputers.com...
Someone else made a comment in another thread here about weird
schematics (like for home appliances).

Wanted to get a small discussion going on that topic. My take: there are
good and bad standards for schematics. Personally, I can't stand the
ones that use rectangle shapes for resistors, instead of the traditional
zigzag that [insert name of deity here] intended to be used. (And even
here there are lots of variations, like old-fashioned schematics that
took this symbol rather literally and sometimes had ten or twelve zigs
and zags, as if an actual resistor was being constructed on paper).

Likewise the wire-connecting/jumping convention: here I much prefer the
modern approach, which is to use a dot for a connection and no dot for
no connection, rather than the clumsy "loop" to indicate one wire
jumping over another with no connection.

Regarding resistor values: Who the hell came up with that new way of
specifying resistance values, like "10R" "or 5K6" or whatever? And why
use this system? I've always used the plain value of the resistance: 10,
56, 5.6K, 56K, etc. Simple, obvious, requires no interpretation. Is this
some kind of Euro thing?

In general, some schematics just look and feel nicer than others. A
well-drawn schematic is a pleasure to read. A bad one--lines too thin or
too thick, misshapen symbols, idiosyncratic interpretations, etc., just
don't look right.

Feel free to add your own schematic pet peeves here.


--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)



How often have you come across compressed pdf-type schema or reduced
paper-based ones where the decimal point has disappeared , and there is no
kerning for dots, so you cannot infer a position for any dot position.
Replace R/K/M for the dot makes a lot of sense.

Yes, I'd go along with that. It is a far more sensible way of showing
values, and I can't see anything counter intuitive about understanding it. I
still prefer zig-zags for resistors, and if I'm drawing a quick 'sketch' of
a diagram, I always still 'jump' the non-connected lines. However, when I'm
hand-drawing a diagram properly, with nice straight lines and 'gridded'
components, I always break one of the two crossing lines, where they break,
so sort of the 'jumping over' convention, but without the actual bridge
being drawn. I'm not sure where I first saw this, but schematics drawn like
it, look quite nice. There's no question about whether lines do connect or
not, and the brain fills in the little missing bit of the line without you
having to think about it. Where lines do connect, they get a nice dot on
them.

I always still use the original logic symbols for gates and counters and
latches and inverters and so on. I find the new style 'blocky' symbols need
too much looking at, and taking into consideration of additional writing and
symbols within the block. I always thought that the original symbols were
all sufficiently different for the most part, to allow instant understanding
of function by quick glance alone.

I would agree that appliance schematics are often unclear, and use odd
symbols. Also, with apologies to Herr Willberg, I think that German
schematics from 20 or 30 years back, are some of the worst to follow that
I've ever seen. I defy anyone who's not German, to follow a Grundig
schematic, for instance ...

Although Dutch, some of Philips' ones from a few years back were also a
nightmare to follow. They had a very frustrating convention regarding where
signals went when they (frequently) disappeared off the side of a page, and
the signal was often nigh on impossible to ever find again ...

But the prize for impossible to follow schematics, has to go to the
automotive industry. Those diagrams have a convention all of their own, and
always have done. Some of the most frustrating fault-tracing sessions of my
life, have involved cars and the electrical diagrams for them. They are a
cross between a schematic and a wiring diagram, with symbols peculiar to and
only understood by automotive manufacturing initiates. Every bullet and
connector is shown, using a variety of different conventions between
manufacturers. Schematics go across multiple pages, with wires that leave
often almost impossible to re-find on the next diagram. Colours, wire gauges
and goodness only knows what other info, are all crammed onto the diagrams.
Nightmare ...

Arfa

 

[N_Cook]

Arfa Daily <arfa.daily@ntlworld.com> wrote in message
news:TP%Sn.34795$Ha1.13804@hurricane...

"N_Cook" <diverse@tcp.co.uk> wrote in message
news:hvhv1s$88b$1@news.eternal-september.org...
David Nebenzahl <nobody@but.us.chickens> wrote in message
news:4c1bd34c$0$2542$822641b3@news.adtechcomputers.com...

Yes, I'd go along with that. It is a far more sensible way of showing
values, and I can't see anything counter intuitive about understanding it.
I
still prefer zig-zags for resistors, and if I'm drawing a quick 'sketch'
of
a diagram, I always still 'jump' the non-connected lines. However, when
I'm
hand-drawing a diagram properly, with nice straight lines and 'gridded'
components, I always break one of the two crossing lines, where they
break,
so sort of the 'jumping over' convention, but without the actual bridge
being drawn. I'm not sure where I first saw this, but schematics drawn
like
it, look quite nice. There's no question about whether lines do connect or
not, and the brain fills in the little missing bit of the line without you
having to think about it. Where lines do connect, they get a nice dot on
them.

I always still use the original logic symbols for gates and counters and
latches and inverters and so on. I find the new style 'blocky' symbols
need
too much looking at, and taking into consideration of additional writing
and
symbols within the block. I always thought that the original symbols were
all sufficiently different for the most part, to allow instant
understanding
of function by quick glance alone.

I would agree that appliance schematics are often unclear, and use odd
symbols. Also, with apologies to Herr Willberg, I think that German
schematics from 20 or 30 years back, are some of the worst to follow that
I've ever seen. I defy anyone who's not German, to follow a Grundig
schematic, for instance ...

Although Dutch, some of Philips' ones from a few years back were also a
nightmare to follow. They had a very frustrating convention regarding
where
signals went when they (frequently) disappeared off the side of a page,
and
the signal was often nigh on impossible to ever find again ...

But the prize for impossible to follow schematics, has to go to the
automotive industry. Those diagrams have a convention all of their own,
and
always have done. Some of the most frustrating fault-tracing sessions of
my
life, have involved cars and the electrical diagrams for them. They are a
cross between a schematic and a wiring diagram, with symbols peculiar to
and
only understood by automotive manufacturing initiates. Every bullet and
connector is shown, using a variety of different conventions between
manufacturers. Schematics go across multiple pages, with wires that leave
often almost impossible to re-find on the next diagram. Colours, wire
gauges
and goodness only knows what other info, are all crammed onto the
diagrams.
Nightmare ...

Arfa

My beef is with caps marked 270 say, is it 27 or 270 ?, if there are no
other same series caps on the board for convention comparison, eg 471

 

[Phil Allison]

"Falk Willberg"

I prefer the traditional (German?) rectangle shape for resistors, your
zigzag things too much look like inductors, Herr Nebenzahl ;-)

** Little boxes, little boxes and they're all made out of ticky tacky .....

Must be some kind of rabid Nazi obsession to put everything and everyone
into boxes ???

With or without Zyklon B gas for filler.

I prefer the nKm to n.mK, as in the second case the very small "." makes
the difference between 5.6 and 56.

** Lotsa folk fail to see the * point * of this .....

Falk

** Must be one of them WW2 Messerschmitt pilots



..... Phil

 

[Michael A. Terrell]

Arfa Daily wrote:

"N_Cook" <diverse@tcp.co.uk> wrote in message
news:hvhv1s$88b$1@news.eternal-september.org...
David Nebenzahl <nobody@but.us.chickens> wrote in message
news:4c1bd34c$0$2542$822641b3@news.adtechcomputers.com...
Someone else made a comment in another thread here about weird
schematics (like for home appliances).

Wanted to get a small discussion going on that topic. My take: there are
good and bad standards for schematics. Personally, I can't stand the
ones that use rectangle shapes for resistors, instead of the traditional
zigzag that [insert name of deity here] intended to be used. (And even
here there are lots of variations, like old-fashioned schematics that
took this symbol rather literally and sometimes had ten or twelve zigs
and zags, as if an actual resistor was being constructed on paper).

Likewise the wire-connecting/jumping convention: here I much prefer the
modern approach, which is to use a dot for a connection and no dot for
no connection, rather than the clumsy "loop" to indicate one wire
jumping over another with no connection.

Regarding resistor values: Who the hell came up with that new way of
specifying resistance values, like "10R" "or 5K6" or whatever? And why
use this system? I've always used the plain value of the resistance: 10,
56, 5.6K, 56K, etc. Simple, obvious, requires no interpretation. Is this
some kind of Euro thing?

In general, some schematics just look and feel nicer than others. A
well-drawn schematic is a pleasure to read. A bad one--lines too thin or
too thick, misshapen symbols, idiosyncratic interpretations, etc., just
don't look right.

Feel free to add your own schematic pet peeves here.


--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)



How often have you come across compressed pdf-type schema or reduced
paper-based ones where the decimal point has disappeared , and there is no
kerning for dots, so you cannot infer a position for any dot position.
Replace R/K/M for the dot makes a lot of sense.


Yes, I'd go along with that. It is a far more sensible way of showing
values, and I can't see anything counter intuitive about understanding it. I
still prefer zig-zags for resistors, and if I'm drawing a quick 'sketch' of
a diagram, I always still 'jump' the non-connected lines. However, when I'm
hand-drawing a diagram properly, with nice straight lines and 'gridded'
components, I always break one of the two crossing lines, where they break,
so sort of the 'jumping over' convention, but without the actual bridge
being drawn. I'm not sure where I first saw this, but schematics drawn like
it, look quite nice. There's no question about whether lines do connect or
not, and the brain fills in the little missing bit of the line without you
having to think about it. Where lines do connect, they get a nice dot on
them.

I always still use the original logic symbols for gates and counters and
latches and inverters and so on. I find the new style 'blocky' symbols need
too much looking at, and taking into consideration of additional writing and
symbols within the block. I always thought that the original symbols were
all sufficiently different for the most part, to allow instant understanding
of function by quick glance alone.

I would agree that appliance schematics are often unclear, and use odd
symbols. Also, with apologies to Herr Willberg, I think that German
schematics from 20 or 30 years back, are some of the worst to follow that
I've ever seen. I defy anyone who's not German, to follow a Grundig
schematic, for instance ...

Although Dutch, some of Philips' ones from a few years back were also a
nightmare to follow. They had a very frustrating convention regarding where
signals went when they (frequently) disappeared off the side of a page, and
the signal was often nigh on impossible to ever find again ...

But the prize for impossible to follow schematics, has to go to the
automotive industry. Those diagrams have a convention all of their own, and
always have done. Some of the most frustrating fault-tracing sessions of my
life, have involved cars and the electrical diagrams for them. They are a
cross between a schematic and a wiring diagram, with symbols peculiar to and
only understood by automotive manufacturing initiates. Every bullet and
connector is shown, using a variety of different conventions between
manufacturers. Schematics go across multiple pages, with wires that leave
often almost impossible to re-find on the next diagram. Colours, wire gauges
and goodness only knows what other info, are all crammed onto the diagrams.
Nightmare ...

You should see some old IBM mainframe schmatics. Almost everything
is a box.


--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.

 

[Adrian Tuddenham]

Arfa Daily <arfa.daily@ntlworld.com> wrote:

[...]

But the prize for impossible to follow schematics, has to go to the
automotive industry. Those diagrams have a convention all of their own, and
always have done.

Some years ago I owned a Standard Vanguard and the circuit diagram in
the owners handbook (you didn't need to buy an expensive workshop
manual) was exemplary. I have never seen one as clear as that for any
other car.


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

 

[Adrian Tuddenham]

David Nebenzahl <nobody@but.us.chickens> wrote:

Someone else made a comment in another thread here about weird
schematics (like for home appliances).

[...]
... wire-connecting/jumping convention: here I much prefer the
modern approach, which is to use a dot for a connection and no dot for
no connection, rather than the clumsy "loop" to indicate one wire
jumping over another with no connection.

I find the 'gap' convention is easy to draw (with a computer) and
extremely easy to read. It also looks tidy. Four-way junctions which
could be mistaken for crossings should never be used, they should be
staggered instead.

e.g.
http://www.poppyrecords.co.uk/compton/images/BassAmplifier.gif

Regarding resistor values: Who the hell came up with that new way of
specifying resistance values, like "10R" "or 5K6" or whatever? And why
use this system? I've always used the plain value of the resistance: 10,
56, 5.6K, 56K, etc. Simple, obvious, requires no interpretation. Is this
some kind of Euro thing?

I first saw it in German and Dutch publications. Once you have become
accustomed to it, it is quite easy to use and it is utterly unambiguous,
even when badly photocopied.


Probably the best circuit diagrams were those in Wireless World when it
was still part of Illiffe Publications (also those in BBC Technical
Instructions). They were drawn by trained draughtsmen who also
understood electronics.

The worst ones are those with boxes. A symbol should indicate what the
component is without having to read the small print. I was very pleased
when Wireless World declared that it would not be following British
Standards and would continue to use 'proper' symbvols.


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

 

[Falk Willberg]

Am 19.06.2010 15:59, schrieb Phil Allison:

"Falk Willberg"

I prefer the traditional (German?) rectangle shape for resistors, your
zigzag things too much look like inductors, Herr Nebenzahl ;-)

....

Must be some kind of rabid Nazi obsession to put everything and everyone
into boxes ???

With or without Zyklon B gas for filler.

By the way, when you have stopped to slaughter aborigines? Before or
after WWII?

Falk

 

[David Nebenzahl]

On 6/19/2010 8:35 AM Adrian Tuddenham spake thus:

David Nebenzahl <nobody@but.us.chickens> wrote:

Someone else made a comment in another thread here about weird
schematics (like for home appliances).

[...]
... wire-connecting/jumping convention: here I much prefer the
modern approach, which is to use a dot for a connection and no dot for
no connection, rather than the clumsy "loop" to indicate one wire
jumping over another with no connection.

I find the 'gap' convention is easy to draw (with a computer) and
extremely easy to read. It also looks tidy. Four-way junctions which
could be mistaken for crossings should never be used, they should be
staggered instead.

e.g.
http://www.poppyrecords.co.uk/compton/images/BassAmplifier.gif

BZZZZZZT! Fail.

While the gap thing looks OK for non-crossing wires, I have to ding the
drafts-person of that schematic for the following:

o Idiosyncratic symbols for electrolytic cazapitors[1]
o Idiosyncratic ground symbol (one horizontal line????)
o And no, I disagree about those offsets for connecting wires.

That's totally unnecessary here: it would be quite obvious that all
those vertical wires connect to what is obviously a bus or rail. A
well-drawn dot is all that's needed there.

(And I don't much like their transistor symbols either)


[1] With apologies to J. Liebermann.


--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

 

[Adrian Tuddenham]

David Nebenzahl <nobody@but.us.chickens> wrote:

On 6/19/2010 8:35 AM Adrian Tuddenham spake thus:

David Nebenzahl <nobody@but.us.chickens> wrote:

Someone else made a comment in another thread here about weird
schematics (like for home appliances).

[...]
... wire-connecting/jumping convention: here I much prefer the
modern approach, which is to use a dot for a connection and no dot for
no connection, rather than the clumsy "loop" to indicate one wire
jumping over another with no connection.

I find the 'gap' convention is easy to draw (with a computer) and
extremely easy to read. It also looks tidy. Four-way junctions which
could be mistaken for crossings should never be used, they should be
staggered instead.

e.g.
http://www.poppyrecords.co.uk/compton/images/BassAmplifier.gif

BZZZZZZT! Fail.

While the gap thing looks OK for non-crossing wires, I have to ding the
drafts-person of that schematic for the following:

o Idiosyncratic symbols for electrolytic cazapitors...

It appears that you had no difficulty identifying them, so they
succeeded as symbols. The polarity is also a lot more 'intuitive' than
the conventional symbol.

o Idiosyncratic ground symbol (one horizontal line????)

Again, you recognised it without ambiguity and it isn't all that
unusual:
<http://www.ortodoxism.ro/datasheets2/a/0scgel8exqr094jlw9qfjx9qjc3y.pdf

o And no, I disagree about those offsets for connecting wires.

That's totally unnecessary here: it would be quite obvious that all
those vertical wires connect to what is obviously a bus or rail. A
well-drawn dot is all that's needed there.

That's your preference, but I prefer offsets because they are utterly
unambiguous, even in a poorly copied drawing.

(And I don't much like their transistor symbols either)

For junction transistors they are incorrect, I agree, but I have become
used to them. I find it takes me a while to get my mind around the
correct symbols because they are so rarely used nowadays

Just for fun, I've replaced the point-contact symbols in that drawing
with the correct junction ones:

http://www.poppyrecords.co.uk/compton/images/BassAmplifier2.gif

The wrong symbols have become so well-estabilshed nowadays that I doubt
if most people even noticed they were wrong.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

 

[David Nebenzahl]

On 6/19/2010 1:19 PM Adrian Tuddenham spake thus:

David Nebenzahl <nobody@but.us.chickens> wrote:

(And I don't much like their transistor symbols either)

For junction transistors they are incorrect, I agree, but I have become
used to them. I find it takes me a while to get my mind around the
correct symbols because they are so rarely used nowadays

Just for fun, I've replaced the point-contact symbols in that drawing
with the correct junction ones:

http://www.poppyrecords.co.uk/compton/images/BassAmplifier2.gif

The wrong symbols have become so well-estabilshed nowadays that I doubt
if most people even noticed they were wrong.

Now that's just plain *weird*.

Since when are the *conventional* symbols for (junction) transistors
considered to be for the old, obsolete point-contact ones? Every single
schematic that uses transistors--modern silicon ones, not ancient
point-contact germanium ones--uses the conventional symbols, like the
ones in the first drawing you posted.

I've *never* seen symbols like the ones in your "new, improved" drawing.
Those are just plain idiosyncratic, non-standard and weird. They look
kind of like diodes with an elongated anode.

I'll stick with the tried and true standard symbols, thank you very much.


--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

 

[Adrian Tuddenham]

David Nebenzahl <nobody@but.us.chickens> wrote:

On 6/19/2010 1:19 PM Adrian Tuddenham spake thus:

David Nebenzahl <nobody@but.us.chickens> wrote:

(And I don't much like their transistor symbols either)

For junction transistors they are incorrect, I agree, but I have become
used to them. I find it takes me a while to get my mind around the
correct symbols because they are so rarely used nowadays

Just for fun, I've replaced the point-contact symbols in that drawing
with the correct junction ones:

http://www.poppyrecords.co.uk/compton/images/BassAmplifier2.gif

The wrong symbols have become so well-estabilshed nowadays that I doubt
if most people even noticed they were wrong.

Now that's just plain *weird*.

I thought you would find them interesting.

Since when are the *conventional* symbols for (junction) transistors
considered to be for the old, obsolete point-contact ones?

When junction transistors were first introduced there was a need for a
new symbol to distinguish them from the point-contact type which the
'conventional' symbol represented. Several eminent journals and text
books changed over to the new 'junction' symbol, but, by then, the
point-contact symbol was so well established that the change never
caught on.

Every single
schematic that uses transistors--modern silicon ones, not ancient
point-contact germanium ones--uses the conventional symbols, like the
ones in the first drawing you posted.

You will find the 'junction' symbols in some Acoustical Quad circuit
diagrams, Peter Walker was a stickler for getting things right. They
also appeared in Wireless World for a while and are used in "The
Foundations of Wireless" by M.G. Scroggie (8th Edition) specifically to
distinguish the two different types of transistor.

I've *never* seen symbols like the ones in your "new, improved" drawing.
Those are just plain idiosyncratic, non-standard and weird. They look
kind of like diodes with an elongated anode.

They certainly look strange when you have been used to the
point-contact symbol, but you must admit they give a clear
representation of a junction transistor.

I'll stick with the tried and true standard symbols, thank you very much.

At least you will be able to recognise the other types if you ever
encounter them again.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

 

On Fri, 18 Jun 2010 13:18:41 -0700, David Nebenzahl
<nobody@but.us.chickens> wrote:

Someone else made a comment in another thread here about weird
schematics (like for home appliances).

Wanted to get a small discussion going on that topic. My take: there are
good and bad standards for schematics. Personally, I can't stand the
ones that use rectangle shapes for resistors, instead of the traditional
zigzag that [insert name of deity here] intended to be used. (And even
here there are lots of variations, like old-fashioned schematics that
took this symbol rather literally and sometimes had ten or twelve zigs
and zags, as if an actual resistor was being constructed on paper).

Likewise the wire-connecting/jumping convention: here I much prefer the
modern approach, which is to use a dot for a connection and no dot for
no connection, rather than the clumsy "loop" to indicate one wire
jumping over another with no connection.

Regarding resistor values: Who the hell came up with that new way of
specifying resistance values, like "10R" "or 5K6" or whatever? And why
use this system? I've always used the plain value of the resistance: 10,
56, 5.6K, 56K, etc. Simple, obvious, requires no interpretation. Is this
some kind of Euro thing?

In general, some schematics just look and feel nicer than others. A
well-drawn schematic is a pleasure to read. A bad one--lines too thin or
too thick, misshapen symbols, idiosyncratic interpretations, etc., just
don't look right.

Feel free to add your own schematic pet peeves here.
Well, the worst schematics of all are those which you cannot find.

Even the most miserable scratching on a crumpled piece of paper is
better.

While I learned using the 3.3K style, I fiend the 3K3 eminently
satisfactory, especially because of the redundancy. As was
mentioned,, this is important when dealing with a PDF of a poorly
scanned, poorly printed original.

I prefer the 'old' style - zig-zag lines for resistors, parallel lines
for non-polar capacitors, etc.

Lines should be drawn with the little loop when crossing lines do not
connect, a dot when they do. Again, redundancy.

Tags indicating the signal connecting to an IC should have an arrow
indicating if the signal is an input or an output, double arrows for a
bidirectional bus. And when a signal goes off the page, the
description should be accompanied by the page and grid location of the
destination, as in < SYNC 3E5 indicating the SYNC signal is coming
from page 3, grid location E5.

As a bonus, the location of each component should be tabulated,
either on the schematic, or in a separate chart so it is possible to
determine that IC205 is on the bottom side of the circuit board at
grid location J12.

PlainBill

 

[Rich Webb]

On Sat, 19 Jun 2010 15:29:45 -0700, PlainBill47@yahoo.com wrote:

Lines should be drawn with the little loop when crossing lines do not
connect, a dot when they do. Again, redundancy.

Crossings (four-way intersections) never connect. Three-way
intersections always connect. Stick with that convention and neither the
humpie or a dot are needed, although dots do "look right."

There is an authorized reprint of H&H's "How to Draw Schematic Diagrams"
from AoE Appx E over at
http://opencircuitdesign.com/xcircuit/goodschem/goodschem.html

--
Rich Webb Norfolk, VA

 

[Arfa Daily]

"David Nebenzahl" <nobody@but.us.chickens> wrote in message
news:4c1d00fe$0$2388$822641b3@news.adtechcomputers.com...

On 6/19/2010 8:35 AM Adrian Tuddenham spake thus:

David Nebenzahl <nobody@but.us.chickens> wrote:

Someone else made a comment in another thread here about weird
schematics (like for home appliances).

[...]
... wire-connecting/jumping convention: here I much prefer the modern
approach, which is to use a dot for a connection and no dot for
no connection, rather than the clumsy "loop" to indicate one wire
jumping over another with no connection.

I find the 'gap' convention is easy to draw (with a computer) and
extremely easy to read. It also looks tidy. Four-way junctions which
could be mistaken for crossings should never be used, they should be
staggered instead.

e.g.
http://www.poppyrecords.co.uk/compton/images/BassAmplifier.gif

BZZZZZZT! Fail.

While the gap thing looks OK for non-crossing wires, I have to ding the
drafts-person of that schematic for the following:

o Idiosyncratic symbols for electrolytic cazapitors[1]
o Idiosyncratic ground symbol (one horizontal line????)
o And no, I disagree about those offsets for connecting wires.

That's totally unnecessary here: it would be quite obvious that all those
vertical wires connect to what is obviously a bus or rail. A well-drawn
dot is all that's needed there.

(And I don't much like their transistor symbols either)


[1] With apologies to J. Liebermann.

I must say that I don't really like the staggered connections, but what's
wrong with the transistor symbols ? And the single heavy horizontal line for
the 0v rail, is very common this side of the pond. 0v rails always used to
be shown as a heavy horizontal line right across the schematic, sometimes
with a chassis symbol attached as well. These days, most schematics are so
complex, that the 0v line is now left out, and 'abbreviated' to individual
short heavy lines at each connection point on the schematic. The
electrolytic symbol is not, however, the one commonly used here, which is a
pair of rectangles, one filled in for the -ve side, and the other open for
the +ve side. Sometimes, the American convention of one straight and one
curved plate, is used.

Arfa

 

[Cydrome Leader]

David Nebenzahl <nobody@but.us.chickens> wrote:

Someone else made a comment in another thread here about weird
schematics (like for home appliances).

Wanted to get a small discussion going on that topic. My take: there are
good and bad standards for schematics. Personally, I can't stand the
ones that use rectangle shapes for resistors, instead of the traditional

I find rectangles obnoxious, unless somebody from europe is drawing
something in front of me.

intended to be used. (And even
here there are lots of variations, like old-fashioned schematics that
took this symbol rather literally and sometimes had ten or twelve zigs
and zags, as if an actual resistor was being constructed on paper).

Likewise the wire-connecting/jumping convention: here I much prefer the
modern approach, which is to use a dot for a connection and no dot for
no connection, rather than the clumsy "loop" to indicate one wire
jumping over another with no connection.

I was taught the half-loop shape first, then moved to the dots and no
dots. It seemed like how you're taught to ties shoes in a really complex
method of making two rabbit ears first, then tying them.

Regarding resistor values: Who the hell came up with that new way of
specifying resistance values, like "10R" "or 5K6" or whatever? And why
use this system? I've always used the plain value of the resistance: 10,
56, 5.6K, 56K, etc. Simple, obvious, requires no interpretation. Is this
some kind of Euro thing?

I first saw that on this newsgroup. My question is what idiots came up
with it and why?