Arfa Daily wrote:


"N_Cook" wrote in message
...
David Nebenzahl wrote in message
.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

ha, plus every damn wire is taped together into some completely awful
harness. There has to be at least 50 pounds of PVC electrical tape in
every car out there.