RE: gEDA: Type numbers for transistors

["Timmerman, LJH" <bert_dot_timmerman-at-NOSPAMcorusgroup_dot_com>]

Hi Wojciech (and all),

I think that pinning [1, 2, 3] instead of [e, b, c] is not bad in itself as
long as it's consistent (for __all__ transistor symbols, same goes for
diodes BTW with [1, 2] --> [a, k]).

With a text 'e', 'b' and 'c' in visible mode and the pinnumber in invisible
mode things look OK if you print a schematic on a printer or produce a png
file.

For the netlist and PCB things are a bit different.

I could imagine that the 'device=' attribute has something to do with the
behaviour of the component (pnp, npn, connector, header, diode, IC, ...) in
a simulator [spice, acs, ...],
and that a 'devicename=' attribute specifies the type (for instance BC547,
BF240 etc.).

The 'footprint=' attribute could say something about the package (TO92) and
layout of the pins (which __is__ important for PCB).

Now the problem lies in the 'devicename=' attribute, sofar it is a text with
color green and not an attribute in color yellow (this attribute could be
altered of course).

The above is feasable, the only thing to add is the 'devicename=' attribute
and delete the green text (with the devicename) in the symbol.

Just my EUR 0.01.

Kind regards,

Bert Timmerman.

>  -----Original Message-----
> From: 	Wojciech Kazubski <wk@ire.pw.edu.pl>@CORUS  
> Sent:	maandag 25 februari 2002 12:43
> To:	geda-dev@seul.org
> Subject:	gEDA: Type numbers for transistors
> 
>  
> Hi All!
> 
> Few days ago Antonio asked for making device= attribute 
> editable for some
> microcontrollers.
> The same, or even greater, problem exists for discrete 
> devices, especially
> for transistors. There are thousands of devices which share 
> the same symbol,
> but sometimes they have different pining. This is especially 
> true for TO92
> package that has 5 different pinning (of 6 possible) - 
> compare BC548, BF240,
> 2SC1815, 2N3904 for example.
> PCB generally use pin numbers but there is a file 
> (transistor.m4) that seems
> to contain pinning for some, but very few, transistors. I 
> have problem with
> making this working :-(.  The board created by gnetlist -g 
> PCBboard has pins
> "1" "2" and "3" while the netlist created by gnetlist -g PCB 
> has pinnames E,
> B and C.
> 
> There are three solutions:
> 1) Create a special symbol for each device (or even three, based on
> npn-1.sym, npn-2.sym and npn-3.sym). This will take quite 
> much disk space (at
> least  one block 1-4kB for each symbol) and may cause problems with
> mantaining the symbols.
> 2) Make gnetlist use pining definitions from PCB and add more 
> entries there
> (modify PCB`s files?).
> 3) Make symbols like npn-ebc-1.sym, npn-bec-1.sym with 
> pinnumbers instead of
> E, B and C. The user must then know what symbol to use 
> (external database?)
> and the device= attribute must be editable.
> 
> Which is the best?
> 
> Now the device= contains something like NPN_TRANSISTOR and 
> must be overriden
> by a new attribute like device=BC237
> 
> W. Kazubski

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