Re: gEDA-user: lost newbie (lm741 symbol)

[Carlos Nieves Ónega <cnieves@xxxxxxxxxx>]

Hi Marc,
your symbol is technically correct. Some points about it:
  - Attributes like numslots and footprint are usually not pin
attributes. I mean you don't add them to a pin. They are placed as
hidden text in the symbol. Currently you added them as they were
attributes of the pin number 1.
  - Some people don't like "heavy symbols": symbols with attributes like
the footprint attached. They prefer adding them after the schematic is
drawn, as they can use the symbol for other variations of the IC, for
example, a LM741 in SMD package.

Personally, I'd better like an operational amplifier's like symbol for
an operational amplifier, so I can see what it is at first glance... I
noticed you draw the symbol as shown in the National's LM741 datasheet.
In the first page of that datasheet, there is also an example of an
offset nulling circuit. I mean a symbol like that. However, every one
has his own preferences. If you like the symbol as is, it's fine.

Regards,

Carlos


El lun, 09-01-2006 a las 01:53 +0000, Marc escribiÃ:
> This symbol shows no errors now and allows you to attach stuff anyone 
> who cares to try it out let me know if i did it ok
> 
> Marc :)
> documento de texto sencillo adjunto (lm741-2.sym)
> v 20050820 1
> T -475 850 8 8 0 0 0 0 1
> device=LM741
> T 338 1414 9 8 1 0 0 0 1
> LM741
> T 1114 1470 8 10 1 1 0 0 1
> refdes=U?
> P 300 500 0 500 1 0 1
> {
> T 167 606 5 8 1 1 0 0 1
> pinnumber=3
> T 50 519 5 8 0 0 0 0 1
> pinseq=3
> T 200 494 5 10 0 0 0 0 1
> pinlabel=3
> T 200 494 5 10 0 0 0 0 1
> pintype=in
> }
> P 300 100 0 100 1 0 1
> {
> T 150 69 5 8 0 0 270 0 1
> pinseq=4
> T 300 94 5 10 0 0 270 0 1
> pinlabel=4
> T 300 94 5 10 0 0 270 0 1
> pintype=pwr
> T 139 208 5 10 1 1 0 0 1
> pinnumber=4
> }
> P 1300 500 1600 500 1 0 1
> {
> T 1384 619 5 8 1 1 0 0 1
> pinnumber=6
> T 1375 519 5 8 0 0 0 0 1
> pinseq=6
> T 1300 494 5 10 0 0 0 0 1
> pinlabel=6
> T 1300 494 5 10 0 0 0 0 1
> pintype=out
> }
> P 1300 900 1600 900 1 0 1
> {
> T 1375 844 5 8 0 0 270 0 1
> pinseq=7
> T 1300 894 5 10 0 0 270 0 1
> pintype=pwr
> T 1381 1007 5 10 1 1 0 0 1
> pinlabel=7
> T 1300 894 5 10 0 0 0 0 1
> pinnumber=7
> }
> L 300 1400 300 0 3 0 0 0 -1 -1
> L 1300 1400 300 1400 3 0 0 0 -1 -1
> L 1300 0 300 0 3 0 0 0 -1 -1
> P 1300 100 1600 100 1 0 1
> {
> T 1395 222 5 8 1 1 0 0 1
> pinnumber=5
> T 1375 119 5 8 0 0 0 0 1
> pinseq=5
> T 1300 94 5 10 0 0 0 0 1
> pinlabel=5
> T 1300 94 5 10 0 0 0 0 1
> pintype=pas
> }
> P 300 1300 0 1300 1 0 1
> {
> T 226 1247 5 8 0 0 270 2 1
> pinseq=1
> T 301 1297 5 10 0 0 270 2 1
> pintype=pas
> T 249 1402 5 10 1 1 0 6 1
> pinlabel=1
> T 301 1297 5 10 0 0 0 0 1
> numslots=0
> T 301 1297 5 10 0 0 0 0 1
> footprint=DIP8
> T 301 1297 5 10 0 0 0 0 1
> pinnumber=1
> }
> P 1300 1300 1600 1300 1 0 1
> {
> T 1383 1419 5 8 1 1 0 0 1
> pinnumber=8
> T 1575 1319 5 8 0 0 0 0 1
> pinseq=8
> T 1500 1294 5 10 0 0 0 0 1
> pinlabel=8
> T 1500 1294 5 10 0 0 0 0 1
> pintype=pas
> }
> L 1300 1400 1300 0 3 0 0 0 -1 -1
> T 417 386 9 6 1 0 0 0 1
> in +
> T 963 878 9 6 1 0 0 0 1
> Vcc
> P 300 900 0 900 1 0 1
> {
> T 169 1013 5 8 1 1 0 0 1
> pinnumber=2
> T 152 926 5 8 0 0 0 0 1
> pinseq=2
> T 302 901 5 10 0 0 0 0 1
> pinlabel=2
> T 302 901 5 10 0 0 0 0 1
> pintype=in
> }
> T 416 869 9 6 1 0 0 0 1
> in -
> T 419 1090 9 6 1 0 0 0 2
> offset 
> 
> T 421 1159 9 6 1 0 0 0 1
> null
> T 897 24 9 6 1 0 0 0 1
> null
> T 895 -45 9 6 1 0 0 0 2
> offset 
> 
> T 1083 1287 9 6 1 0 0 0 1
> nc
> T 884 463 9 6 1 0 0 0 1
> output
> T 423 80 9 6 1 0 0 0 1
> Vee
-- 
Carlos Nieves Ãnega <cnieves@xxxxxxxxxx>