gEDA-user: 2N3906 gschem & pcb

Wojciech Kazubski wk at ire.pw.edu.pl
Mon Jul 10 11:41:19 EDT 2006


> I think there is a difference in pin assignments on the 2N3906
> parts between GSCHEM and PCB.
>
>                        E   B    C
>     PCB            1    2    3
>     GSCHEM    3    2    1
>
> I am not very good at transistors and the resultant circuit
> has some strange behavior (not all bad). I notice that some
> transistors in gschem use the EBC notation while others
> use 123 or 321.
>
> George

There are two methods of numbering pins in TO92. One is prefered in Europe, 
while the second one is used in US. 
Compare a datasheet of BC547 from Philips and for example TL431 from 
Fairchild:
http://noel.feld.cvut.cz/semi/philips/acrobat/7641.pdf
http://www.fairchildsemi.com/ds/TL/TL431A.pdf
So both programs are correct but to diffeent standards :-(

Wojciech Kazubski


More information about the geda-user mailing list