Re: gEDA-user: wrong pinout lm7912 symbol

[Wojciech Kazubski <wk0@xxxxx>]

> On Tue, 2007-09-11 at 13:59 -0400, Ales Hvezda wrote:
> > >
> > > If someone thinks the attached symbol is ok, I'm pushing it to the repo.
> > >
> > 
> > How do you know that this pinout is correct?  What other packages does
> > an lm7912 come in other than TO-220?  There isn't a footprint=
> > attribute in the original symbol.  My concern is breaking existing
> > user schematics.
> > 
> > -Ales
> ... They used to be available in TO-3, didn't they?
> -- 
> Greg
> 
Yes, but with a bit different numbering scheme. Usually the pins in TO3 LM/uA7800 are numbered in the following way:
transistor BASE ----> pin 1 ---> INPUT
transistor EMITTER ----> pin 2 ----> OUTPUT
transistot COLLECTOR ----> pin 3 ----> GND

This is different than in TO220.
Some manufacturers does not use pin numbers but only pin names.

The TO3 in PCB m4 library has a bug, pins 1 and 2 are swapped so EMITTER is pin 1 and BASE is pin 2.

Shall we correct this?

There are also LM78Lxx that comes in TO92 (most popular), TO39, SO8, SOT89 ... , each with different pinning!



Wojciech


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