"N_Cook" wrote in message
...
William Sommerwerck wrote in message
...
What does the symbol mean with 2 barbs to the bar...?

It's supposed to look something like the letter Z -- hence, a Zener
diode.



That is logical and my experience too but not in this case , hence the
query.
One barb represents zeners in the symbol set used on this schematic, so
what
does the 2 barb (normally zener) symbol mean here?

The various typefaces used by the many people who produce schematics add to
the confusion and some use (often inaccurate) variations of the standard
symbols making matters even worse.

There are of course yet more different types of diode, some of which also
have their own symbol (and variants).

As to answer your original question, it would be hard to improve on the
links JW posted.