shown in Figure
my PBX can pulse-dial and ring the
It can connect
to an outside line
by dialing 9, then
dial up any
number in the
world, including cell phones. Plus, I used the Arduino
Mega to add a six-number auto-dial memory function
much like modern phones.
Finally, it has a secret “Spirit of the Telephone” hidden
inside the circuitry that randomly replays Alexander
Graham Bell’s first call in 1876, and a comedic routine by
our favorite TV operator, Lily Tomlin.
I’m not alone in my fascination with old telephones.
There are two major groups — Antique Telephone
Collectors Association (ATCA) and Telephone Collectors
International (TCI) — whose members have constructed
much more elaborate (by a factor of 100) step-by-step
switching systems in their garages and basements. These
folks are really serious about vintage telephones and
Hopefully, other innovative experimenters will find
applications for these funky displays and devise alternate
schemes to drive groups of them, which may cut down on
the number of components.
In the meantime, just remember, steampunk rules!
■ FIGURE 10.
The back of the
relays, and a blue
Innovative Holding Solutions
NEW PV Jr.
Mini Circuit Board Holder
40 July/August 2018