18 May
2009
18 May
'09
4:28 p.m.
On May 16, 2009, at 8:47 PM, Chuck Guzis wrote:
I'm not a telephony geek, but this comment prompted me to go look
at that schematic. That's a really neat little circuit. What are
the four odd components? The symbols sorta look like DIACs.
-Dave
--
Dave McGuire
Port Charlotte, FL
... and the
schematic...
http://www.porticus.org/bell/images/35_dial.gif
One of my favorite schematics! Generating DTMF with a single
transistor. ISTR that the 113 modem was equally sparse in active
devices, but I can't find a schematic anywhere. 