2 Aug
2005
2 Aug
'05
2:10 p.m.
On 8/2/05, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
Having a) looked at competitors features, and b) built similar
products myself, the ones for sale are not simple. Ours used a pair
of SLICs (Subscriber Line ICs) just as a proper PBX or Telco switch
port would use. In between a few sq in. of through-hole passives, we
had an 8048-type microcontroller generating dial tones, interpreting
telephone numbers, triggering ring voltages, etc. Ours, being two
lines, fit in a standard Pac-Tec box that was about 6" x 6" x 2" and
was *covered* in parts. SMT could have made it cheaper, but it was
designed in a non-modern environment for low-volume production. We
didn't make enough to fill a shopping cart.
-ethan
...essentially simulates a telephone
network.... sold by Black Box.
I am surprised, but I have never seen a published schematic for such a
unit, neither in a magaxine or on the web. They can't be _that_
complicated, surely?