enrico,
So the circuit: D
+ -----/\/\/\--->|------
R=1K + - |+
Speaker = C=10uF
|-
- ----------------------
I've a little comprehension about this circuit: if the current
occured, it will by-pass the diode (a kind like IN4001?) to deliver
current through (but what R is for?
When I suggested the resistor I was thinking about the speaker having to
handle other sound, which might be distorted with the diode connected. The
resistor might cause a slight delay in the charge on the capacitor. The
effect would depend on what voltage level was required by the device being
controlled.
And if the output signal from speaker is
small, is it enough to make diode pass the current?
This would take some experimentation. The resistor value
could be reduced if necessary, perhaps even removed.
I thought diode has a 0.7V threshold).
I think the output voltage should be greater than 1V.
C will do for storage the signal.
Auto dial will do by a feature from our Telcomm (Hotline delay), i.e.
when we pick up the phone and hang it for 5 seconds (not dial
anything), it will always automatically call a number that we want.
If you have to do this manually, i.e. no kind of plug in remote control, I
don't see how this feature can be use.
Here's an alternative. Most computers have the ability to dial
telephones through the computer modem...
I don't have any modems, I think it's a good solution (just like d
nixon advice) but expensive, beside, I don't understand about AT
command.
AT commands are not difficult, but it doesn't matter if you can't afford a
modem.
Jim
