phone dialer

Thread Starter

R!f@@

Joined Apr 2, 2009
9,918
I need to make this simple but yet effective. Component is not a problem. I can probably get anything now. :D

All I have is N/O contact from the alarm.
I need to make a circuit to dial a programmed no. when I get the signal. land line phone, dialing no. has +960 XXXXXXX . These are the character amount of our telephone no.s

On activation the circuit needs to pick up the line, wait for dial tone and then dial the no. If bzy, try again. Wait till the party picks up the call and enter acknowledge numbers such as a numeric code like 0000 ( programmable). If entered correct code deactivate further dialing, If hanged without code. Redial again.

So what are ur ideas on this.
 
Last edited:

ErnieM

Joined Apr 24, 2011
8,377
Way way back I did some experiments on POTS phone lines. I vaguely remember using a Radio Shack 1000 ohms to 8 ohm transformer ( 273-1380) to get a cassette to play over the phone line. I believe connecting it caused the line to connect to the central office (ie, pick up). The connection is 1000 ohms -> phone line, 8 ohms -> cassette speaker output.

So anything capable of making the touch tones could play thru a speaker amp to this transformer. You would have to experiment to find a good level. The tones are a mix of two frequencies, there used to be an (Signetics?) IC that could generate these but I dioubt it is still in production.

Radio Shack still sells this item some 40 years since I got my first one.
 
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