The circuit is really quire useless.
It only rings in one direction and you don't actually ring the other phone. The "ringer" is a piezo and it is "connected" to the "exchange."
In addition, why use a 20 pin PIC chip and crystal when an 8-pin will do the job?
I think everyone who has read this post has not done any homework.
I have designed lots of phone systems and this one is totally useless.
Phones don't work on 6v. They need 8-10v minimum for any volume to be produced.
The phone described as central should be described as subscriber as the subscriber gets rung and the electronics go with the subscriber.
For what it does, you only need 2 phones, a switch and an electronic buzzer. It is grossly over-designed.
It only rings in one direction and you don't actually ring the other phone. The "ringer" is a piezo and it is "connected" to the "exchange."
In addition, why use a 20 pin PIC chip and crystal when an 8-pin will do the job?
I think everyone who has read this post has not done any homework.
I have designed lots of phone systems and this one is totally useless.
Phones don't work on 6v. They need 8-10v minimum for any volume to be produced.
The phone described as central should be described as subscriber as the subscriber gets rung and the electronics go with the subscriber.
For what it does, you only need 2 phones, a switch and an electronic buzzer. It is grossly over-designed.
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