I changed the original design to have P1 on the master PCB only since familiar persons will operate the device. The slave has two fixed value resistors (R10 and R11) to set the volume.
Turning the volume pot all the way down there won't be anything audible.
here are the circuits you 1st and 2nd time you sent for me , i want to ask why got 2 more extra connection , that mean i need shielded 6-wire cable ....?
The intercom will feed all kinds of nasty noises from outdoors into the home.
Dogs barking, cats fighting, motorcycles, trucks and jet airplanes.
I think it should be turned off when it is not being used and be turned on by the person outdoors pressing the doorbell button. Then the master can turn it off when the communication is finished.
The intercom will feed all kinds of nasty noises from outdoors into the home.
Dogs barking, cats fighting, motorcycles, trucks and jet airplanes.
I think it should be turned off when it is not being used and be turned on by the person outdoors pressing the doorbell button. Then the master can turn it off when the communication is finished.
The circuit I suggested doesn't have a POWER ON/OFF switch. Without a POWER ON/OFF switch you'll have the advantage of listening to outdoor voices. Just your own voice won't be heard when the switch is in the "SILENT" position.
A cable with an RCA plug on each end is used for each channel of audio from a TV to an amplifier and the cable is shielded. But it might be too short for an intercom.