KamalS
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telephone ringer
I want to ring my POTS telephone line in house.
Here is what I want to do:
I have a number of telephones connected in parallel to the main telephone line.
If I can superimpose the ringer tone required onto the main telephone line (it carries 120V when idle), I can make all the phones ring - an elementary intercom - but powered completely from the main telephone line.
NOTE : I do not need to generate 120V as that is already present on the main telephone line - I need to "somehow" impose the ringing signal (connect the ringer via a cap or high valued resistor or diode or all of these?).
A simple ringer that can be powered from the main telephone line without loading it too would be appreciated (maybe a 5V1 zener across a 555 timer or something)
Any ideas/suggestions/working circuits?
I want to ring my POTS telephone line in house.
Here is what I want to do:
I have a number of telephones connected in parallel to the main telephone line.
If I can superimpose the ringer tone required onto the main telephone line (it carries 120V when idle), I can make all the phones ring - an elementary intercom - but powered completely from the main telephone line.
NOTE : I do not need to generate 120V as that is already present on the main telephone line - I need to "somehow" impose the ringing signal (connect the ringer via a cap or high valued resistor or diode or all of these?).
A simple ringer that can be powered from the main telephone line without loading it too would be appreciated (maybe a 5V1 zener across a 555 timer or something)
Any ideas/suggestions/working circuits?