telephone line monitoring
Hi,
I am going to use a stamp to create a simple home telephone exchange and
I need to know how I can test to see if an outside line is busy.
I have discovered that the voltage on a line drops when it is in use. Can
anyone suggest a simple circuit for measuring the voltage across a
telephone line preferably with optical isolation.
Thanks in advance,
Jim
I am going to use a stamp to create a simple home telephone exchange and
I need to know how I can test to see if an outside line is busy.
I have discovered that the voltage on a line drops when it is in use. Can
anyone suggest a simple circuit for measuring the voltage across a
telephone line preferably with optical isolation.
Thanks in advance,
Jim