Hi, Andy,

>Do you mean you can't see why it's a problem when you apply ringing
>voltage (which, BTW, is on the order of 70VAC on top of the 48V DC bias),
>but not when they apply ringing?

Yes, I cannnot to see it yet. I whould like to review a few detailed
examples of the Line Feed/Ring Feed Circuits. Also, it whould be nice
to know what is permited(in digits) and what is not by a telephone
company.

>The reason for this is that the phone company uses a switch to
>disconnect its sensitive input circuits while applying ringing.

But in case of using a line monitor to protect the sensitive
circuits they whould not differ an incoming ring or thier native
one is present on the line.

"but it looks like they are protected even from this"
>Well, the seatbelts and airbag(s) in your car are there for your
>protection, but you don't go deliberately driving straight into
>brick walls at speed, do you!?

No, these are just decoration of protection for such kind of
recreations. A God could protect more of a good wall. But car's
cabin can protect of raining as an example, and this ability is
often used by us as many others.

Thank you,
Oleg