Ring detection method

[protokatie]

Maybe the "technician" can help here.

The details of my project are un-important, but is there an easy way to make a circuit that can differentiate a ring on a VOIP/landline from any other use of the line? I guess I could gut an old phone and use that, but I would rather use a more "polite" route.

And yes, this has to do with my Tardis. (damn roomate is too loud on my VOIP line, so anything to muffle the sound...and make a light blink at the top during rings...)

[DaOld Man]

BYORD (Build Your Own ring Detector):

This will work with regular land line phones, but I dont know about the VOIP. But if the VOIP will ring a regular phone, I dont see why it wouldnt work.

http://www.epanorama.net/circuits/telephone_ringer.html

I made something similar to this years ago to flash a lamp for my mom when the phone rang, she was going deaf at the time.
I cant find the schematic to it, but it is similar to the one linked, except instead of C1, D1, and D2, I used a small neon bulb. The neon bulb conducts at around 90 volts, so it worked very well.
I also used a triac compatible Opto Isolator and a triac to turn on the 120 volt lamp, but if you just want to blink an led you wont need a triac.

And if you would like to know when the phone line is being used by someone else, or a dial up modem, or fax machine, here is another circuit that will tell you that: (Thanks to Aberto Ricci) (again, not sure about VOIP usage)

http://www.riccibitti.com/quickdesigns.htm