OT Dialing Rotary Phone on VIOP line

I know this is somewhat off topic but I also know this may be of interest to many here.

I have a Rotary Phone that will not dial on the VOIP system I now have. I am looking at programming a PIC micro-controller to convert the pulse dial signals to pulse tones as an interesting project. I have the circuit to generate the tones but I need some questions answered regarding power.

First I need 2.5V to 5V to power the circuitry, preferably 3.3V. I understand that the line has 48VDC on hook, 6-9VDC off hook, and 90VAC ringing. How do I derive 3.3VDC from that?

Secondly the output in the diagram I have is to create the tones but wouldn't the ringer voltage damage the circuitry if it was connected when it rang.

I have ideas for detecting the dial pulses but I am open to better ideas as well.

Here is the tone generation documentation: http://ww1.microchip.com/downloads/en/AppNotes/00655a.pdf

Thanks for any ideas.

I would seriously get rid of the old phone.
Is phone network a tone or pulse network?
you may be better to fit a modem to the micro controller.
wire the dialer directly to the inputs - write the code to count the pulses. - I don't know if the dialer generates a voltage.

them convert the pulses to a number and send that to your modem.

iant said:

I would seriously get rid of the old phone.
Is phone network a tone or pulse network?
you may be better to fit a modem to the micro controller.
wire the dialer directly to the inputs - write the code to count the pulses. - I don't know if the dialer generates a voltage.

them convert the pulses to a number and send that to your modem.

Click to expand...

I think you misunderstand the point.

I got a tried and true old style reliable GTE phone at a swap meet and having a VOIP line it doesn't dial. I love the look, feel, sound, and ring making it worth having for those reasons alone. After using it you realize how much the quality of phones has diminished. Being fairly handy it seemed like it would be a fun project to create a rotary to pulse dial conversion. I could buy a box to do this for $50.00 but what is the fun in that especially when I should be able to get the parts for less than $30.00.

you might could gut one of those caller id boxes to get a usable voltage

If you get it working let me kow i have one of those wall mount crank type phones id like to turn into a time machine i think this would encourage me to get started on that project, Steve

I believe that the voltages you have are likely accurate for the POTS line but not likely for the VOIP box that you are hooked up to. Did you actually measure these voltages from the VOIP box?