Quote Originally Posted by BobK View Post
Hello, ultramegaok

You will not be able to send any thing out to the phone line through a bridge rectifier!
The only thing the bridge rectifier is good for, on a phone line, is drawing power FROM the phone line to power some circuitry. You need to use a 600:600 isolation transformer. Go to www.microchip.com and lookup application note AN854. There in Figure 1 is an example of what it takes (their engineer's opinion) to communicate over the phone lines using a PIC and a few discrete components.

Pretty much any circuit today uses the transformer to isolate the product from the phone line. There are several alarm dialers on the market that use opto-isolators and P-mos relays to connect to the phone line. Did you look at the site that I listed on my first reply?

BobK

Thanks BobK
I have read the website from your first reply which helps me a lot to undertands how telephones work, I was trying to avoid the transformer because I don't have one on hand rigth now, but I think I need to go to radioshack and get one. That seams the most safest way to connect the pic...... I let you now my progress...Checking AN854.