Circuit

[Bassey]

How U De?
Pls, Can I Get A Complete Circuit Diagram On Private Branch Exchange.

 

[blueroomelectronics]

You probably can't unless you work for the company that makes your PBX.

 

[Mikebits]

How U De?
Pls, Can I Get A Complete Circuit Diagram On Private Branch Exchange.

You don't ask for much do you?

Your best bet for building a PBX is to use VOIP. So incoming calls go through a VOIP modem. All PBX functions are handled in software on a dedicated PC. Free software is available from
Asterisk :: The Open Source PBX & Telephony Platform |

For the POTS end you can purchase Line interface cards that plug into the PC. Check here. analog | Digium - The Asterisk Company

For a good explanation see here.
**broken link removed**