i want to build a PBX, with only internal telephon lines (no CO interface at the begining) let us say 4 internal lines,
can any body suggest schamatic or block diagram or anything to start???
i have some experience (2 years) in installing SIEMENS PABX (up to 500 line) now i hope to start to build my private PBX.
thanks alot for ur time
have a nice day
Is your desing intended as a product? Will it need to cover various interfaces in the future or is it just a simple design? You will need a microprocessor and software to implement a smal PBX. What is the functionality that your PBX needs? Probably need DTMF detection, Off hook detection, Ringing maybe dial tone certainly needs line feed. What kind of IC's do you intend to use? Are SLIC and CODEC IC's available at your location? Can you clarify your needs?