kgdykes@watmath.waterloo.edu (Ken Dykes) (11/17/88)
Someone asked if there was a way to "cross connect" two lines to get a 3-way conference call effect. Someone else asked if there was a way to restrict long-distance dialing. Well, there is a book of do it yourself phone projects, while i personally consider simplistic and definetely dated on what ICs are available, will provide "functional" circuits for the above two problems and others toys. ok, so i cant spell definitely Its a "SAMS" project book. SAMS Electronic Telephone Projects, 2nd edition by Anthony J. Caristi ISBN 0-672-22485-2 I found it at a local electronics parts store. It has introductory chapters on "phone wiring" princicples (basic) The back of the book says "To order" call 800-428-SAMS They appear to accept all major credit cards. Other projects included: - replace bell ringer with electronic ringer - broadcast phone conversation to nearby FM radio - CB telephone patch - hearing impaired lamp for ringer - 32 number memory - convert single phone into a two-line model and others. As i said, not great examples of electronic design, but functional, and possibly provide ideas or avenues-of-thinking for you.
rosso@uunet.UU.NET (11/28/88)
In article <telecom-v08i0183m01@vector.UUCP> kgdykes@watmath.waterloo.edu (Ken Dykes) writes: >Well, there is a book of do it yourself phone projects, while i personally >consider simplistic and definetely dated on what ICs are available, >will provide "functional" circuits for the above two problems and others >toys. ok, so i cant spell definitely >Its a "SAMS" project book. > SAMS Electronic Telephone Projects, 2nd edition > by Anthony J. Caristi > ISBN 0-672-22485-2 Data books from IC manufacturers are another good source of projects. Many of them have "applications notes" containing full schematics to illustrate the use of the chips they make. The latest databook from Exar Corp. (2222 Qume Drive, San Jose, CA 95131) has a circuit for a speakerphone using their speakerphone IC, complete with schematic diagram, parts list, and even a printed circuit board layout. Also in the book are full circuits for a pulse/touch tone phone, and several modems. Most databooks are free for the asking in single quantities (Exar was handing out copies at a career fair). Many IC makers also sell evaluation boards for engineers to experiment with new chips. This is a great way to experiment with the latest technology. Ross Oliver uunet!sco!rosso