1A2 Key Telephone System - Single Board Control Card скачать в хорошем качестве

1A2 Key Telephone System - Single Board Control Card

This video demonstrates the features of an electronics project I've been working on for a while now. The board can control up to 4 vintage AT&T business phones popular in the late 60's, 70's, and early 1980s. Demonstrated here: AT&T models 2564, 2565 and 2830 phone sets. [Update 05/14/2019: Here's a new video of the new "REV F" board board showing the new Rotary intercom dialing feature using a new 565 phone:    • 1A2 Single Board KSU REV-F1 - Rotary & DTM...   ] [Update 05/04/2019: Working on a "REV F" board that supports rotary dialing to buzz extensions, and a ribbon cable connection that lets one easily connect two boards together for a total of 4 lines/8 extensions. I've completed layout on these boards, awaiting for them to be printed so I can test. These boards are designed in such a way I could sell them. Not yet, more details to come within the year 2019] [Update 03/31/2019: I've been working on a newer, "sellable" version of this board, "REV E", that is more likely to be something I could SELL, pre-assembled. This newer rev has the same features, just a different circuit, and about 50 fewer parts because it uses a PIC chip microcontroller to do most of the logic. Here's an R&D link to that "work in progress", which is pretty far along right now: http://seriss.com/1a2-ksu/rev-e/ Both versions of the board people could print and build themselves; this will always be an "open source" project in that respect] [Update 12/xx/2018: Many inquiries requesting to purchase this board -- NOT FOR SALE YET. At least not yet.. maybe someday. But you can build it yourself (or find someone to build it for you). See my other comments.] Common 1A2 features demonstrated: Hold, call transfer, programmable ringing, Intercom, and touch-tone extension buzzing. Why do this? To bone up on analog circuit design. It was a design goal to NOT use computers on this project (no PIC chips, Arduino, Raspberry Pi, etc), and use only chips/techniques available from around the 1980s. While I did this project for myself, I plan to open sourced the schematics, board design, and circuit description. [UPDATE 11/24/2018]: Here's a web page describing the board and circuit: http://seriss.com/people/erco/1a2-mul... I heavily referenced the Bell System Practices manuals (BSP), books on telephone design, line card patents, and various sources on the web for old phone equipment. Also studied vintage equipment from the period these phones were popular; an AT&T 551a KSU, 400D line cards, ComKey 416 phones. When I ran into trouble with analog design issues, I often conspired with a friend well versed in EE and analog circuit design who kept me on the right track.