7400 competition entry: Telephone Intercom from TTL

Posted on Thursday, September 15th, 2011 in 7400 contest by Ian

Here’s an entry in the Open 7400 Logic competition: Telephone Intercom from TTL

This is the only craziest project I ever made, beginning in June 2007 and completed in November 2007. Very complex circuits, and uses a lot of IC (about 38 IC). If you think this is a waste, yes! Indeed. However, why do I keep making this project? The reason is, I want to know how the phone working principle and how the analog and digital circuits work.

This entry was posted on Thursday, September 15th, 2011 at 4:00 pm and is filed under 7400 contest. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.

One Response to “7400 competition entry: Telephone Intercom from TTL”

  1. John Mac says:

    My stupid apartment complex has been trying to wire one of those telephone-entry systems kind of like this one for like 2 WEEKS! they need to hire you. enough said

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