Binary Counter using Discrete Transistors for 7 Segment Decoding
This video demonstrates a 4 digit 7 segment multiplexed binary counter using an array of discrete transistors to perform the segment decoding process.
Yes, I know this could be done with just a couple of chips, but this was more about building up the gates from discrete transistors rather than minimizing the hardware.
The overall circuitry is laid out in a general fashion at the following link: https://drive.google.com/file/d/0BxvgerQiutI-QjEyY3hrcEhIVnM/edit?usp=sharing. It provides for general counting and offers additional capabilities such as counting up and down, loading a specific start value, and reseting the start value to zero.
The decoding was determined using a Karnaugh map and creating a series of SOPs for the segments. The map can be found at the link: https://drive.google.com/file/d/0BxvgerQiutI-R3FPME91WTF4YUk/edit?usp=sharing. The "And" gate is shown in the video: http://youtu.be/EFcF1fehQrU. The "Or" gate is shown in the video: http://youtu.be/0TCXUa8DYDs....