I've finally finished a set of design improvements that I've known were possible for a long time. There are 27 monadic ternary gates. However, 18 of them are "binary" in that they only have two possible outputs. This could be -/+, -/0, or 0/+. Regardless, each can only represent two possible outputs. Some of these gates could be implemented with just a transistor, or simplified by replacing one of the comparators with a transistor. I originally did not do this because I was trying to get every last bit of value out of the comparators I had selected and ensure that they would be an adequately versatile to do the job. They are, but if I can achieve more simplification by adding transistors into the mix, then so be it.

I am using the N-Channel 2N7000 and the P-Channel VP2106. This is because they fit the vital design specifications of being cheap and available in quantities of 1. I also tested a Depletion-Mode N-Channel MOSFET, the LND150, but couldn't get any joy from it. The 2N7000 all by itself can be used to build a 1 (0--), 2(+--), or H(++0) gate. The VP2106 can be used to build a 1, 8(++-), or H gate. So between the two of them, I can build 4 different monadic gates instead of using a voltage comparator. This saves board space and components.

These four monadic gates have also served as component parts of the following monadic gates: 5, 6, 7, A, B, F, G, M, and N. Each of these gates used to take either an entire LM319 or an entire LM393. Now I can build them with just a transistor and 1/2 of an LM319 or LM393.

Lucky for me, some of these gates have been showing up as fairly common when I have been trying to build up more complex structures. This should make some of the bigger circuits easier to build, including the Sum Gate that keeps taunting me.

Here is the schematic.

An important note in adding transistors is the change in thresholds. Because I could arbitrarily select thresholds between the different logic levels when using voltage comparators, I chose +1V and -1V for the sake of simplicity. Transistors on the other hand have built-in thresholds based on their chemistry; about 0.6V. I'll just need to keep in mind that any input arriving at a gate that uses a transistor will need to have stricter tolerances than what I have previously considered acceptable.