Full Adder in LTspice using Diodes and single Transistor

I am trying to implement a Full Adder in LTspice using Diodes and single Transistor however i am unable to achieve the desired output. Please refer to the below screenshots. I am unable to add relevant asc file for refernce as the extension isnt supported here


The below article is used as reference.

https://www.instructables.com/One-T...cally a full adder is,full adder can reach 18.

Hi,

you are using three input voltage sources (A, B & C) with ahigh value of 1 V.

Where are the nodes V(n001), V(n002) and V(n006) in your circuitry?

BR

Omkar Shinde said:

unable to achieve the desired output.

Click to expand...

How should your "desired "output look like? Your used LED has a quite high forward voltage. Thus you can not expect the same results as described in the provided link.

stenzer said:

Hi,

you are using three input voltage sources (A, B & C) with ahigh value of 1 V.

Where are the nodes V(n001), V(n002) and V(n006) in your circuitry?

BR

--- Updated Oct 8, 2020 ---

How should your "desired "output look like? Your used LED has a quite high forward voltage. Thus you can not expect the same results as described in the provided link.

Click to expand...

i have attached the desired output image

stenzer said:

Hi,

you are using three input voltage sources (A, B & C) with ahigh value of 1 V.

Where are the nodes V(n001), V(n002) and V(n006) in your circuitry?

BR

--- Updated Oct 8, 2020 ---

How should your "desired "output look like? Your used LED has a quite high forward voltage. Thus you can not expect the same results as described in the provided link.

Click to expand...

the nodes V(n001), V(n002) and V(n006) are my input carry nodes. They are located just before the three 10k resistors. N of diode is almost double the V forward which is true in most LEDs i checked online

Referring to a new article i have created this new full adder using diodes and resistors now
how do i get output in this?

It's wrong to use 1 V input sources in post #1. Review the original article, they are using 5V input. I won't name the circuit an adder unless you have level comparators that convert the analog output voltage to defined logic levels. Is so far the full adder circuit is a kind of bluff package.

Post #5 circuit takes a different approach by using non-inverted together with inverted input signals. The adder core uses only diode logic, but it can't work without external inverters.

A fully featured adder can be cascaded without additional inverters or buffers. In so far neither of the presented circuits is a complete adder.