Logic question, 3 input OR to 2 input OR

In summary: To get a four input OR simply feed two Two input ORs into a third Two input OR. Using three two input NANDs instead of ORs, do the same thing, but put inverters before each NAND input. This requires six (ugh) inverters. The problem using cascaded NANDs is that they automatically give you an AND (first stage)- OR (second stage) condition. What you want is an OR-OR condition. The simplest way to get this would be to feed two NORs into a NAND.
  • #1
mathrocks
106
0
Hi, I'm trying to convert a 3 input OR gate using only 2 input OR gates . How exactly will this look like?

Thanks
 
Engineering news on Phys.org
  • #2
Convert it to what?
 
  • #3
enigma said:
Convert it to what?

to two 2 input OR Gates
 
  • #4
I'm sorry. I'm still a little confused what your problem is asking.

Do you have the complete problem statement, or is this for independant work?
 
  • #5
enigma said:
I'm sorry. I'm still a little confused what your problem is asking.

Do you have the complete problem statement, or is this for independant work?

Ok,

I need to build a 3 input OR gate using only 2 input NAND gates and inverters. The only way to do this is if I build the 3 input OR gate to use 2 input OR gates and then convert that into a NAND.

If you know how to build a 4 input OR gate using only 2 input OR gates that would be helpful also.
 
  • #6
I think I answered this in another post. Cascade.

This is pretty simple. Draw out the truth table. You can get this result using one cent diodes...

Cliff
 
  • #7
Simple, ground one input.

KM
 
  • #8
Kenneth Mann said:
Simple, ground one input.
I believe you read the problem statement incorrectly.

- Warren
 
  • #9
You're probably right. The original statement isn't very clear. If the author wants to ust (multiple) dual input ORs to create a three input OR, the answer is just as simple. Feed the output of one OR to one input of a second OR. Then, the remaining three inputs comprise a Three Input OR.

KM
 
  • #10
To get a four input OR simply feed two Two input ORs into a third Two input OR. Using three two input NANDs instead of ORs, do the same thing, but put inverters before each NAND input. This requires six (ugh) inverters. The problem using cascaded NANDs is that they automatically give you an AND (first stage)- OR (second stage) condition. What you want is an OR-OR condition. The simplest way to get this would be to feed two NORs into a NAND.

KM
 

1. What is a "Logic question"?

A logic question is a type of problem or puzzle that involves using critical thinking and reasoning to find a solution. It often involves logical operators such as "AND", "OR", and "NOT" to determine the correct answer.

2. What does "3 input OR to 2 input OR" mean?

This refers to a specific type of logic question that involves three inputs and two outputs connected by "OR" gates. The goal is to determine the correct combination of inputs that will result in the desired outputs.

3. How is this type of logic question solved?

To solve this type of logic question, you must create a truth table that outlines all possible combinations of inputs and outputs. Then, you can use logical reasoning to eliminate incorrect combinations and determine the correct answer.

4. What are the applications of "3 input OR to 2 input OR" logic questions?

Logic questions in general have many applications in computer science, mathematics, and other fields. Specifically, "3 input OR to 2 input OR" logic questions can be used in circuit design, programming, and problem-solving.

5. Are there any tips for solving "3 input OR to 2 input OR" logic questions?

Yes, some tips for solving these types of logic questions include starting with simpler cases and working your way up to more complex ones, using process of elimination, and double-checking your answers. It can also be helpful to break the problem into smaller parts and solve them one at a time.

Similar threads

  • Electrical Engineering
Replies
8
Views
1K
Replies
2
Views
307
  • Electrical Engineering
Replies
9
Views
1K
Replies
55
Views
3K
Replies
4
Views
773
Replies
39
Views
3K
  • Electrical Engineering
Replies
3
Views
2K
  • Electrical Engineering
Replies
7
Views
951
Replies
4
Views
1K
Replies
3
Views
2K
Back
Top