3 Input Majority Logic Circuit

[eren.kizildag]

I want to implement a three input majority logic (when at least two of its inputs are 1, the output will be logic 1) by using only 2-input NAND gates. It is required to find the most simple one, with the lowest number of NAND gates, I could construct one with 6 NAND gates, but does anybody know a much simpler way for this? Or six gates is the simplest one? Any help is appreciated...

 

[skeptic2]

Is this homework?

 

[eren.kizildag]

Actually, it is like a homework; it is a part of pre-laboratory which should be designed before coming to lab.. And it will be implemented on lab.

 

[skeptic2]

Using only 2 input nand gates I can't find a solution with less than 6 either.

 

[Bob S]

Can you use 2-input open collector NAND gates (SN7401's) and resistor OR-ing?