Yes. Three 2-input gates will work:Okay, then is this possible to make 4 input OR gate using 2 input OR gates? Please help me with it. Thanks.
Special thanks to you for pointing out the mistakes in simplified expressions. I have corrected the mistakes in the new attachment. Please have a look to see if I'm still missing something. Sorry, I didn't highlight anything in the attachment this time.The truth tables are all correct.
B function can be reduced to w+x'+y'z'+yz
C function can be reduced to w+x+y'+z
You forgot to group the minterm 5 for D
G function can be reduced to w+xy'+yz'+x'y
It takes some practice to notice the bigger groups.
You need only 4 inverters at max. You can create the inverted signals for the 4 inputs and then use them more than once. Don't spend NOT gates each time you need an inverted input.
I 'm not familiar with 40XX series. It's important knowledge, but I admit of not having acquired it yet. The 74XX series is more familiar to me and tested to be sturdy enough for educational purposes. They work ideally with 5V, but 3AA batteries will do most of the time. 2-input gates some in ICs of 4, 3-input gates come in ICs of 3 and inverters come 6 in each IC.
The switches used in the video are push-buttons, as you said. I would use double-pole double-throw switches, so I don't have to keep them pushed. Like these ones: http://img.diytrade.com/cdimg/860392/7969147/0/1301298514/No_lock_self-locking_switch.jpg
Another good thing about dual throw buttons is that they provide Ground as an input while OFF, not an open circuit, and IC inputs need to be tied to a voltage level at all times.
You can't use a numpad for your application, because you want to input binary, not decimal.
by Aaron Carman
by Jake Hertz
by Aaron Carman
by Aaron Carman