LOGIC GATES project

[logan_dslasher]

hi! a friend asked  for help regarding his project involving logic gates..

its a simple illustration o about how logic gates function.. is it possible to integrate all the kinds of logic gates into one circuit? for example, the output of a NOT gate will be one of the inputs of am AND gate while the other input is the output of a NOR gate.. is that possible? what should i use? i prefer IC than transistors..

Can you please show me how.. tahnks a lot..

 

[Staigen1]

Hi Logan

Do you mean like this?

//Staigen

View attachment 38627

 

[logan_dslasher]

GREAT! but what is that? is that an IC? what IC?

 

[Staigen1]

Hi Logan

Its logic gates, dont bother about pin-numbers, i forgot to erase them!
Just see them as logic gates. In reality its 3 IC:s, but they have more
logic gates, the IC containing the NOT gate(usally called inverter) have
6 gates in the same IC, and the other 2 have 4 gates in each IC. You
can use CMOS or TTL, it dosent matter, you can't mix them thou, well,
sometimes you can do that too. Get yourself a pair of good books about
TTL and CMOS, and you will soon learn how it works. The picture is
showing what you requested.

//Staigen

 

[logan_dslasher]

Audioguru and I had a discussion about logic gates last night on MSN. You were "away" so i didn't bother PM-ing you.. I understand that they are 3 IC's..

just a question.. an IC can contain up to six gates, then why is it not possible to have different gates in a single IC? or is it? I've been looking at datasheets and i think haven't seen an IC that have multiple gates in them..

 

[Staigen1]

Hi Logan

Look at CD4000, it have two 3-input NOR gates and one NOT(inverter)
But it is unusual, i admit that.

//Staigen

 

[logan_dslasher]

WAAaaaa!!!

just a question.. an IC can contain up to six gates, then why is it not possible to have different gates in a single IC? or is it? I've been looking at datasheets and i think haven't seen an IC that have multiple gates in them..

It is possible!! It's just now that i found one.. can i use this?

 

[Staigen1]

Hi Logan

Sure, why not?

//Staigen

 

[logan_dslasher]

Is there an IC that has AND and OR instead of NAND and NOR just like in a 4572? Can you please help me find one.. I always end up with 4572.. I prefer using an AND and a NOT.. tahnks...

 

[Staigen1]

Hi

For an OR: Connect pin 4 and 5, output at pin 3
For an AND: Connect pin 12 and 13, output at pin 11
Also think of that every input MUST be connected to
something that have a logic state!

//Staigen

 

[logan_dslasher]

DUH!?! could i be dumber that Dumb&Dumber?! Of course, what are the inverters for?!

thanks Staigen! I hope the IC is available in the stores..

 

[logan_dslasher]

Just as i predicted! It's not available.. what now? anybody knows a replacement..

i have searched datasheets and i came up with..
SN7451
CD4019B
5400
7400

there's also the AND-OR-INVERT gates in HD74 and HD74S series..

what to use now?  please advise.. i hope these are available..

 

[wvengineer]

an IC can contain up to six gates, then why is it not possible to have different gates in a single IC? or is it? I've been looking at datasheets and i think haven't seen an IC that have multiple gates in them..

If you just think of it as digital logic than you could use a programmable logic device.  Like a GAL chip or a FPGA where you don't worry about the gates so to speak but just come up with the logic expression using truth table, K-map, or whatever method you prefer.  I think in this case this is not what you want I just thought I would mention it though.  I think some FPGA's have a million gates...not sure, but I know the ones we used had tens of thousands of gates.  Neat stuff.  I also seem to remember being told that NAND gates are cheaper than AND so people would adjust their logic to use NAND gates for production projects to save money.  I also figure that whatever logic configuration is the most popular is what will be produced.  Sorry just rambling.   

 

[logan_dslasher]

hi wvengineer! thanks for the additional info..

i think i'll just use TWO IC's for the project..

 

[DaveP1]

In order to demonstrate the logic functionality that you describe you actually don't need to use any logic gates at all.

I have emailed you an idea that uses 3 switches, one resistor, one LED and a 9 volt battery.

 

[logan_dslasher]

i received an email at my Yahoo from a new member of the eLab.. it was hs idea on how

 

[logan_dslasher]

Hi dave!

thanks a lot for your idea but it is really important that the circuit contains real gates..

the next time, attach files in jpg, or png format.. if your attachment is in bmp format, simply use "save as..." in the file menu and below the file name, you'll see a dropdown menu what format you want it to be saved. choose JPEG..

tahnks again for the idea..

 

[Staigen1]

Hey Logan

You can also use one of the 3-input NOR gates of the CD4000 IC,
reducing the amount of IC:s to just only one, dont forget to connect
the other gate:s inputs to something that have a logical state! But
i belive the project is a scool project that needs to have all the
gates. But a little text about it can be good to present to the
teacher, so he see that you have penetrated the question properly!

[move] ;D > 8) ??? : :-[ :-X :-\ :-* :'( ;D > 8) ??? : :-[ :-X :-\ :-* :'([/move]

//Staigen

 

[steven2]

View attachment 38641