Hi, I've been tasked with an assignment, I've basically got to build a circuit that will take a 4 bit BCD input for the numbers 0-9 and output the correct number to the 7 segment display. I've only just started at uni after time out from college and i'm struggling abit.

Ive managed to do a truth table and the Karnaugh maps for each of the 7 segments to minimise the logic expressions, but that's as far as ive got, when I try to convert the expression to NAND it wont simulate correctly so I assume im doing something simple wrong but I just cant see it.

I'm struggling converting the expressions to 2 input nand gate circuits, could someone help me with this one below which is for LED A.

I'm using proteus to build and simulate the circuits but I cant successfully convert it to NAND only and for it to work correctly. Any pointers or help will be much appreciated!!

Many thanks

Chris

Ive managed to do a truth table and the Karnaugh maps for each of the 7 segments to minimise the logic expressions, but that's as far as ive got, when I try to convert the expression to NAND it wont simulate correctly so I assume im doing something simple wrong but I just cant see it.

I'm struggling converting the expressions to 2 input nand gate circuits, could someone help me with this one below which is for LED A.

I'm using proteus to build and simulate the circuits but I cant successfully convert it to NAND only and for it to work correctly. Any pointers or help will be much appreciated!!

Many thanks

Chris