Hi have a simple traffic light project using a 555 timer, 4 bit BCD and quad nand gate I don’t where to start on the logic and Boolean algebra used light the traffics lights for the given time period

 

From the schematic you can see that LS93 is a binary counter (NOT BCD) It counts from 0 to 15. As the first output was not used, the remaining 3 outputs would give you all the EVEN events ie 0,2,4,6....14.

The three LEDs namely /R, /A,/G are all active LOW so you have to create a truth table of the 3 colored LED against the 8 inputs 0...14.

Are you able to male the truth table yourself or you need more help?

Allen

 

Welcome to AAC!

What does "SL" stand for?

Where did you come up with the restriction for the decode logic to be implemented with a quad 2 input NAND gate?


Do you understand that you need to use the full count from the counter?