We were tasked to make a two way traffic light.
Ive thought of hwo to make it.

I will use two 15 seconds timer for the Green and Red display and use flip flop for a 3 second countdown for the yellow

The only problem i have at the moment is how to switch/make the transition between the timers.

Like: 15 seconds BCD counter for green, then adter the 15secsonds, id like to switch to the yellow 3 seconds countdown timer then to the Red.

As of now, i just read about the decade counter IC 4017 it could be a good alternative for the BCD 15 seconds timer, but still, how do I make the transitions between timer? THANKS IN ADVANCE!!! )

 

Depending on if you are limited to exactly those times (e.g., can yellow be 5 seconds?), a 4017 will do the transitions for you. And you only need one counter.

 

Depending on if you are limited to exactly those times (e.g., can yellow be 5 seconds?), a 4017 will do the transitions for you. And you only need one counter.

I chose the yellow light to only be 3 seconds ) cuz it would be too odd to see a yellow light on for 5 secs, but yea we are not restricted on that condition )

please correct me if im wrong, but 4017 is only 10 counter right?
and by saying it will do transitions for me, you mean, by cascading them?

Edit1: Im getting an idea already. Thx!!

Edit2: 4017 counter have A - J individual outputs yes? Is it possible to connect all outputs A - J to only 1 LED? What I have in mind is to let the LED stay on for the set period of time