[HELP 4 WAY- TRAFFIC LIGHT] Can someone tell me what is wrong with our schematic?

When we run it through the Circuit wizard it goes without errors but when we imply it on a breadboard it is stuck on "4", it doesn't countdown.

Then there is likely a wiring error on the breadboard.

Where are your current limiting resistors? Also, your 555 timer astable multivibrator circuit is wrong.

That's an interesting name for a traffic light - at the top of the diagrams.

Mike.

Cmos logic IC inputs must never be floating. Your CD4017 IC has its EN and R inputs floating. They MUST be at a certain logic level.
I agree that you did not read the datasheet for the CD4511 and have probably destroyed it by missing the output current-limiting resistors.

The CD4511 is designed to drive ONE display but your circuit has four displays in parallel. The LEDs in the different displays do not match so some will be very dim or will not light. Why not use a CD4511 with current-limiting resistors for each display?

Pommie said:

That's an interesting name for a traffic light - at the top of the diagrams.

Mike.

Click to expand...

Hahaha, students will be students.

The discrete LEDs are also lacking limiting resistors.

Plus...they are wired, or at least drawn, in a completely confusing, messy and absurd way.