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One way would be to use a 74145 to convert the BCD output from the 74190 to 10 individual outputs.

JimB
 
Why do you want to use a chip that is likely to make the circuit more complex?
 
If you use the decade counter you will have all four steps but the whole idea of the 10 steps is the Green / red is on longer.. With the 74190 all four states will be the same length.... You could use 3 74190's cascaded 4 states red/green and 1 state yellow / red... 4 states green /red and lastly 1 state red yellow...
 
There are no 4017 chips available, and my teacher suggested I use a 74190

I just bought 500 x 4107 at 17 cents, so I must have bought the last of the chips IN THE WORLD.
 
As 74190 uses 5V for Vcc, the circuit won't work with just 5V as there are 4 LED to lite on each branch. A 78L05 is needed to get 5V from 12V for the TTL to work properly.

The outputs of 74LS145 (as suggested by Jim) are active low, so either 4 PNP transistors are needed as high side switches for the LED or the 12 LEDs have to be rearranged to fit the 74145 outputs.

Allen
 
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