4 Way Traffic light Circuit

I have Assembled this circuit several time on a Breadboard and I can Not get it to work Correctly ,
If I am understanding the schematic Correctly this is how it is Supposed to be Assembled .
Please looking at the Screen shot and let me know Why it is not working . thanks

Maybe upload the .fzz sketch with the 7th button in the reply toolbar, because there are lines that overlap, ie green yellow, orange junction, where you can’t see what was intended.

Ok i will redo it thanks

One problem is the diode that should connect to pin 9 is floating (it ends before connecting anywhere on the IC). This also doesn’t indicate what you are using for a supply voltage, 5V won’t work the schematic suggests 12V but 9V may also be enough. At 5V the led voltage drops won’t light the leds. As @Old_Grey suggested uploading the fzz file would make life a lot easier (as well as indicating what the supply voltage is).


As Requested Here is the Fzz.file Also this is a 12v circuit and the schematic is on Talking Electronics . But i have uploaded that also for you to see … TC BB.fzz (26.0 KB)Screenshot_8

You have two problems, there isn’t a connection between the grounds on the two breadboards and pin 9 isn’t connected to its associated diode. Either of those will cause problems if they are really there in the physical circuit. You also didn’t show a power source (I assume you have one) so I added a 9V battery as the power source. If you click on a pin in any view all the connections to that pin will light up yellow. Make sure all the connections that should light up do. You may also want to route the schematic and compare the result to the original (I did so but didn’t save it). The sketch below has the corrections.

TC BB_fixed.fzz (26.6 KB)


I am Unable to Open the TC BB_Fixed file it must be in a Zip file so it says .???

I just downloaded the fzz (to make sure nothing bad happened on the upload), started fritzing and did file->open and selected TC BB_fixed.fzz and it loads fine in 0.9.3b on Win7. Yes it is a zip file, most Fritzing files are.


It opens for me.

Another hint is the breadboard acts like a real BB, so you don’t need those orange wire links between diodes. If you look at a part that is put in the BB, eg LEDs, you will notice the whole row of holes turns to green dots, that is telling you they are all connected.
Also you can click on a green dot or bendpoint and everything connected will turn to yellow dots.