Traffic Lights

[George]

Daithi, I used the circuit on the website you provided and it seems not to work. I also used the advice you gave at the end of the reply and removed the diode. The yellow light does not cut on and the red and green light just stay on. I used the multisim program. Here is a picture. Please help from anyone

I think I see what is wrong. If you look back to the link that Daithi posted you need to have pins 1, 5, 7, 9 in series with green, 10, 11 in series with yellow, and 12 in series with red. Please take a closer look at your schematic. I might be getting confused between Q# and pin number so please correct me if I am wrong. I never made this circuit.

Regards,

George

 

[Shubham89]

Red led is always glowing . Other things are working fine. I´m working with Proteus (isis).
Any suggestions?

 

[pablo medina]

[Quote = "Admin, post: 138, miembro de: 1"] Este hilo es para la discusión del circuito Semáforos [/ quote].
Buenas tardes, el circuito para que funcione bien, cambia la resistencia de 47K por una de 33K o 22K, suerte

Buenas noches, el circuito con el fin de que funcione bien, cambia la resistencia de 47K en una de 33K o 22K, suerte
Good evening, the circuit in order that it works well, changes the resistance of 47K into one of 33K or 22K, luck

 

[zacnozi]

hey everybody!
i am building this project using proteus but due to some reason only my yellow and green lights are working and their timing is same for the both of them..
any help would be appreciated.

 

[Jaron Pirtle]

hey everybody!
i am building this project using proteus but due to some reason only my yellow and green lights are working and their timing is same for the both of them..
any help would be appreciated.

Okay, What I saw was your voltage area should change to to 12v and there shouldn't be ground up there also just your positive voltage and the 22k resistor that is hooked to pin 3 of your 2nd 555 timer change that to 47k. Try those and see what happens....

 

[zacnozi]

Okay, What I saw was your voltage area should change to to 12v and there shouldn't be ground up there also just your positive voltage and the 22k resistor that is hooked to pin 3 of your 2nd 555 timer change that to 47k. Try those and see what happens....

i did what you told me but no change.....

 

[Jaron Pirtle]

i did what you told me but no change.....
Try changing that battery to only just a 12v input unless you try to connect a wire from the gronud on the bottom to the battery.... try either one of those....

 

[Jaron Pirtle]

Do you plan on building it on circuit board

 

[Søren]

i am building this project using proteus but due to some reason only my yellow and green lights are working and their timing is same for the both of them..
any help would be appreciated.

Always trouble-shoot (and build) in a modular fashion!
First get the left 555 working on its own. Remove the wire going to pin 8 of the right 555 and see if you can get the red led to go on/off then.

Didn't help?
Remove the "R" in "470R" (R5 in your schematic), that may well be what's causing the problem.

When the red LED is working, reconnect and see if it's all working together.
Please post your results so far.


EDIT: And please reconnect the battery ground connection - won't work without it.

 

[Madness]

Hi, I tried this circuit & it failed the first time. That try was the result of following the schematic, verbatim. For example, the line from the 100k resistor on first chip, running to pin 8 on the second chip. It was broken where it crossed pins 4/8 on the former chip, clearly indicating no connection. But there was a solid cross at the aforementioned line & the 470 resistor going to the red LED, which then appeared to continue on to power. Same w/ the yellow (had no orange) LED running off the second chip. Its 220 resistor appears to connect to pin 8 & then to power. So a bit of a "boo-boo'ed" schematic. But once I figured out that those were errors & corrected them, the circuit worked fine.

Second, are the resistor & cap values, critical? I mean increasing the 100k &/or 47k resistors caused the circuit to act erratic (i.e. the green & yellow or green & red, flashing or slowly changing, alternately). Also, increasing either of the 100uF caps, causes similar behavior. So, is it not possible to slow the cycle down?