Continous Traffic Light Circuit

[DjChYnO]

Hey guys I'm new to the forums. I'm trying to build a circuit for a "Traffic Light". I want the three lights (Red, Yellow, Green) to continuously run one arter another. The outputs which are the lights are going to be Light Bulbs.

So far I have look at my notes, (I took electronics throughout High School) and I have the 555 timer and the 74194 TTL IC. Me and my friend figure out that the shift right recirculating circuit will be good for this. Being the 555 timer the clock of the 74194 TTL.

So my questions are, am I on the right track? Where can I find the circuit diagram for this because I'm trying to design this on Multisim.

If not, is there a better and easier circuit for this?

Thanks.

 

[Pommie]

A 4017 would be a simpler solution. The 194 requires the bit to be somehow injected.

Mike.
edit, a quick google for "4017 traffic light" turned up lot's of pages, the first one contained this,
**broken link removed**

 

[DjChYnO]

Thanks alot. I appreciate your help.

So instead of the outputs being LEDs, what do I do to connect it to Light bulbs?

 

[Pommie]

You would need to replace the LEDs with transistors and put the light bulbs in the collector circuit. So, resistor to base of transistor, emitter to ground (0V) and collector to bulb. Other side of bulb to the positive rail. The resistor value depends on the bulb rating and the chosen transistor. You would probably want to change to a large 6V battery as 9V bulbs and large 9V batteries (small ones wont last very long) are hard to find.

Mike.

 

[on1aag]

Hi DjChYnO,

With a little bit more decoding you can get one that
works for both directions.

on1aag.

 

[jst3712]

Hey guys I'm new to the forums. I'm trying to build a circuit for a "Traffic Light". I want the three lights (Red, Yellow, Green) to continuously run one arter another. The outputs which are the lights are going to be Light Bulbs.

So far I have look at my notes, (I took electronics throughout High School) and I have the 555 timer and the 74194 TTL IC. Me and my friend figure out that the shift right recirculating circuit will be good for this. Being the 555 timer the clock of the 74194 TTL.

So my questions are, am I on the right track? Where can I find the circuit diagram for this because I'm trying to design this on Multisim.

If not, is there a better and easier circuit for this?

Thanks.

Hi, I made one using a PICAXE microcontroller chip. Bit of programming involved, but the beaut thing about these is you can program it to work how you want, with precision.
For a very basic setup, the finished product would just be microcontroller chip and some transistors for the outputs.

You can add inputs too.
Mine was setup for 2 directions of traffic, and was able to detect pedestrians waiting to cross and cars waiting (just like those underground sensors). Pity I can't find my schematic, but you can definately do a lot more with a microcontroller than a 555/4017 setup

Jason

 

[DjChYnO]

Thanks alot, now I have to design it on Multisim (I hate it) lol

 

[Willbe]

Thanks alot. I appreciate your help.

So instead of the outputs being LEDs, what do I do to connect it to Light bulbs?

Don't forget that incandescents draw 10x to 15x the steady state current for a few dozen mS.

 

[rham]

hi..
i want to make a circuit of a traffic light (red, yellow, green) using a 555 timer.. but not using the counter ic.. pls help me... thnx...

 

[blueroomelectronics]

Why not use the counter IC?

 

[Boncuk]

hi..
i want to make a circuit of a traffic light (red, yellow, green) using a 555 timer.. but not using the counter ic.. pls help me... thnx...

How do you want to control three different coloured LEDs with one output?

Instead of using a counter you might use three timer circuits, the first one as astable and the follow-on timers as one-shots to trigger the next.

Timing has to be super accurate!

Boncuk

 

[Ubergeek63]

Hi DjChYnO,

With a little bit more decoding you can get one that
works for both directions.

on1aag.

Technically more inputs to less outputs is encoding. You are just encoding ten inputs to three outputs for two different signal faces.

Dan

 

[rham]

pls....

that is my prof. said im not using a counter ic...

any ic can do but not counter ic...

help me... pls...

 

[Ubergeek63]

that is my prof. said im not using a counter ic...

any ic can do but not counter ic...

help me... pls...

so make a Johnson counter from a shift register IC or F/F. then make it from like the 4017 circuit.

 

[rham]

thnx

cn u gve a diagram of that circuit!!

thnx..

 

[blueroomelectronics]

Wouldn't that be cheating if we do your homework for you?

 

[messyjome]

hello guys..

hey, i badly need your help in coming up a TRAFFIC LIGHTS Circuit that has roads A,B,C,D where AB is the priority road. these have RED, YELLOW and GREEN lights. For priority roads AB, GREEN light should stay for 5 mins while for roads CD, GREEN LIGHT stays for 3 mins. YELLOW lights stays for 30secs. As per our professor, this circuit will only use basic gates, ICs like 74194 or 74192, 555 timer.
To add up to the complexity of this circuit, this should have a time display.

please help. i am very much thankful to all help i could possible get.

hey, u can also contact me at 09228408714. my name is jome

 

[Ayaskanta]

the simplest method is to use a priority encoder (such as 74148) in cascade with a ring counter (7495)
the priority encoder is to pick the roads and the ring counter to drive the lights. Now the counter uses clock pulses to rotate its outputs (in this case the traffic lights) so you need to use a clock with varying time periods so that a particular light stays ON for a particular time period

 

[MrDEB]

here is the start using a 74ls175

could maybe be considered acting like a 4017??
just add a 555 for timing, perhaps another 74ls175 with some diodes tied to several outputs so some of the outputs stay on longer that others.
as for the display maybe 7490 w/ 7475 + 7447
IMHO this may be a good strat??