traffic signal project

[silvarblade]

heloo people i want to make a 4 way traffic signal for my digital electronics project. we have done latches, flip flops, mux's, demux's timer ic's etc. any idea. check out mine and tell whether it is applicable.

i wont show the yellow light cause i will use a latch . set condition should be green and reset should be red. timer ic's will provide the timing of the signal. now my question is that:

how to make only one led green at one time. by giving the inputs to all from one 555 timer or what.

 

[mneary]

You need to describe your project in a little bit more detail. At this point it looks a lot like a homework problem in which you are expected to provide the solution.

I think that most of us are happy to review your work, but few are ready to do it for you.

Perhaps you've tried to include your work and the attachment didn't work....

 

[silvarblade]

i am working on a schematic as soon as i make it i will upload it k.

 

[silvarblade]

here is the schematic i made it in ewb.

i made the schematic but it is working non only two signals at one time. tell me how to interface 4 signals. i find there are two ways for that:

1. either to give separate input to each flip flop but that will be to big.

2. to divide the signal in to four parts. through a demux.

if i use demux then i can use 1 of 4. that will require 2 inputs . what to do should i use one for j and one for k??

 

[ljcox]

Your circuit is very badly drawn. You should have drawn the Flip Flops as separate entities and there are too many lines going to the same point that could have been roiuted better.

If you want people to help you, you need to make it easy for them.

Here is an example of what I mean. This won't do what you want, it is simply an example of how to layout a circuit so that it is easy to read.

 

[mneary]

You probably want to put each input of the demux on Q1 and Q2.

1Kohm and 100uF is probably running pretty fast, you can try 10K

Some schematic drawing hints: VCC and +5V are probably the same in this circuit. Most of us like to see the VCC mostly the top of the schematic, with branches downward as necessary. If a signal goes several places, such as your VCC does, gather them together before running them to the top.

Also, there's a strong preference for GND to be at the bottom of the page.

If resistors, capacitors, ICs are labeled with references such as R1, R2, C1, C2, IC1, etc it is easier to point out things.

A circuit hint: You're probably not comfortable with negative logic, but the TTL circuits shown (and the mux you'll probably use) will have more strength driving the LEDs with a LOW against VCC rather than a HIGH to GND.

The LEDs presently need resistors in series to limit the current, as 5V is too much to be unlimited.

 

[on1aag]

Hi Silvarblade,

Why don't you try something simpler ?

on1aag.

 

[silvarblade]

hey i guess in this one both the leds light up at opposite times. if so i already done that in this circuit what i cant do is make only one green and 3 red to light up . any help would be greatly appreciated

 

[on1aag]

Hi Silvarblade,

Add the second half of the 7473, change the two 7401 gates in to
four 7410 gates (two packages) and four 270 hm: resistors to drive
the green leds, add four 7421 gates (two packages) and four 330 hm:
resistors to drive the red leds. Delete both 220 hm: resistors and
both 1N4148's.
Connect two inputs of each 7410 gate to the outputs of the flip-flop's
and connect three inputs of each 7421 gate to the outputs of the 7410
gates. All gates have one input left, connect these eight inputs
together and connect them to the output of the timer.
Do you want a schematic ? Are you sure ?

on1aag.