Traffic light system - Electronic Circuits Projects Diagrams Free

rway · 4th June 2005, 08:50 AM

I am planning to do a traffic light system for my final year project....

Can anybody help me out with some special features to be added on to the system?

I need also the schematic diagram for the whole system..... Tq!

Best regards!

ljcox · 4th June 2005, 09:15 AM

You won't learn anything if we do it for you.

Your first decision is whether to use a microcontroller such as a PIC or to do it in hardware.

Once you decide that, post your ideas and we can give you guidance.

Len

moody07747 · 4th June 2005, 09:12 PM

im guessing a few 555 timers would do the trick

ljcox · 4th June 2005, 10:20 PM

555 Timers would be a very crude way to do it.

A more elgant way (assuming he chooses the hardware option) would be to use counters.

Len

Arctic Fox · 5th June 2005, 01:09 AM

This would be using the 555 timer (very basic):
http://ourworld.compuserve.com/homep...tm#traffic.gif

k7elp60 · 5th June 2005, 03:24 AM

One thing to consider is the timing of the green,yellow and red lights.
For example the green and red lights may be on the same length of time, while the yellow is only on for a short time. Another thing to consider is that when the East/West is red the North/South is green.
I once did a simple one with a 555 timer as a clock driving a 4017 counter
with some outputs or'd for the red and green and a single output going to the yellow.
If you are going to be realistic and have traffic sensors, then a uprocessor is probably the best way to go.

Arctic Fox · 5th June 2005, 07:27 AM

Quote:

The LED traffic Light circuit controls 6 LEDs (red, yellow and green) for both north/south directions and east/west directions. The timing sequence is generated using a CMOS 4017 decade counter and a 555 timer. Counter outputs 1 through 4 are wire ORed using 4 diodes so that the (Red - North/South) and (Green - East/West) LEDs will be on during the first four counts. The fifth count (pin 10) illuminates (Yellow - East/West) and (Red - North/South). Counts 6 through 9 are also wire ORed using diodes to control (Red - East/West) and (Green - North/South). Count 10 (pin 11) controls (Red - East/West) and (Yellow - North/South). The time period for the red and green lamps will be 4 times longer than for the yellow and the complete cycle time can be adjusted with the 47K resistor. The eight 1N914 diodes could be subsituted with a dual 4 input OR gate (CD4072).

eblc1388 · 5th June 2005, 10:45 AM

The light sequence goes from G--->R--->Y--->G, would it be better for it to go from G--->Y--->R--->G?

Arctic Fox · 5th June 2005, 07:50 PM

Take note of the position notes in the schematic:

Red (north/south) is on the (e/w) side.
Red (east/west) is on the (n/s) side;

The LEDs will have to be positioned on the pole in the correct way.

*now that I'm looking at it, I'm confused... could someone else here check it?

*

eblc1388 · 5th June 2005, 08:02 PM

Quote:

Originally Posted by Arctic Fox

*now that I'm looking at it, I'm confused... could someone else here check it?

*

No, your description is not what the circuit says. Red (north/south) is actually as stated on the north/south side.

Here it goes.

Code:

4017 Pins  Direction E/W    Direction N/S
========================================
    11               R              Y
9,6,5,1              R              G
    10               Y              R
7,4,2,3              G              R

rway · 8th June 2005, 06:05 AM

Tq for all ur replies.... they are very useful to me....

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4th June 2005, 08:50 AM	(permalink)
rway	Traffic light system I am planning to do a traffic light system for my final year project.... Can anybody help me out with some special features to be added on to the system? I need also the schematic diagram for the whole system..... Tq! Best regards!

4th June 2005, 09:15 AM	(permalink)
ljcox	You won't learn anything if we do it for you. Your first decision is whether to use a microcontroller such as a PIC or to do it in hardware. Once you decide that, post your ideas and we can give you guidance. Len

4th June 2005, 09:12 PM	(permalink)
moody07747	im guessing a few 555 timers would do the trick

4th June 2005, 10:20 PM	(permalink)
ljcox	555 Timers would be a very crude way to do it. A more elgant way (assuming he chooses the hardware option) would be to use counters. Len

5th June 2005, 01:09 AM	(permalink)
Arctic Fox	This would be using the 555 timer (very basic): http://ourworld.compuserve.com/homep...tm#traffic.gif

5th June 2005, 03:24 AM	(permalink)
k7elp60	One thing to consider is the timing of the green,yellow and red lights. For example the green and red lights may be on the same length of time, while the yellow is only on for a short time. Another thing to consider is that when the East/West is red the North/South is green. I once did a simple one with a 555 timer as a clock driving a 4017 counter with some outputs or'd for the red and green and a single output going to the yellow. If you are going to be realistic and have traffic sensors, then a uprocessor is probably the best way to go. __________________ The great thing about electronics is unlimited ways to do the job. The only limit is one\'s imagination. I generally think my way is best. Show me a different way. I have an open mind.

5th June 2005, 10:45 AM	(permalink)
eblc1388	The light sequence goes from G--->R--->Y--->G, would it be better for it to go from G--->Y--->R--->G? __________________ L.Chung

5th June 2005, 07:50 PM	(permalink)
Arctic Fox	Take note of the position notes in the schematic: Red (north/south) is on the (e/w) side. Red (east/west) is on the (n/s) side; The LEDs will have to be positioned on the pole in the correct way. now that I'm looking at it, I'm confused... could someone else here check it?

8th June 2005, 06:05 AM	(permalink)
rway	Tq for all ur replies.... they are very useful to me....