Disclaimer: This is an example of a student written essay.
Click here for sample essays written by our professional writers.

Any scientific information contained within this essay should not be treated as fact, this content is to be used for educational purposes only and may contain factual inaccuracies or be out of date.

# Design of Traffic Light System

 ✅ Paper Type: Free Essay ✅ Subject: Engineering ✅ Wordcount: 3738 words ✅ Published: 30th Aug 2017

Contents

LIST IN Tab;e

List in Figure

## Design Specification

Design specification prepared for a single main and sub -road junction in rural area is given below

• The green light for the main road will be stay ON for 30s.
• The green light for the side road will be stay ON for 20s.
• The amber caution light will say ON for 5s between changes from green to red.
• Main road and side road timing countdown should display in a 7segment display.
• Sequence change of the traffic lights show in the Appendix I.

The traffic light system for a single main road and sub road junction in a rural area.

## Complete Block Diagram of the traffic light system

Figure 2(block diagrammed)

The FSM description stands for “Finite state machines”. the Finite state machines are the most common controllers of machines. It’s In the example Traffic light, the intersection of a main road with a side road is controlled by two traffic lights. FSM has three inputs (T1, T2 and T3) AND six outputs (Rm, Am, Gm, Rs, As and Gs)

In here

Rm is Red light for main road

Am is Amber caution light for main road

Gm is Green light for main road

Rs is Red light for sub road

As is Amber caution light for sub road

Gs is green light for sub road

T1 time is 30seconds

T2 time is 20seconds

T3 time is 5seconds

Complete Moore model state diagram for traffic light system

## State diagram Table

 P.State N.State INPUT Outputs Gm Am Rm Gs As Rs 1 0 0 0 0 1 T1 0 1 0 0 1 1 T3 0 0 1 1 0 0 T2 0 1 1 0 1 0 T3

Table 1(State diagramme)

State Assignment in Gray code

Here using gray code for states

State transection table

Here using D type flip flops for design a circuit

 P.S Q1 Q0 N.S Q1+ Q0+ INPUT Gm Am Rm Gs As Rs 0 0 0 0 0 0 1 0 0 0 0 1 0 1 T1 0 1 0 1 0 1 0 1 0 1 0 0 1 1 1 1 T3 1 1 1 1 1 1 1 1 0 0 1 1 0 0 1 0 T2 1 0 1 0 1 0 1 0 0 1 1 0 1 0 0 0 T3 0 0

Table 2(D type Flip Flop)

Simplified equations for the system.

From Laws of Boolean Algebra

(

The equations are,

## Circuit simulation using Multisim software,

Figure 4 (main red and sub green for 10s)

Figure 5 (Main amber and sub red and amber for 2s)

Figure 6(main red and sub green for 10s)

## Timing Counter

Figure 10 Main green and sub red

Figure 11 (Main amber and sub red and amber)

Figure 12 (Main red and sub green)

## Task 4

 Item name quantity Price (Rs) 2 pin AND gate IC 5 120Ã-5=600 3 pin AND gate IC 2 120Ã-2=240 2 pin OR gate IC 1 40Ã-4=40 3 pin OR gate IC 1 40Ã-1=40 2 pin XOR gate IC 1 40Ã-1=40 Dual JK FF IC 10 100Ã-10=1000 Dual D FF IC 1 100Ã-1=100 DCD 7 Segment decoder IC 5 100Ã-5=500 7 Segment display 5 50Ã-5=250 NOT gate IC 2 40Ã-2=80 Red color LED 2 5Ã-2=10 Amber color LED 2 5Ã-2=10 Green color LED 2 5Ã-2=10 wires 20m 15Ã-20=300 Power adaptor 2 150Ã-2=300 Total 3420

Table 3(design cost)

## Remake design

Figure 14(remake design)

Compare the cost

 Item name Previous cost (Rs) New cost(Rs) 2 pin AND gate IC 1Ã-120 = 120 1Ã-120 = 120 3 pin AND gate IC 1Ã-120 = 120 0 XOR gate IC 1Ã- 40 = 40 0 D type FF IC 1Ã-100 = 100 1Ã-100 = 100 Decoder IC 0 1Ã-100 = 100 NOT gate IC 1Ã- 40 = 40 2Ã- 40 = 40 OR gate Ic 1Ã- 40 = 40 1Ã- 40 = 40 total 460 400 Table 4(compare table)
• In new design cost is less than old design

Reference

ïƒ˜ï€ Mano M.M,Michael D.C. (2008).Digital Design.New Delhi:PHI.

ïƒ˜ï€ Floyd,L.(2011).Digital Fundamentals.10th ed.India:Pearson. p271- 287.

ïƒ˜ï€ http://www.topssrilanka.com/article24948-new-traffic-ligth-system-atbambalapitiya.html.Lasr

ïƒ˜ï€ http://www.sundayobserver.lk/2012/06/03/imp01.asp

## Cite This Work

To export a reference to this article please select a referencing stye below:

View all

## DMCA / Removal Request

If you are the original writer of this essay and no longer wish to have your work published on UKEssays.com then please:

Related Services

Our academic writing and marking services can help you!

Prices from

QAR553

Approximate costs for:

• Undergraduate 2:2
• 1000 words
• 7 day delivery

Humanity University

Dedicated to your worth and value as a human being!

Related Lectures

Study for free with our range of university lectures!

Freelance Writing Jobs

Looking for a flexible role?
Do you have a 2:1 degree or higher?

Study Resources

Free resources to assist you with your university studies!