ET1011 INTRODUCTION TO ENGINEERING II

IE II Project – Moving Car Transit

INTRODUCTION

The purpose of this project is to develop a car that can move forward from Station 1 to an assigned Station, reverse automatically and stop after hitting an emergency switch (micro switch) in the forward and reverse direction.

The car must be able to detect and count gantries as it moves forward.  Once the car has gone under a predetermined number of gantries, it will reverse.

The overall specification of your designed car should not exceed 12cm (W), 17cm (L) and 15cm (H).

Each Station shall have an inverted U-shaped piece of Acrylic material which positions at a height of 15cm. The intention is to make the light dimmer at these stations as the car passes through them and interrupt its light dependent resistor.

This project is to be done in groups of 3 to 4 students and a maximum of 6 teams per class.

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6          Count Limiting Circuit (Student Board)

The Count Limiting Circuit is to be designed and built by each project group. The Circuit should be able to receive the Q₀ – Q₃ feedback signals, decode them, compare with the reference signal (ie the assigned station as given by your lecturer) and produce the appropriate output signals ie the Up or Down signal to the Counter and Display Circuit and Forward or Reverse signal to the Motion Control Circuit.

Design your circuit based on the loop that your lecturer assigned to your team. Simplify your circuit and try to achieve with minimum possible number of components.

You may use the ICs listed below and they are available in the laboratory.

1) 74LS32 OR gate

2) 74LS08 AND gate

3) 74LS04 NOT gate

4) 74LS02 NOR gate

5) 74LS00 NAND gate

6) 74LS74 D flip flop

7) 2N3904 NPN transistor

Note: The power supply for this project is 9V battery for the electronic circuitry and 3V battery for the motor.

Component List (component required to build a adjustable count limiting circuit )
1. IC 7474
2.  Resistor
3. Pins
4. Stripboard
5. 7400
6. 7432
7. 4way DIL switch

Plan

* CPU and CPD get from seven segment display board
* Clock get from ldr board
* Reverse get from motor board