University of Nueva Caceres

College of Engineering and Architecture

City of Naga

MINI-CONVEYOR SYSTEM WITH DISPLAY COUNTER

A Project

Submitted in Partial Fulfillment of the Requirements

For Industrial Electronics Subject

Submitted By:

Submitted To:

MARCH 2012

CONTENTS

I. INTRODUCTION

II. PROBLEM STATEMENT

III. DESIGN DESCRIPTION

IV. COMPUTATIONS

V. SCHEMATIC DIAGRAM

VI. SIMULATION

VII. COMPONENT AND PCB LAYOUT

VIII. ACTUAL PHOTOS

IX. BILL OF MATERIALS

X. DATASHEETS

XI. GRADING SHEET

I. INTRODUCTION

A conveyor system is a device which is used to move bulky materials from one

place to another. Conveyors are really important in transporting heavy and large materials

and packages. They are very effective and efficient which makes them usable in nearly all

industries that require material handling. There are several types of conveying systems

which suit the different requirements of various industries.

Conveyors are used internationally and are a common requirement in just about

every industry, including the automotive, agricultural, computer, electronics, food

processing, aerospace, pharmaceuticals, chemical, bottling and canning, print finishing

and packaging.

The main purposes of conveyors are to less the human effort and make the work

fast and efficient. Although a wide variety of materials can be conveyed, some of the most

common include food items such as beans and nuts, bottles and cans, automotive

components, scrap metal, pills and powders, wood and furniture and grain and animal

feed.

II. PROBLEM STATEMENT

What kind of motor to use to drive the rollers of the conveyor belt?

What is the easiest way and the most practical material to be used in creating the

skeleton of the conveyor: wood, plastic, glass or metal?

How will the rotor be connected to the roller(s) of conveyor?

What sensor to use to detect and count the object passing in the conveyor’s sensor?

What is the easier way of creating a simple counter: PIC microcontrollers or simple IC’s

like decade counter?

How the debounce will be eliminated coming from the sensor?

III. DESIGN DESCRIPTION

Using a high-torque DC motor to rotate the rollers of the conveyor, the object

will move together with the conveyor belt until it reaches the sensor which is composed

of a Light Amplification by Stimulated Emission of Radiation (LASER) beam and a Light-

Dependent Resistor (LDR). When an object passes through the beam, the LDR voltage drop

goes high with higher resistance causing an lower voltage input to the 555 timer that will

result in a a LOGIC HIGH output. The output of the 555 timer is connected to the clock of

the decade counter, thus, the logic high input will trigger the counter to count or

increment by 1. CD4026 decade counter has a binary output and is directly connected to

the 7-segment display.

For every object that will pass through the beam, the counter will increment by 1

until it reaches 99, and it will return to 00 and count again.

IV. COMPUTATIONS

Using it as a driver and as a debounce circuit,

555 acts as an electronic switch which turns

on and off depending upon the input voltage.

In our case, the input voltage will be

controlled by the LDR. The circuit has an

inverting Schmitt trigger action. The

'inverting' part of this description means that

when Vin is LOW, the output is HIGH, and

when Vin is HIGH, the output is LOW.

In a Schmitt trigger circuit there are two different switching thresholds. If Vin is slowly

increased starting from 0 V, the output voltage snaps from HIGH to LOW when Vin reaches a level

equal to 2/3 of the power supply voltage. Once this level has been exceeded, decreasing Vin does

not affect the output until Vin drops below 1/3 of the power supply voltage. (If an input change in

one direction produces a different result from a change in the opposite direction, the circuit is said

to show hysteresis.)

When the LASER is not blocked by any object, the light coming from it causes the

LDR to drop its resistance to 400Ω. So finding the voltage across the resistor R1:

k

kVVR

1400

)1(51

VVR 571428571.31

With 3.57V input at pin 2 and pin 6, the output will be LOW.

When an object block the light from the LASER, the resistance of LDR goes as

high as 38kΩ resulting to:

kk

kVVR

138

)1(51

VVR 1282051282.01

With less than 1V input to the 555, its output will be HIGH.

V. SCHEMATIC DIAGRAM

VI. SIMULATION

VII. COMPONENT AND PCB LAYOUT

VIII. ACTUAL PHOTOS

IX. BILL OF MATERIALS

QUANTITY DESCRIPTION UNIT PRICE SUBTOTAL

1 Conveyor Hardware P 450.00 1 GA680 DC Motor P 385.00 385.00 1 24V-0-24V Transformer 1 KIA7805 40.00 40.00 1 NE555 30.00 30.00 2 CD4026 150.00 300.00 2 7-Segment Display (CC) 30.00 60.00 1 LDR 5.00 5.00 1 LASER 8.00 8.50 1 24-pin IC Holder 4.00 4.00 1 1 kΩ 1/2W Resistor 0.75 0.75 1 10 uF Ceramic Capacitor 2.50 2.50 1 10 nF Ceramic Capacitor 1.00 1.00 1 SPST Switch 1 Power Cord 1 Fuse 1A 1 Fuse Holder 2 Rubber Strip (Big) 25.00 50.00 1 Rubber Strip (Small) 7.00 7.00 1 Copper Clad 22.00 22.00 1 Ferric Chloride 35.00 35.00 2 Super Glue 10.00 20.00 2 Acrylic Paint (Red) 25.00 50.00 1 ft. Hollow Metal Tube 10.00 10.00 2 m. Stranded Wire 3.50 7.00

TOTAL: P 1487.75

X. DATASHEETS

XI. GRADING SHEET

NAME OF PROJECT: MINI-CONVEYOR SYSTEM WITH DISPLAY COUNTER

SUBJECT: Industrial Electronics SCHOOL YEAR: 2011-2012

NAME: DATE SUBMITTED: __________________

CRITERIA PERCENTAGE GRADE REMARKS

LAYOUT 10%

DOCUMENTATION 10%

DESIGN 30%

FUNCTIONALITY 50%

TOTAL 100%