Construction Of Blender Control Circuit With Security Lock And Mini Amplifier Circuit

ABSTRACT

This work is on a blender control circuit with security lock and mini amplifier circuit. The control circuit was designed and constructed which uses two 555 timers, one is connected in the monostable mode which determines the overall period of operation, while the other is connected in a stable mode which determines the intermittent operation of the blender. This saves the operator from the rigor of continuo’s switching ‘ON’ and ‘OFF’ until processing is completed. Transistor amplified is used to supply the sufficient current Ic to energize the 12 volts relay. The duty cycle for the intermittent operation of this device is 66.7% compared with that of manual operation that may vary from one individual to another. The operation is automatic; hence the device goes a long way in protecting the blender motor.

Keywords: 555 timers, intermittent operation, blending, electric motor, traditional methods.

TABLE OF CONTENTS

 TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWLEDGEMENT

ABSTRACT

TABLE OF CONTENT

CHAPTER ONE

• INTRODUCTION
• BACKGROUND OF THE STUDY
• PROBLEM STATEMENT
• AIM/OBJECTIVE OF THE PROJECT
• SCOPE OF THE PROJECT
• SIGNIFICANCE OF THE PROJECT
• PROJECT ORGANISATION

CHAPTER TWO

2.0     LITERATURE REVIEW

2.1     REVIEW OF THE STUDY

2.2     HISTORICAL BACKGROUND OF THE PROJECT

2.3      REVIEW OF DIFFERENT TYPES OF BLENDER

2.4     TECHNOLOGICAL DEVELOPMENT OF BLENDER

CHAPTER THREE

3.0     DESIGN METHODOLOGY

3.1      SYSTEM BLOCK DIAGRAM

3.2      SYSTEM CIRCUIT DIAGRAM

3.3      POWER SUPPLY UNIT

3.4      CIRCUIT DESIGN ANALYSIS AND CALCULATIONS

CHAPTER FOUR

RESULT ANALYSIS

4.1      CONSTRUCTION PROCEDURE AND TESTING

4.2      ASSEMBLING OF SECTIONS

4.3     PERFORMANCE ANALYSIS

CHAPTER FIVE

5.1      CONCLUSION

5.2      REFERENCES

CHAPTER ONE

1.0                                          INTRODUCTION

1.1                            BACKGROUND OF THE STUDY

As a result of the advancement in technology, electric blender had been widely used for commercial and domestic purposes. The electric blender is gradually replacing the traditional method of blending or using grinding stone, mental and pestle, knives or grater.

Although the blender used based on it comfort and speed, most of its users may not understand it mode of operation and control. The machine, which has an intermittent duty cycle, need not be “NO” for too long before it is put “OFF”. It is a machine that required the operation of being “NO” and “OFF” positions at intervals until the entire blending process is completed. The motive power for an electric blender machine is provided by an induction motor. The repetitive working periods are too short to allow the motor to cool down to the ambient temperature. This intermittent duty cycle is accomplished by the operator switching “NO” and “OFF” the power of the machine.

The indispensability of safety for the machine and its operator, necessitated moves to control the blending process of the machine in order to avoid excessive sparks at the commentator and overheating of the armature or stator winding due to human error. This necessitated the need for the design and development of a control circuit, which provides automatically the intermittent operation. Fig, 2, shows the complete circuit, diagram of the automatic control circuit of the electric blender, the blending process commenced by filling the jar with soft food items, the processing time is selected by switching the knob sw to R₁, R₂, or R₃ in the (monostable  multivibrator) control circuit. The supply cord is then connected to the supply, the blender will only commence action when the push button in fig. (1) Has been pressed, at this stage the relay, which is energized by sufficient current from the transistor amplified. The relay, which is connected is normally open will close contact and the blender operate for the time when an stable muitibrator will be high. When the output of the stable multivibrator becomes low the relay will open its contact hereby isolating the blender from power supply. As a result of the free running action of an stable multivibrator, the relay will continue to make and break contact. These repeated actions of the relay connect and disconnects the blender from the power supply until the time setting of R₁, R₂, or R₃ expires.

1.2                                   PROBLEM STATEMENT

Blender was invented to replace the traditional method of grinding. The traditional methods require greater human power and attention. It is time consuming and every stressful. The advent of electricity and electric motor has revolutionized blending technology. The blending machine greatly reduces the risks of injuries and muscle cramps and tears involved with the crude system of grinding using mortal, stone and knives. It is true that blending machine makes use of electricity which makes it semi – automatic yet it still involve human operation and attention. To solve this problem, a control circuit with security lock and mini amplifier circuit were built. This saves the operator from the rigor of continuo’s switching ‘ON’ and ‘OFF’ until processing is completed.

1.3                     AIM AND OBJECTIVES OF THE STUDY

The main aim of this work is to build a blender control circuit with security lock and mini amplifier circuit. The objectives of building this device are:

1. To make a blender fully automatic
2. To save time

• To eliminate human labour

1. To build the circuit that small in size, high in safety performance and easy to operate.

1.4                                    SCOPE OF THE STUDY

The scope of this work focused on building a circuit that control the ON, OFF, and the speed of a blender. The circuit uses two 555 timers, one is connected in the monostable mode which determines the overall period of operation, while the other is connected in a stable mode which determines the intermittent operation of the blender. A transistor is used as a mini amplifier circuit. Transistor amplified is used to supply the sufficient current Ic to energize the 12 volts relay

1.5                                           SIGNIFICANCE OF THE STUDY

This work will be of great benefit to the student involved in that it will help him to understand fully how a blender is made as well as the operation of an automatic blender.

To the producer, this study will exposed them to expand their knowledge which can lead to produces diversity of blenders with different functions and features.

1.6                                   PROJECT ORGANISATION

The work is organized as follows: chapter one discuss the introductory part of the work,   chapter two presents the literature review of the study, chapter three describes the methods applied, chapter four discusses the results of the work, chapter five summarizes the research outcomes and the recommendations.