Abstract

An automatic regulator suitable for water level sensing and control bought for the purpose of this study was realized using the MC14066 integrated circuit. This enabled the entire circuit to function as a threshold detector; thus working as an ON/OFF switch. The water level sensor was tested in real time application by using it to control the level of water in a tank fed by a single phase 0.5 HP AC pump. The installation  performance results indicated that the device  is quite simple for the desired operation, since it maintained the set maximum and minimum levels of 50 litres and 10 litres respectively, by switching the pump on or off as required.

Keywords:     electronic circuitry, water level, integrated circuit, control, regulator

1.0                                                         INTRODUCTION

1.1      BACKGROUND OF THE STUDY

The process requirement in many industries, farms, hostels, hotels etc includes an overhead tank for water, which is usually fed through an electric pump that is switched off when the tank is filled up, and on when it becomes empty. As such, the most common way of knowing when the tank is filled is by observing when it  overflows the brim. Depending on the type of liquid being handled, the overfilling of such a tank could lead to heavy material losses ranging in the order of thousands of Naira per week. These losses can be prevented if the tank is regulated automatically by incorporating a feed-back control mechanism, which would be capable of tripping the pump on or off as required. Although pumps equipped with variable speed motors could be more efficient than on/off mechanisms, the former are expensive to procure and maintain, especially for small and medium enterprises. Furthermore, commercially available water level sensors are expensive being imported into the country and as such cannot be deployed in every household.

Control systems are classified as open loop or closed loop. In open loop systems a command is given to a system and it is assumed the system performs properly. A closed loop system, on the other hand, compares the result or output of the system to a desired output and takes appropriate corrective actions. Closed loop systems therefore, generally exhibit more accurate performance but cost more and tend to be more unstable.

Control systems are also classified as sequential, continuous or discrete. Sequential control systems cause a machine or system to go through a set series of operations. For instance, a sequential control system may remove the milking ma- chine when a cow is finished in a milking parlour, open the gate to let the cow out, close the gate after the cow is out and then let in the next cow. Complex sequential control  systems  can be analysed with Boolean algebra, truth tables, flowcharts or state diagrams. Contemporary sequential control systems may use programmable logic controllers (PLCs) to allow the sequence of control to be modified in software rather than requiring hardware or connection changes. Continuous control systems are the usual subject of control theory analysis [1, 2, 3].   Such systems are physical systems in which the input-output behaviour of the system can be described by ordinary differential equations in time. Many of the components have a relationship that can be modelled as a constitutive equation of the relationship of a through variable to an across variable. For instance, the current through an electrical component or the fluid flow through an orifice can be related to the voltage across or the pressure across that component.

This paper, therefore, dwells on the installation of a simple but effective feedback regulator for use in water level sensing and control.

1.2                                                 PROBLEM STATEMENT

Looking at the water level controller sold in market today one will realize that it is difficult to detect how the installation of the device will be carried out. This study was carried out to make a clarification and provide an easy way of installing a water level controller.

1.3                                    AIM AND OBJECTIVES OF THE STUDY

The main aim of this study is to carry out the installation of an already built water level controller. The objectives of the work are:

1. To install an automatic switching circuit that can be used to control an AC water pump
2. To make a cheap but efficient water level controller

• To automatically control the flow of water into the tank

1.4                                                   SCOPE OF THE STUDY

The scope of this study covers installing an automatic water level controller that was bought in an electronics store. The installation was carried out by observing the terminals labeled according to the producer’s directives from the user manual.

1.5                                           SIGNIFICANCE OF THE STUDY

This study shall serve as means of making the installation of the water level controller installation easier for all readers of this work.

It will also serve as a means of becoming familiar with water level controller accessories.

1.6                                            APPLICATION OF THE STUDY

This study will be useful to the following categories of people:

1. All electrical and electronics students
2. Electronics hobbyist