1.1 Introduction
A timer is a device used to measure the amount of time taken by a process or activities. It can also be defined as a device that starts or stops a machine working at a particular time (Oxford Dictionary, 2017). A timer for processing data blocks is proposed for a receiver of a mobile communications system (Yi, 2014). A system for automatically recording an event transmitted over a network is provided. A network client is programmed to automatically access a network server at first specify time, download the data from the server to specified destination or file, stop download at a specified time, and automatically disconnect from the network server (Lowell 2000).
As a prelude to other parts of this study, this chapter will discuss the background upon which this study was initiated, the statement of problems that led to this study, the Aim and Objectives of the study. Others are Significance of the study, Scope of work, Research hypothesis and questions, Limitations of the Study and Definition of technical terms.
1.2 Background of Study
The world is concerned with conserving electric power and the fuels that generate electricity, there is a growing need for the conscientious homeowner to keep an eye on and minimize their power usage. Standby power is loosely defined as the “electricalpowerconsumed by appliances while they are switched off (but are designed to draw some power) or in a standby mode. This only occurs because some devices claimed to be “s different state from switching off at the pl off at the power point is effective enough to control the vampire power, there is no need to disconnect all the devices from the power point.
Some devices utilize vampire power in a useful manner to provide persistence features such as maintaining clock settings between active sessions, convenience features such as powering the necessary hardware to respond to remote controls, and to eliminate long initialization times by keeping the hardware in a semi-powered state. Other devices have no beneficial use of vampire power, such as a powered but disconnected mobile device charger or an uninterruptible power supply (UPS) with no active system connected. With advancement of technology, things are becoming simpler and easier for us. Automation is the use of control systems and information technologies to reduce the need for human work in the production of goods and services.
The case of the MICROCONTROLLER TIMER SOCKET OUTLET helps in conserving the vampire power. Electrical and electronic appliances are connected to the socket outlet and programmed to be in power for a specific dur way in conserving energy as the device(s) is/are disconnected after the specified duration. It is very useful in cases whereby the user has to keep in touch of what he or she had connected earlier and due to the multitasking nature of human beings, we tend to forget what had been connected to attend to other things in the household or wherever we find ourselves.
Therefore, in Nigeria where the research was carried out, the activities that was conducted is to Design and Construct a Microcontroller Timer Socket Outlet.
1.3 Statement of Problems
Investigation revealed that Electric fire outbreaks occur frequently throughout the world, causing injury, claiming lives, and resulting in large losses of property (U.S. DH S, 2014). The residential electric fire outbreaks are mostly caused by faulty socket, electronics equipment or electrical appliances failure (Adekunle et al., 2016). It was observed that some of the failures are as a result of leaving or forgetting those appliances connected to a socket outlet for a long time (SCDF, 2016).
The 1 to 100 minute socket outlet timer is introduced to prevent and reduce the above problem by allowing the user to always select appropriate time before connecting equipment or an electrical appliance to the socket in order to turn them OFF automatically after a selected period.
1.4 Aim and Objectives of Study
The aim of the study is to Design and Construct an automatic socket outlet with an operational timer incorporated into it using a microcontroller. In achieving this aim, the following specific objectives were laid out as follows:
- To conserve electrical power domestically.
- To reduce and subsequently prevent electrical hazards in the home front.
- To control the use of electrical power domestically.
- To reduce electricity bills through the conservation and control of electrical power.
1.5 Significance of Study
This study will be of immense benefit to PHCN Company and other researchers who intend to know more on this study and can also be used by non-researchers to build more on their research work. This study contributes to knowledge and could serve as a guide for other study.
1.6 Scope of Study
The scope of the research is focused on Design and Construction of Microcontroller Timer Socket Outlet.
1.7 Limitations of the Study
During the course of this study, many things militated against its completion, some of which are:
- Time Constraint: The time frame given to accomplish this project was very short due to school academic calendar and it was carried out under pressure which made the researcher not to implement some necessary features.
- Research material: availability of research material is a major setback to the scope of the study.
- Frequent power failure: This made the researcher append more money on fuel to ensure sustainable power.
- Financial Constraint: Insufficient fund tends to impede the efficiency of the researcher in sourcing for the relevant materials, literature or information and in the process of data collection (internet, questionnaire and interview).
1.8 Project Motivation
Since the advent of socket outlet manufacturing in developing countries like Nigeria, solution has been found for power conservation or regulation. There is yet to be an effective socket outlet for timing domestic socket outlets. The failure to have an operational timer for the socket outlets has caused a lot of electrical hazards. This has claimed lives and properties of many people. The user often forgets to look after what he/she had connected and due to incessant power outages, he/she often forgets to switch off appliances earlier connected to power when leaving his/her home or due to carelessness of the user. Due to this negligence, the connected appliances continue to build up, when power is restored, even after completing their purpose of connection and when it gets beyond control, it damages the appliances. Repeated occurrences of these hazards have led to the loss of valuable things worth millions of naira.
However, with the help of a timer socket outlet, an effective solution is provided to these problems. An effective control timer for the socket outlet makes it safer and easier to use and also helps to reduce hazard rate. The use of a microcontroller comes to play in this motivation. Every microcontroller has a timer unit inside. A timer is nothing more than a time counting device fabricated inside the microcontroller unit. A wide range of practical applications require a timer in action. For example, we need to turn a motor ON for 5 minutes and then turn it OFF, how will we do that? A timer inside a microcontroller unit aids us in implementing this perfectly.
1.9 Methodology
The circuit employs the use of various electrical and electronic components like resistors, capacitors, light emitting diode (LED), switches, piezoelectric buzzer, 13-amp socket outlet, jumper wires, 7-segment display, battery, relay, Vero board and most importantly, the Peripheral Interface Microcontroller 16F877 microcontroller (PIC 16F877).
The microcontroller is programmed using “software the” Mikro C. It is programmed to communicate with all the other components on the board.
The switches are used to input instructions into the microcontroller. The instructions are basically the SET TIME, START, RESET and STOP.
The SET TIME instructions are displayed on the 7-segment display.
The START button signifies the beginning of the entire timing process.
If a wrong time is set in, the RESET button helps to restore it to default.
The STOP button helps to stop the timing process, this is necessary as there could be a change of mind after the process has started.
The battery serves as a temporary memory holder. If during the process, there is power outage and the set instruction has not been reached, it will help the circuit start from where it stops when power is restored. For example, a 12,000-litre reservoir fills to the brim in 30minutes, the set instruction will be 30minutes and if there is power outage after the 23rd minute, the battery helps to continue from where it stopped (23rd minute) to the 30th minute. However, a major limitation to this is in the use of a boiling ring, or for the purpose of boiling. If experimentally, pure water boils in exactly 10mins, and power outage occurs in the 7th minute for as long as 30minutes, when power is restored, the water cannot boil in 3minutes again. So this is where the STOP button comes to play.
The buzzer and the LED serve as audio and visual indicators respectively. They indicate the completion of the timing process. They indicate that the process was completed according to the set instruction. After completion, the circuit automatically shuts the relay off which stops the supply of power to the circuit thereby conserving power.
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