Saturday, January 30, 2010

Construction of a multi switch Musical doorbell with indicators

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CHAPTER ONE
1.0 INTRODUCTION
1.1 Introduction:
Modern doorbell, comes in two basic types, the simple electrical ding-dong (chims) or the sophisticated microprocessor – controlled multi-tune/switch (Rule Britannia etc) types. In either case, you pay your money and have to accept the sounds that the manufacturers have pre-programmed into your particular device. If you ever get tired of your bells limited range of sounds, you have little or no option but to buy a new unit.
We have decided to overcome this by designing a multi-switch musical doorbell with indicator as a project that will aid the owner to self-program the project to play any designed (but brief) melody. The essence of this project is that it is simple, and it is devoid of hard to get micros, PROMS, double sided PCBs etc yet gives an entertaining performance.
This doorbell is designed with six switches made up of a particular melody or tones. The melody continues as long as possible until the reset button is briefly operated.
A feature of this doorbell is that it incorporates a bistable electronic switch that connects power to the unit in such a way that it consumes virtually zero power when in standby mode, whenever the bell-button is pressed, the bistable connects power to the unit. For the duration of the tone play and automatically disconnects the power when the resets button is activated. This facility ensures long battery life.
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1.2 OBJECTIVES
The major purpose of a multi-switched musical doorbell with indicators which composes of different switches and a tone attached to it, helps in providing or creating of awareness to the occupant or residents of buildings, that their attention is needed at their door post. It is an electronic informer of building occupants.
And it also helps the owner or occupants of a building who have a multi-switch musical doorbell attached to their houses, for the easy recognition of the presence of a visitor in his or her house. The advantages of a musical doorbell are as follows:
- It allows an easy positioning of switch at different door steps of buildings i.e. for buildings that have more than one entrance.
- It goes beyond the reach of an ordinary knocking with bare-hands and also last as long as possible.
CHAPTER TWO
2.0 CIRCUIT COMPONENTS
2.1 List of Circuit Components
The following are the list of components that make up a multi-switch musical doorbell with indicators.
(a) Resistor
(b) Light Emitting Diode (LED)
(c) Capacitor 0.1μf
(d) Integrated Circuit (IC) CD4042B, CD4002
(e) Transistor SL100B
(f) Push to on switches
(g) B21 Musical Buzzer (6 – 12v dc)
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2.2 INTEGRATED CIRCUIT
An integrated circuit (IC) is a tiny piece of semi-conducting material into which a very complex circuit is cut. It is a complete circuit manufactured in a single package i.e. many circuit contain in one package. They are different types of integrated circuits (ICs). On like in the hybrid IC, separate components ends / or circuit are attached to a ceramic substance and interconnected.
In monolithic ICs, all the components are manufactured into or on top of a single chip of silicon. They are formed by selective diffusion of the appropriate type of impurity into a layer of semiconductor. The bipolar junction transistors and the MOS, ICs are based on insulated gate field effect transistor. Both are lythic circuits.
They are several types of IC in use today. Those used for the surface mount technology are the plastic guard flat package. The flat pack (glass/metal). Other ICs used with sockets are the pin grid array package (PGA) and the leadless package.
Those ICs like the TO-3, TO-220 packs and TO-066 are used for voltage regulators, others are the TO-5 package, which are available with 8,10, and 12 pins. (TO-39, TO-96, TO-99 and TO-100). The dual in like package (DIP) is popular. It may have 14 or 16 pins. The main – DIP is a shorter version of the dual in line package, it has 8 pins.
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CIRCUIT SYMBOL
The main IC used for this project work are the CD4042B and CD4002B types.
2.3 RESISTOR
A resistor is an electrical component that offers opposition to the flow of current in circuit. They are described by stating their resistance in ohms along with their safe power dissipating ability in watt. Resistors may be classified avoiding their constitution which may be composition film types or wire wound, further classification may be made according to whether the resistor is fixed or variable. Variable may be further classified as variable – slide rheostat and potential types.
The resistance value and tolerance are indicated on the resistor body by means of colour code bond (especially in carbon filled type). In practical, factors to be considered in the choice of a resistor for a given purpose are:-
i. Required resistance
ii. Power to be dissipated (I2R) or current to be carried.
iii. Effect of residual (inherent) inductance and capacitances.
iv. Allowable tolerable (deviation from labelled ‘normal’ resistance) value.
v. Effect of variation of resistance with temperature
Red
Red
Red
Gold
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2.4 LIGHT EMITTING DIODE (LED)
It’s a special P-N Junction diode that emits light when forward-biased. When a normal diode is forward-biased, current flows which cause a voltage drop of approximately 0.7 volts in a silicon diode. The voltage drop times the magnitude of current flow results in power dissipation at the junction. In a normal diode, this power is dissipated in the form of heat energy. However, in the case of a light emitting diode, this power is dissipated in the form of light.
There are two main differences between normal diodes and LED. One difference is that LED’s are made from gallium arsenide (Ga/As). Gallium arsenide phosphide (Ga,As,P) or gallium phosphate (Ga,P) diodes manufactured from these elements radiates visible light energy when forward-biased. The second difference is that LEDs are so designed as to have a window over the unction so that light energy can be seen.
The different wavelengths of light emitted by the above LED are as under:
i) Ga,AS - 8800A0 infrared radiation
ii) Ga,P - 5500A0 (green) or 7000A (red)
iii) Ga,As,P - 5800A0 (amber) or 6600A (red)
LED are commonly used for indicator lamps and read out displays device using LED from consumer appliances to scientific apparatus. A very common type of display device using LED is the seven segment display shown below
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SEVEN SEGMENT DISPLAY
Combination of these segments can form the ten decimal digits. Infrared emitting LEDs are used in optical coupling applications often in conjunction with fibre optics.
Light Energy
P
N
SYMBOL OF DIODE
LED
2.5 CAPACITOR
A capacitor essentially consists of two conducting surfaces separated by a layer of an insulating medium called dielectric. The
conducting surfaces may be in the form of either circular (or rectangular) plates or of spherical or cylindrical shape. The purpose of a capacitor is to store electrical energy by electrostatic stress in the dielectric.
Therefore, the electrolytic capacitors are either the wet type or dry type. The wet type consists of an aluminum anode which is centrally mounted in a metal cylinder filled with an electrolytic solution usually ammonium borate which acts as a cathode. Two connections, one
+
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from the anode and the other from the cathode are brought out. When current is passed between the anode and cathode, a very thin film of aluminum oxide (Al2, 03) is formed on the anode surface. This film has insulating properties and the anode – cathode combination, thereafter becomes a capacitor of very large capacitance because dielectric film is extremely thin. For successful operation, such capacitors must always be used with proper polarity. The dry type capacitor consists of positive and negative electrodes of aluminum foil which are separated from each other by a porous paper or guaze saturated with either a very viscous liquid or paste containing the electrolyte. The whole arrangement is formed into a roll and housed in a waxed cardboard tube. Due to their high capacitance, such capacitors are used generally in smoothing circuit in radio work.
Capacitor Symbol
2.6 TRANSISTOR
Basically, it consists of two back-to-back P-N junctions manufactured in a single piece of a semi-conductor crystal. These two junctions give rise to three regions called emitter, base, and collector. A junction transistor is simply a sandwich of one type of semiconductor material between two layers of the other type, a layer of N-type material sandwich between two layers of P-type material, it is described as PNP transistor.
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Structure
C E
E C
B
B SYMBOL
The NPN transistor consists of P-Type material sandwich between two layers of N-type material. The emitter, base and collector are provided with terminals which are labeled as E, B and C. the two junctions are: emitter base (E/B) Junction and Collector Base (C/B) junction.
Structure
E C
B
The arrowhead of transistor is always at the emitter (not at the collector) and in each case, its direction indicates the convectional flow of currents. For a PNP transistor, the arrowhead points from emitter to base meaning that emitter is positive with respect to base (and also with respect to collector). For an NPN transistor, it points from base to emitter meaning that base (and collector as well) is positive with respect to emitter.
EMITTER
It forms the left hand section or region of the transistor, it is more heavily doped than any of the other regions because it’s main
P
N
P
N
P
N
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function to supply majority charge carriers (either electrons or holes) to the base.
BASE
It forms the middle section of the transistor. It is very thin (10-6m) as compared to either the emitter or collector and is very lightly doped.
COLLECTOR
It forms the right hand side section or region of the transistor and its main function is (as indicated by its name) to collect majority charge carriers coming from the emitter and passing through the base.
In most transistors, collector region is made physically larger than the emitter region because it has to dissipate much greater power, it may be noted, in passing, that transistors are made by growing, allowing or diffusing processes.
CHARACTERISTICS
These are the curves which represent relationships between different dc currents and voltages of a transistor. These are helpful in studying the operations of a transistor when connected in a circuit. The three important characteristics of a transistor are:
1. Input characteristics
2. Output characteristics
3. Constant-current transfer characteristic.
2.7 MUSICAL BUZZER (6 – 12V DC)
Musical buzzer in these project helps in bringing out quality output from the input when the various switches are operated, and these output comes in the form of melody. The multi-switched musical
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doorbell with indicators makes use of a 6 – 12v dc. A musical buzzer possesses some similar characteristic related to an ordinary radio speaker.
+
_
Circuit Symbol
2.8 PUSH – TO – ON – SWITCH
The type of switch used for the proper execution of this project is the push-to-on switches which are readily available, on like every other electronic switches used in some electronic components, and its operation is based on the push to on mode for activating the system, until the reset button is pressed.
2.9 VERO BOARD:
Vero board is a matrix board with continuous copper ship attached to one side by adhesives. The copper strip link together rows of holes so that connections can be made between components inserted into holes on a particular row. The circuit components are held permanently on the vero board with the use of a soldering iron and lead.
CHAPTER THREE
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3.0 CONSTRUCTION OF MULTI-SWITCH MUSICAL DOORBELL WITH INDICATORS
3.1 BLOCK DIAGRAM
C Buzzer
3.2 SCHEMATIC DIAGRAM
RESET
SWITCH S5
S2 – S4 SWITCHES
R6 – R9 RESISTORS
DC POWER SUPPLY UNIT +9V
R1 – R5
RESISTORS
LEDS
IC1
N1&N2
IC2(GATES)
TRANSISTOR
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3.3 HOW IT WORKS
In the circuit of a multi-switch input musical doorbell, the circuit is built around the popular and less expensive guard D-latch CD4042B (IC). When switch S6 is pushed to ‘on’ condition, the circuit gets +9v and the four data inputs (D1 through D4) of IC1 are in low state because these are tied to ground via resistors R1 through R4. Polarity input (POL) Pin 6 of IC1 is also pulled down by resistor R5. Clock input (Pin5) of the guard D-latch is wired in normally low mode
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and hence all the four outputs (Q0 through Q3) have the same states as their corresponding data inputs. As a result, LED1 through LED4 are in off condition.
There are four switches fitted at four different doors/gates outside the home and a monitoring panel in the common room of the home. If any switch is pressed by a visitor (for example switch S1 at door 1), pin2 and 4 of IC1 go high. Simultaneously, pin 3 to IC1 (Qo output) goes low and LED1 starts glowing to indicates that switch S1 is pressed by someone.
Next output pin 13 of the dual 4-input NOR gate (IC2, here wired as a single 4-input OR gate) goes high to forward bias buzzer driver transistor T1 via resistor R10.
The final result is a soft and pleasing musical bell, which lasts until reset switch S5 is pressed by the owner. For this latching arrangement, output pin 13 of IC2 from the NOR gate is fed back to the clock input of IC1.
CHAPTER FOUR
4.0 TOOLS AND CONSTRUCTION TECHNIQUES
4.1 CONSTRUCTION TECHNIQUES
The construction of this project is a simple but, lightly complicated and technical one. In the construction of the main circuit board the following steps were followed.
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- The strip (vero) board was marked with strips running from left to right.
- The components were assembled taking care to fix in the transistor, diode etc. the right way round. The integrated circuits (ICs) were mounted and positioned in such away that, the current pins stay in the correct holes.
- Correct soldering of components was done to ensure good electrical and mechanical constant.
- Connectors were often used to carry/connect terminals from the strip board to the external components like the switch, LED etc.
- Finally, the strip board was fixed inside a case, care was taken to ensure that the board was properly fixed into the base of the case and that no metallic object was bringing any of the strip board lines.
The container was designed to ensure that the strip board and other components sit inside comfortably, and that no element of the case was disturbing the comfort of the others.
The case material was cut out, designed and the finished was polished before the case design are
- The size
- The shape
- The accessibility to the internal component in time maintenance.
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Finally, the cover of the case was screwed in, to give a complete and perfect finished job.
4.2 TOOLS/MATERIALS USED FOR CONSTRUCTION
In the course of constructing this project, various tools/material were used to ensure proper connection of wires and fillings of components at their appropriate positions in order to achieve a successful result. Base on this, the following tool/materials were used:
- Side Cutter:- This was used for cutting off the remaining of the soldering.
- Long Nose Pliers: It was used for picking materials from places where bear hand cannot be able to reach. It was also used for holding components before soldering thereby acting as temporary heat sink to such components.
- Solder: This is a soft silver metal made of two materials, an allow of tin and lead. There are three main grades of solder, 40-60 grades, 50-50 grades. The first figure is the percentage of tin while the second is the percentage of lead. The 60-40 grades are popularly employed for electronic work but more expensive.
- Combination Pliers: This was used for griping and cutting of wires with other cylindrical material and also for loosening nuts.
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- Soldering Iron: In the construction of this project, two types of soldering irons were used. These are: the electric iron and the fire soldering iron. The electric type has a cord through which electric passes into it to be heated up while the fire type can be heated by merely placing it on the fire.
4.3 TESTING
After the construction, the system was tested and there rang almost to the number of time expected, so for that reason some components in the circuit were adjusted while some were replaced to improve the system performance. The power supply unit was tested again for over two hours to ascertain it normal ringing level of the various bell controlled by the switches.
CHAPTER FIVE
5.0 SUMMARY, CONCLUSION AND RECOMMENDATION
5.1 SUMMARY
In summary, the construction of a multi-switch musical door bell with indicators was carried out successfully and the circuit components well soldered to their various positions and firmly to the vero board, in order for a melodious output through the buzzer, when operated through the various switches, which are made to be positioned in visible parts of building entrance.
5.2 CONCLUSION
The aim of carrying out a project is to make the students adopt the theories into the practical realization for the benefits of man kind. The construction of a multi switch musical doorbell with indicators consist of
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various components into connected in a systematic manner that the bell brings out a reliable output in the form of sound signal through the buzzer. In conclusion, I wish to state here that, in any construction, it is not an easy assignment among others: time, planning, reading, research, modifications, and challenges to cope with.
5.3 RECOMMENDATIONS
This project work has it’s limitations among which are time factor, technical specification and finance. These areas should be looked into for improvement in subsequent work on the same topic through the following points or areas.
1. Project Writing and Construction should be taught with much emphasis laid on the requirements needed.
2. Government and industries/industrial training fund should contribute fifty percent of the project development. This will make the products to be of quality to compete in the market.
3. The project as a course should be weighted the same as such courses like electronics, telecommunications, electrical power, circuit theory and machines etc, so that the graduates will be more serious on it than now.
REFERENCES
B.L. Thereja Electrical Technology Vol. 1
A.K. Thereja
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Donald E. Scott Introduction to Circuit Analysis & System Approach
Glence Mc Gan-Hill Electronic Principle (Sixth Edition)
Boylestad Nashelsky Electronic device and Circuit Theory
(7th Edition)
Hughes Electrical/Electronics Technology
(8th Edition)

Tuesday, January 19, 2010

CONSTRUCTION OF A DEMONSTRATION VARIABLE REGULATED D.C. POWER SUPPLY UNIT

CONSTRUCTION OF A DEMONSTRATION VARIABLE REGULATED D.C. POWER SUPPLY UNIT


BY

AMADI UCHENNA

CHAPTER ONE
1.0 INTRODUCTION
With the rapid growth of highly developed technology of instant communication, computerization, industrial automation and space exploration, the feats would not have been possible without the advent of electrical / electronics engineering. In electrical and telecommunication engineering field, systems and equipments like amplifiers, satellites, microwave link systems to name but a few depend for their correct operations upon the availability of stable well regulated d.c. power supplies. In experimental laboratories, the use of well regulated d.c. power supplies becomes inevitable because the result of these experiment depends largely on the quality power supply used.

The construction of this piece of electronic equipment will find use both now and in future. The main requirement of a well regulated d.c. power supply unit are: good regulations, low ripple, low output impedance and strict output short-circuit protection.

1.1 BACKGROUND OF THE STUDY:
In recent times variable d.c power supply unit have become very useful and popular and popular to power d.c. equipments. When d.c. supplies of different values are required while accumulation of different values could be used, it is cheaper and more convenient to use a variable d.c. supply hence the important of variable d.c. power supply.

1.2 PURPOSE OF THE PROJECT:
The purpose of this work or project is to construct a demonstration how a variable d.c. power is realize and works.

1.3 SCOPE OF THE PROJECT
The project is limited to the construction and demonstration of a variable d.c. power supply and the voltage range is from 0 to 15 volts.

1.4 DEFINITION OF TERMS:
TRANSFORMER: This is an electrical device used mainly for voltage transformation to the required level.

FUSE:- This is a short piece of wire inside electrical equipment which prevent damage by melting and stopping the electricity when there is too much power.

INTEGRATED CIRCUIT: This is a very small set of electronics connection printed on a single piece of semi conductor material instead of being made from separated parts.

RECTIFICATION: This is a process of converting alternating or changing current to direct unidirectional current.

SEMI-CONDUCTOR: This is a material whose conducting ability lies between that of conducting and insulators.

BRIDGE RECTIFICATION: This is a block or group of four diodes arrange or connected such that two diodes conduct at every half ciycle to give a d.c. output.

CHAPTER TWO

2.0 LITERATURE REVIEW
2.1 TRANSFORMERS: This is an electrical device used mainly for voltage transformation to the required levels. Transformers come in various sizes, some transformers are as large as a room, and others can be as small as a cube of sugar. The basic parts of a transformer are primary winding usually connected to the input signals. The secondary winding is connected to the load. The core of the transformer is another important part of the device. The illustration in figure 2.1 shows a step down transformer. There are voltage and current transformers which could be auto transformers or separately wound transformers and many others.
Core

Primary Winding Secondary Winding

Figure 2.1 Step down transformer showing the main part of the device

2.2 RECTIFIERS: Conversion of alternating current or voltage into direct current is called rectification. A diode whether crystal or electronic is used as a rectifier because it conduct current only in one direction. Half wave rectification uses one diode, full wave rectifiers uses tow diodes whereas a bridge rectifier has four diodes.

2.3 FULL WAVE RECTIFICATION: Here the diodes conduct in both cycles of the input. Full wave rectification uses of a center tap transformers is essential when only two diodes are used. There is the need for centre tapped transformers with bridge rectifier.

2.4 FULL WAVE BRIDGE RECTIFIER: it is the most frequently used circuit for electronic d.c power supplier. It requires four diodes but the transformer used is not centre taped and has a maximum voltage across it secondary winding as show in figure 2.2

Figure 2.2 Full Wave Bridge Rectifier circuit
2.5 FILTER: The rectifier’s circuit described produces the required direct current in the load. The d.c. is however not ready or smooth. In most application it is desirable to keep this latter component small. This can be accomplished by the use of a smoothening or filter circuit. The simplest of which consist of a capacitor in parallel with the load as shown in figure 2.3.

The diodes conduct when the supply voltage V is more positive than the load voltage VR. During this conducting period, if the diode forward resistance is neglected, then the load voltage is equal to the supplied voltage.









Figure 2.3 A capacitor filter

2.6 UNREGULATED D.C. POWER SUPPLY

This consists of the transformer that steps down the a.c. supply to the desired voltage level. The output of the transformer is then rectified to give a fluctuating d.c. signal. The output of the transformer is fed into the rectifier that converts the low or stepped down a.c. into d.c. The smoothening and filter circuit smoothens the fluctuating d.c. signals and filter out the ripples. The unregulated d.c. output is now connected to the lad which could be any equipment or appliance as shown in figure 2.3.



UNREGULATED D.C. POWER SUPPLY

2.7 REGULATED VARIABLE D.C. POWER SUPPLY
This has the same circuitry from the a.c transformation through the rectifier through the smoothening and filter network. Because of the varying load current, the stabilization and regulating network are incorporated at the output of the filter. The output voltage is varied to the desired level by a potentiometer which sets the output voltage to the required level value. The variation is from zero to the maximum output voltage as shown in the figure below.

REGULATED VARIABLE D.C. POWER

2.8 ADJUSTABLE VOLTAGE REGULATOR
The LM 78xx series of three terminal regulators is available with several fixed output voltages making them useful in a wide range of application. The voltage available allows these regulators to be used in logic systems, instrumentation and other solid state electronic equipment. Although designed primarily as fixed voltage regulator. This device can be used with external components to obtain adjustable and currents.


CHAPTER THREE

3.0 CIRCUIT ANALYSIS AND DESCRIPTION

Variable D.C. Power Supply Circuit Diagram
3.1 CIRCUIT PROTECTION
The circuit is protected by a fuse. A fuse is a short piece of wire designed to melt when the current passing through it exceeds the rated value. It is placed on the live line of the circuit. The 1A fuse used in this project work is to protect the circuit from current beyond 1Amp. All domestic electrical equipment are rated specifying the maximum current, voltage or power required for safe operation.

3.2 THE TRANSFORMER UNIT
The transformer in this project steps down or reduces the mains voltage so that it can be used in the range of electronic circuits. There are two types of transformers, the step up and step down. In this project work, a step down 12v transformer takes in 240v a.c. at it’s primary voltage and reduces it to 12v and this 12v is fed to the rectifier unit.

3.3 RECTIFICATION AND SMOOTHENING NETWORK
Rectification is the process of converting a.c. to d.c. It is use in power supply units for producing low power d.c. from the mains 240v supply.

In this project work, the full wave rectification is achieved by the use of a bridge rectifier consisting of four diodes. The IN4001 Silicon diode with a maximum forward current of 1A and peak reverse voltage of 50V. after the rectification, the d.c. voltage in the circuit has ripples and has to be filtered. This smoothening is achieved by the use of an electrolytic capacitor or a resistor capacitor arrangement of 10µf. The amount of smoothening obtained depends on the size of the capacitor and the size of the load resistance. The larger the time constant, the better the smoothening and the shorter the ripple voltage.

3.4 LM 7815 REGULATOR
The LM 7815 used for this project work is available in an aluminum TO-3 package as in figure above which will allow over 1.0A load current. If adequate heat sinking is provided, current limiting is included to limit the peak output current to safe value. Internal power dissipation becomes too high for the heat sink provided the thermal shut-down circuit takes over preventing the IC from over heating. It provides output voltages ranging from 5v to 10v. Bypassing the output is not necessary though it improves transient response. Input bypassing is needed only when the regulator is located far from the filter capacitor of the supply.

TO – 3

3.5 PRINCIPLE OF OPERATION
The variable regulated d.c. power supply utilizes a 240v ac supply which is stepped down by a 12v transformer. The transformer is connected to a fuse of 1A and a switch to turn on and off the circuit. The circuit is incorporated with four diodes which forms the bridge rectifier circuit. The capacitor and resistor network does the smoothening of the voltage which is rectified by the bridge rectifier. After the smoothening, the LM 7815 voltage regulator takes in the input from it first pin while pin 2 is grounded. The regulated voltage output is on pin 3. A voltmeter is connected with a variable switch which is used to control the d.c output and the d.c. voltmeter indicates the amount of voltage at the output of the Lm 7815 voltage regulator.


CHAPTER FOUR

4.0 Constructional Description and Casing:
The variable regulated dc power supply is constructed on a veroboard measuring 7.5cm by 6.5cm. The thickness is about 2cm. The veroboard has 16 conducting strips with 19 holes by 16 holes in which the components are carefully fixed in base as on the layout diagram of figure below and soldered. The components are well laid out traceable from input to output terminals. The transformer ‘T’, neon lamp, switch, variable resistor, voltmeter as well as the fuse are not soldered on the veroboard so as to reduce the weight of parts on the veroboard, the conducting leads connect them to their respective points as per the circuit diagram particularly. The transformer is so connected not to increase the load on the veroboard which might break or crack the conducting strips. The meter is fixed on the front panel for easy and quick taking of reading. In like mannere, the switch, lamp, and variable resistor control are easily accessible for quick and easy control, the fuse on the other hand has been fixed within the casing but not soldered directly on the veroboard.

There are vent holes on the sides of the casing for cross air circulation and to lover the temperature within the enclosure as the diodes and voltage regulator are semiconductors which are temperature sensitive.

4.1 CASING
The metal casing is made with these dimensions 6cm long, 4cm wide and 7cm high to the component designed. The front view has the power supply switch (ON/OFF), lamp indicator and a variable resistor knob. Also, a voltage meter is on the front view as shown in the figure below:



Figure 4.1 Wiring / Layout Diagram

HP 6202B Regulated DC Power Supply ManualFigure 4.2 Pictorial view of a variable regulated dc power supply unit

4.2 TOOLS USED

S/NO TOOLS FUNCTION
1 Soldering iron It is used to solder components to the veroboard
2 Screw Driver It is use to screw or fasten the transformer to the casing
3 Plier It was used to cut surplus terminals of components
4 Voltmeter It measures the amount of voltage in the circuit
5 Iron brush It is use to clean the bits of the soldering iron
6 Hack saw It is use to cut material for the casing


4.3 PARTS LIST
S/N PARTS VALUES
1 D1, D2, D3, D4. Diodes 1N4001 Silicom 1A
2 Transformer 12V
3 Fixed Resistor 10 ohms
4 Integrated Circuit LM 7815
5 Fuse 1A
6 Variable Resistor B100K
7 Zener Diode 1A
8 C1, C2. Capacitor 100µf
9 Vero board 7.5cm by 6.5cm


CHAPTER FIVE

5.0 TESTING, RECOMMENDATION AND CONCLUSION
5.1 TESTING
After the construction, the system was tested and measurement indicated on the meter. The variable resistor was adjusted and meter readings noted. Some components were replaced to improve the system performance. The power supply unit was tested again for over two hours to ascertain it output level or to 10V.

5.2 RECOMMENDATION
This project has its limitations among which are time factor, technical specification and finance. These areas should be looked into for improvement on subsequent work on the same topic through the following:
1) Project construction and writing should be taught for atleast two semesters of National Diploma two (NDII).
2) Government through such corporate bodies should help fund or finance students’ project to improve the quality and possibly standardize the project for the market.
3) The polytechnic can construct more of this project for use in the laboratory / workshop instead of buying from the market thereby depleting the resources of the institution.
4) The project as a course should be weighted the same as such course as electronics, telecommunication, power system etc so that the students will take it more serious than it is obtained currently. There is still more room for improvement on the variable regulated direct current power supply.

5.3 CONCLUSION
The aim of a project is to make the student adopt the theories into the practical realization for the benefits of mankind.

The circuit was constructed and tested, the output voltage was varied from o to 10 volt. It is a huge success.

Monday, January 18, 2010

How to Make Money From Your Blog

It just had to be the first ‘real’ post on the Blogging to the Bank blog so lets cut to the chase and talk about how to make money from your blog. Millions of people across the globe own blogs, some of them know they can make money from their blogs and some of them do not.

The humble blog started out as an online diary, a way that ordinary people could express their thoughts online and establish their web presence. Some blogs have made people famous and some blogs have gotten people arrested. The blog has evolved and developed into so much more in the last couple of years though, and now a blog can be nearly anything you want it to be; an online store, a magazine website, a salespage, a membership site or just a blog! This is largely thanks to the emergence of wordpress and the various plugins and templates that have been developed over the years. All of these improvements and new features make it easier for people like you and me to own our own blogs and profit from them, so lets look at three real down and dirty tactics that will make you money with your blog!

1. Google Adsense

This is the fastest way to generate some income from your site, but let me warn you up front, you’re not going to make a lot of money with this method. Its just a real quick way to get started.
Google adsense is a program ran by Google where you put some code on your site which allows Google to place content relevant ads on your site. Every time a visitor clicks on one of those adverts you get a few cents. There are various rules to this program and requirements that your website has to meet (having a privacy policy, not telling visitors to click adverts, placing the adverts in a certain manner) but this is a program you can sign up to very quickly at google.com. It doesn’t matter how much traffic you do or you don’t have, Google doesn’t care, as long as you have some where to put the ads, you can do Google Adsense. It won’t make you the kind of money you need to quit your job but its a start!

2. Sell Advertising Space

This is one of the simplest and easy ones to do. Now before you can sell advertising space you want your blog to be getting a bit of traffic. You don’t need thousands of visitors a day, but the more visitors you have, the more you can charge for advertising. To start off with, I’d recommend joining a couple of forums like sitepoint.com and digitalpoint.com and looking through the “advertisers” section in the market place. There you can see what kind of prices are being charged on websites with or without traffic. So for example, if a website with 20k visitors a day is selling a “text link ad” for $100 a month and your site only gets a thousand visitors a day, then for a similar ad, you should be charging less than $100 a month.

You get the idea.

Go to these marketplaces and see what advertising space is popular with people looking to advertise. Make sure you do your research and find a good price point. Once you have done that, post an offer to sell advertising space yourself. Remember to post your site’s stats up and be honest about your traffic numbers and where possible provide proof.

Make sure you don’t let advertisers pay for too many months in advance. The more traffic your site gets, the better Pagerank you receive, the more you can charge for advertising. Once you have mastered all this you can join various ad networks that can make the whole process easier, pay you on a performance basis or simply get you in front of a larger marketplace.

Some blogs make thousands of dollars a month with advertising in many different obscure niches. The best bit about this, it takes virtually no work to maintain to keep the money pouring into your Paypal and bank account!

3. Affiliate Marketing

If you’ve got a loyal readership or if your blog is getting a reasonable amount of visitors then you might want to write a few posts recommending certain services and products and then provide a link to that product’s website. Of course the link you will provide will be a cleverly disguised affiliate link which will then allow you to make a commission on any purchases made by the visitors that visited that site through your link. You don’t want to make every post an advert though encouraging people to buy products. Make sure you give honest recommendations so as to maintain your integrity with your readership ad build trust. You might also want to try and build an email list using your blog so as you can email your subscribers from time to time with updates on your blogs and affiliate promotions.

4. Write Review Posts

I personally love this idea. There are hundreds and thousands of companies out there looking for people in the “blosophere” to write about their products and websites. They are so desperate for bloggers to talk about them they have even started paying them to do it! And now there are websites that put companies and bloggers together so that bloggers can get paid for a post they make about a company.

Basically you add your blog profile to one of these sites and companies in your niche or market may contact you and ask you to write a blog post in exchange for a value of money. How much money you get paid depends on your Pagerank and how many visitors you get to your site etc etc. Some people make $40 a post while others make $6000 a post. Its easy money once you get into it. If you’re interested in getting into this then go check out reviewme.com and sign up with your blog.

Alternatively, there is another site (payperpost.com) which allows companies to state what they are looking for and what they will pay, and bloggers can take them up on their offers as long as their blog meets the criteria laid down by the company in the campaign description. In fact, there are a lot of sites around that allow for this kind of work, its just a case of using our god friend Google to find them!

Try and not over do it with review posts etc though, as again you’ll lose the trust and goodwill of your readership.

So there are four of the most popular things you can do to make money with your blog. Some you can do today and see results with today, and some that take a little longer. If you’re a smart cookie, you’ll have noticed a trend in all of the techniques I have mentioned. The more traffic your site has, the more money you can make. That really will be the key to your success. You can still make money with a little traffic, and ten invest that little bit of money into generating more traffic. Once you get that traffic you can start charging more and making more money and then suddenly you are in profit. It doesn’t happen overnight, it might take a month or two of work, but it is doable and people are doing it every day.

It doesn’t matter if your blog isn’t the best, keep it simple and get some dam content up on it! Worry about tweaking it and making it uber cool later! Just build some backlinks and get some traffic to that thing!

So I hope this article has helped you out in figuring out what you want to do to make money from your blog. There are other ways you can profit from your blog, but these are some of the quickest, easiest and most basic ways of making with a blog. I wish you all the best, and as usual, if you’ve got any questions or anything to say about my post today, feel free to reach out, get in touch and leave a comment below.