design of solar power system for home application
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DESIGN OF SOLAR POWER SYSTEM FOR HOME APPLICATION
ABSTRACT:
In this project, a design of solar cell is presented. A solar cell or photovoltaic cell is a
device which generates electricity directly from visible light by means of the photovoltaic
effect. In order to generate useful power, it is necessary to connect a number of cells together
to form a solar panel, also known as a photovoltaic module. The nominal output voltage of a
solar panel is usually 12 Volts, and they may be used singly or wired together into an array. The
number and size required is determined by the available light and the amount of energy
required.
The design of the simple solar power system right is to ensuring both reliability of supply and
minimum cost.The PV panel systems may have only a few 12 Volt, but in bigger systems 230 or
110 Volts will probably be needed. The output from a photovoltaic (PV) cell is insufficient to
operate a large DC load. A Boost converter is used to transform the low voltage DC generated
by the solar panels into high voltage DC. In many small scale industries and residential a DC
motor is the only source to run a machine. According to our proposed system 40% of the power
consumption of the industries may reduce as well as our system increases the efficiency of the
industries or home applications.
Introduction:
In today's climate of growing energy needs and increasing environmental concern, alternatives
to the use of non-renewable and polluting fossil fuels have to be investigated. One such
alternative is solar energy.
Solar energy is quite simply the energy produced directly by the sun and collected elsewhere,
normally the Earth. The sun creates its energy through a thermonuclear process that converts
about 650,000,000 tons of hydrogen to helium every second. The process creates heat and
electromagnetic radiation. The heat remains in the sun and is instrumental in maintaining the
thermonuclear reaction. The electromagnetic radiation (including visible light, infra-red light,
and ultra-violet radiation) streams out into space in all directions.
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Only a very small fraction of the total radiation produced reaches the Earth. The radiation that
does reach the Earth is the indirect source of nearly every type of energy used today. The
exceptions are geothermal energy, and nuclear fission and fusion. Even fossil fuels owe their
origins to the sun; they were once living plants and animals whose life was dependent upon the
sun.
Much of the world's required energy can be supplied directly by solar power. More still can be
provided indirectly. The practicality of doing so will be examined, as well as the benefits and
drawbacks. In addition, the uses solar energy is currently applied to will be noted.
Due to the nature of solar energy, two components are required to have a functional solar
energy generator. These two components are a collector and a storage unit. The collector
simply collects the radiation that falls on it and converts a fraction of it to other forms of energy
(either electricity and heat or heat alone). The storage unit is required because of the non-
constant nature of solar energy; at certain times only a very small amount of radiation will be
received. At night or during heavy cloudcover, for example, the amount of energy produced by
the collector will be quite small. The storage unit can hold the excess energy produced during
the periods of maximum productivity, and release it when the productivity drops. In practice, a
backup power supply is usually added, too, for the situations when the amount of energy
required is greater than both what is being produced and what is stored in the container.
Methods of collecting and storing solar energy vary depending on the uses planned for the solar
generator. In general, there are three types of collectors and many forms of storage units.
The three types of collectors are flat-plate collectors, focusing collectors, and passive collectors.
Flat-plate collectors are the more commonly used type of collector today. They are arrays of
solar panels arranged in a simple plane. They can be of nearly any size, and have an output that
is directly related to a few variables including size, facing, and cleanliness. These variables all
affect the amount of radiation that falls on the collector. Often these collector panels have
automated machinery that keeps them facing the sun. The additional energy they take in due to
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the correction of facing more than compensates for the energy needed to drive the extra
machinery.
Focusing collectors are essentially flat-plane collectors with optical devices arranged to
maximize the radiation falling on the focus of the collector. These are currently used only in a
few scattered areas. Solar furnaces are examples of this type of collector. Although they can
produce far greater amounts of energy at a single point than the flat-plane collectors can, they
lose some of the radiation that the flat-plane panels do not. Radiation reflected off the ground
will be used by flat-plane panels but usually will be ignored by focusing collectors (in snow
covered regions, this reflected radiation can be significant). One other problem with focusing
collectors in general is due to temperature. The fragile silicon components that absorb the
incoming radiation lose efficiency at high temperatures, and if they get too hot they can even
be permanently damaged. The focusing collectors by their very nature can create much higher
temperatures and need more safeguards to protect their silicon components.
Passive collectors are completely different from the other two types of collectors. The passive
collectors absorb radiation and convert it to heat naturally, without being designed and built to
do so. All objects have this property to some extent, but only some objects (like walls) will be
able to produce enough heat to make it worthwhile. Often their natural ability to convert
radiation to heat is enhanced in some way or another (by being painted black, for example) and
a system for transferring the heat to a different location is generally added.
People use energy for many things, but a few general tasks consume most of the energy. These
tasks include transportation, heating, cooling, and the generation of electricity. Solar energy
can be applied to all four of these tasks with different levels of success.
Heating is the business for which solar energy is best suited. Solar heating requires almost no
energy transformation, so it has a very high efficiency. Heat energy can be stored in a liquid,
such as water, or in a packed bed. A packed bed is a container filled with small objects that can
hold heat (such as stones) with air space between them. Heat energy is also often stored in
phase-changer or heat-of-fusion units. These devices will utilize a chemical that changes phase
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from solid to liquid at a temperature that can be produced by the solar collector. The energy of
the collector is used to change the chemical to its liquid phase, and is as a result stored in the
chemical itself. It can be tapped later by allowing the chemical to revert to its solid form. Solar
energy is frequently used in residential homes to heat water. This is an easy application, as the
desired end result (hot water) is the storage facility. A hot water tank is filled with hot water
during the day, and drained as needed. This application is a very simple adjustment from the
normal fossil fuel water heaters.
Swimming pools are often heated by solar power. Sometimes the pool itself functions as the
storage unit, and sometimes a packed bed is added to store the heat. Whether or not a packed
bed is used, some method of keeping the pool's heat for longer than normal periods (like a
cover) is generally employed to help keep the water at a warm temperature when it is not in
use.
Solar energy is often used to directly heat a house or building. Heating a building requires much
more energy than heating a building's water, so much larger panels are necessary. Generally a
building that is heated by solar power will have its water heated by solar power as well. The
type of storage facility most often used for such large solar heaters is the heat-of-fusion storage
unit, but other kinds (such as the packed bed or hot water tank) can be used as well. This
application of solar power is less common than the two mentioned above, because of the cost
of the large panels and storage system required to make it work. Often if an entire building is
heated by solar power, passive collectors are used in addition to one of the other two types.
Passive collectors will generally be an integral part of the building itself, so buildings taking
advantage of passive collectors must be created with solar heating in mind.
These passive collectors can take a few different forms. The most basic type is the incidental
heat trap. The idea behind the heat trap is fairly simple. Allow the maximum amount of light
possible inside through a window (The window should be facing towards the equator for this to
be achieved) and allow it to fall on a floor made of stone or another heat holding material.
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During the day, the area will stay cool as the floor absorbs most of the heat, and at night, the
area will stay warm as the stone re-emits the heat it absorbed during the day.
Another major form of passive collector is thermosyphoning walls and/or roof. With this
passive collector, the heat normally absorbed and wasted in the walls and roof is re-routed into
the area that needs to be heated.
The last major form of passive collector is the solar pond. This is very similar to the solar heated
pool described above, but the emphasis is different. With swimming pools, the desired result is
a warm pool. With the solar pond, the whole purpose of the pond is to serve as an energy
regulator for a building. The pond is placed either adjacent to or on the building, and it will
absorb solar energy and convert it to heat during the day. This heat can be taken into the
building, or if the building has more than enough heat already, heat can be dumped from the
building into the pond.
Solar energy can be used for other things besides heating. It may seem strange, but one of the
most common uses of solar energy today is cooling. Solar cooling is far more expensive than
solar heating, so it is almost never seen in private homes. Solar energy is used to cool things by
phase changing a liquid to gas through heat, and then forcing the gas into a lower pressure
chamber. The temperature of a gas is related to the pressure containing it, and all other things
being held equal, the same gas under a lower pressure will have a lower temperature. This cool
gas will be used to absorb heat from the area of interest and then be forced into a region of
higher pressure where the excess heat will be lost to the outside world. The net effect is that of
a pump moving heat from one area into another, and the first is accordingly cooled.
Besides being used for heating and cooling, solar energy can be directly converted to electricity.
Most of our tools are designed to be driven by electricity, so if you can create electricity
through solar power, you can run almost anything with solar power. The solar collectors that
convert radiation into electricity can be either flat-plane collectors or focusing collectors, and
the silicon components of these collectors are photovoltaic cells.
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Photovoltaic cells, by their very nature, convert radiation to electricity. This phenomenon has
been known for well over half a century, but until recently the amounts of electricity generated
were good for little more than measuring radiation intensity. Most of the photovoltaic cells on
the market today operate at an efficiency of less than 15%; that is, of all the radiation that falls
upon them, less than 15% of it is converted to electricity. The maximum theoretical efficiency
for a photovoltaic cell is only 32.3%, but at this efficiency, solar electricity is very economical.
Most of our other forms of electricity generation are at a lower efficiency than this.
Unfortunately, reality still lags behind theory and a 15% efficiency is not usually considered
economical by most power companies, even if it is fine for toys and pocket calculators. Hope for
bulk solar electricity should not be abandoned, however, for recent scientific advances have
created a solar cell with an efficiency of 28.2%efficiency in the laboratory. This type of cell has
yet to be field tested. If it maintains its efficiency in the uncontrolled environment of the
outside world, and if it does not have a tendency to break down, it will be economical for
power companies to build solar power facilities after all.
Of the main types of energy usage, the least suited to solar power is transportation. While
large, relatively slow vehicles like ships could power themselves with large onboard solar
panels, small constantly turning vehicles like cars could not. The only possible way a car could
be completely solar powered would be through the use of battery that was charged by solar
power at some stationary point and then later loaded into the car. Electric cars that are partially
powered by solar energy are available now, but it is unlikely that solar power will provide the
world's transportation costs in the near future.
Solar power has two big advantages over fossil fuels. The first is in the fact that it is renewable;
it is never going to run out. The second is its effect on the environment.
While the burning of fossil fuels introduces many harmful pollutants into the atmosphere and
contributes to environmental problems like global warming and acid rain, solar energy is
completely non-polluting. While many acres of land must be destroyed to feed a fossil fuel
energy plant its required fuel, the only land that must be destroyed for a solar energy plant is
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the land that it stands on. Indeed, if a solar energy system were incorporated into every
business and dwelling, no land would have to be destroyed in the name of energy. This ability
to decentralize solar energy is something that fossil fuel burning cannot match.
As the primary element of construction of solar panels, silicon, is the second most common
element on the planet, there is very little environmental disturbance caused by the creation of
solar panels. In fact, solar energy only causes environmental disruption if it is centralized and
produced on a gigantic scale. Solar power certainly can be produced on a gigantic scale, too.
Among the renewable resources, only in solar power do we find the potential for an energy
source capable of supplying more energy than is used.
Suppose that of the 4.5x1017
kWh per annum that is used by the earth to evaporate water from
the oceans we were to acquire just 0.1% or 4.5x1014
kWh per annum. Dividing by the hours in
the year gives a continuous yield of 2.90x1010
kW. This would supply 2.4 kW to 12.1 billion
people.
This translates to roughly the amount of energy used today by the average American available
to over twelve billion people. Since this is greater than the estimated carrying capacity of the
Earth, this would be enough energy to supply the entire planet regardless of the population.
Unfortunately, at this scale, the production of solar energy would have some unpredictable
negative environmental effects. If all the solar collectors were placed in one or just a few areas,
they would probably have large effects on the local environment, and possibly have large
effects on the world environment. Everything from changes in local rain conditions to another
Ice Age has been predicted as a result of producing solar energy on this scale. The problem lies
in the change of temperature and humidity near a solar panel; if the energy producing panels
are kept non-centralized, they should not create the same local, mass temperature change that
could have such bad effects on the environment.
Of all the energy sources available, solar has perhaps the most promise. Numerically, it is
capable of producing the raw power required to satisfy the entire planet's energy needs.
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Environmentally, it is one of the least destructive of all the sources of energy. Practically, it can
be adjusted to power nearly everything except transportation with very little adjustment, and
even transportation with some modest modifications to the current general system of travel.
Clearly, solar energy is a resource of the future.
Photovoltaic Cells
Photovoltaic (PV) cells, which convert light directly into electricity, have become commonplace
on devices such as calculators and watches. There are a number of technologies in
development with the aim of making PV more economic for electrical power generation. All use
semiconductor materials like those used in silicon chips.
Photovoltaic (PV) power systems convert sunlight directly into electricity. A residential PVpower system enables a homeowner to generate some or all of their daily electrical energy
demand on their own roof, exchanging daytime excess power for future energy needs (i.e.
nighttime usage). The house remains connected to the electric utility at all times, so any power
needed above what the solar system can produce
is simply drawn from the utility. PV systems can also include battery backup or uninterruptible
power supply (UPS) capability to operate selected circuits in the residence for hours or days
during a utility outage. The purpose of this document is to provide tools and guidelines for the
installer to help ensure that residential photovoltaic power systems are properly specified and
installed, resulting in a system that operates to its design potential. This document sets out key
criteria that describe a quality system, and key design and installation considerations that
should be met to achieve this goal. This document deals with systems located on residences
that are connected to utility power, and does not address the special issues of homes that are
remote from utility power.
In this early stage of marketing solar electric power systems to the residential market, it is
advisable for an installer to work with well established firms that have complete, pre-
engineered packaged solutions that accommodate variations in models, rather than custom
designing custom systems. Once a system designhas been chosen, attention to installation
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detail is critically important. Recent studies have found that 10-20% of new PV installations
have serious installation problems that will result in significantly decreased
performance.
The heart of a PV cell is the interface between two different types of semiconductor. When a
light photon hits a silicon atom in this region, it throws out an electron. The electron can travel
through the n-type semiconductor to metal contacts on the surface. The hole left by the
absence of the electron travels in the opposite direction. Once at the metal contact the
electron flows through an electrical circuit back to meet up with a hole at the other contact.
As it flows through the external circuit, the electron does useful work, like charging a battery, or
operating an electrical appliance. Photovoltaic systems have been reducing in cost, and
increasing in efficiency in recent years. The most efficient commercially available systems can
convert up to 16% of the light energy that strikes them into electrical energy.
Boost converter
A boost converter (step-up converter) is a power converter with an output DC voltage greater
than its input DC voltage. It is a class ofswitching-mode power supply (SMPS) containing at
least two semiconductor switches (a diode and a transistor) and at least one energy storage
element. Filters made ofcapacitors (sometimes in combination with inductors) are normally
added to the output of the converter to reduce output voltage ripple.
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Overview
Power can also come from DC sources such as batteries, solar panels, rectifiers and DC
generators. A process that changes one DC voltage to a different DC voltage is called DC to DC
conversion. A boost converter is a DC to DC converter with an output voltage greater than the
source voltage. A boost converter is sometimes called a step-up converter since it steps up
the source voltage. Since power (P = VI) must be conserved, the output current is lower than
the source current.
A boost converter may also be referred to as a 'Joule thief'. This term is usually used only with
very low power battery applications, and is aimed at the ability of a boost converter to 'steal'
the remaining energy in a battery. This energy would otherwise be wasted since a normal load
wouldn't be able to handle the battery's low voltage.
History
For high efficiency, the SMPS switch must turn on and off quickly and have low losses. The
advent of a commercial semiconductor switch in the 1950s represented a major milestone that
made SMPSs such as the boost converter possible. Semiconductor switches turned on and off
more quickly and lasted longer than other switches such as vacuum tubes and
electromechanical relays. The major DC to DC converters were developed in the early 1960s
when semiconductor switches had become available. The aerospace industrys need for small,
lightweight, and efficient power converters led to the converters rapid development.
Switched systems such as SMPS are a challenge to design since its model depends on whether a
switch is opened or closed. R.D. Middlebrook from Caltech in 1977 published the models for DC
to DC converters used today. Middlebrook averaged the circuit configurations for each switch
state in a technique called state-space averaging. This simplification reduced two systems into
one. The new model led to insightful design equations which helped SMPS growth.
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Applications
Battery powered systems often stack cells in series to achieve higher voltage. However,
sufficient stacking of cells is not possible in many high voltage applications due to lack of space.
Boost converters can increase the voltage and reduce the number of cells. Two battery-
powered applications that use boost converters are hybrid electric vehicles (HEV) and lighting
systems.
The Toyota Prius HEV uses a 500 V motor. Without a boost converter, the Prius would need
nearly 417 cells to power the motor. However, a Prius actually uses only 168 cells and boosts
the battery voltage from 202 V to 500 V. Boost converters also power devices at smaller scale
applications, such as portable lighting systems. A white LED typically requires 3.3 V to emit light,
and a boost converter can step up the voltage from a single 1.5 V alkaline cell to power the
lamp. Boost converters can also produce higher voltages to operate cold cathode fluorescent
tubes (CCFL) in devices such as LCD backlights and some flashlights.
Circuit analysis
Operating principle
The key principle that drives the boost converter is the tendency of an inductor to resist
changes in current. When being charged it acts as a load and absorbs energy (somewhat like a
resistor), when being discharged, it acts as an energy source (somewhat like a battery). The
voltage it produces during the discharge phase is related to the rate of change of current, and not
to the original charging voltage, thus allowing different input and output voltages.
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Fig. 1:Boost converter schematic
Fig. 2: The two configurations of a boost converter, depending on the state of the switch S.
The basic principle of a Boost converter consists of 2 distinct states (see figure 2):
in the On-state, the switch S (see figure 1) is closed, resulting in an increase in the inductor
current;
in the Off-state, the switch is open and the only path offered to inductor current is through the
flyback diode D, the capacitor C and the load R. This results in transferring the energy
accumulated during the On-state into the capacitor.
The input current is the same as the inductor current as can be seen in figure 2. So it is not
discontinuous as in the buck converter and the requirements on the input filter are relaxed
compared to a buck converter.
Continuous mode
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Fig. 3:Waveforms of current and voltage in a boost converter operating in continuous mode.
When a boost converter operates in continuous mode, the current through the inductor (IL) never
falls to zero. Figure 3 shows the typical waveforms of currents and voltages in a converter
operating in this mode. The output voltage can be calculated as follows, in the case of an ideal
converter (i.e. using components with an ideal behaviour) operating in steady conditions:
During the On-state, the switch S is closed, which makes the input voltage (Vi) appear across the
inductor, which causes a change in current (IL) flowing through the inductor during a time period
(t) by the formula:
At the end of the On-state, the increase of IL is therefore:
D is the duty cycle. It represents the fraction of the commutation period T during which the
switch is On. Therefore D ranges between 0 (S is never on) and 1 (S is always on).
During the Off-state, the switch S is open, so the inductor current flows through the load. If we
consider zero voltage drop in the diode, and a capacitor large enough for its voltage to remain
constant, the evolution of IL is:
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Therefore, the variation of IL during the Off-period is:
As we consider that the converter operates in steady-state conditions, the amount of energystored in each of its components has to be the same at the beginning and at the end of a
commutation cycle. In particular, the energy stored in the inductor is given by:
So, the inductor current has to be the same at the start and end of the commutation cycle. This
means the overall change in the current (the sum of the changes) is zero:
This can be written as:
Which in turns reveals the duty cycle to be:
From the above expression it can be seen that the output voltage is always higher than the input
voltage (as the duty cycle goes from 0 to 1), and that it increases with D, theoretically to infinity
as D approaches 1. This is why this converter is sometimes referred to as a step-up converter.
Discontinuous mode
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Fig. 4:Waveforms of current and voltage in a boost converter operating in discontinuous mode.
In some cases, the amount of energy required by the load is small enough to be transferred in a
time smaller than the whole commutation period. In this case, the current through the inductor
falls to zero during part of the period. The only difference in the principle described above is
that the inductor is completely discharged at the end of the commutation cycle (see waveforms
in figure 4). Although slight, the difference has a strong effect on the output voltage equation. It
can be calculated as follows:
As the inductor current at the beginning of the cycle is zero, its maximum value (at t = DT) is
During the off-period, IL falls to zero after T:
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Using the two previous equations, is:
The load current Io is equal to the average diode current (ID). As can be seen on figure 4, the
diode current is equal to the inductor current during the off-state. Therefore the output current
can be written as:
Replacing ILmaxand by their respective expressions yields:
Therefore, the output voltage gain can be written as flow:
Compared to the expression of the output voltage for the continuous mode, this expression is
much more complicated. Furthermore, in discontinuous operation, the output voltage gain not
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only depends on the duty cycle, but also on the inductor value, the input voltage, the switching
frequency, and the output current.
BLOCK DIAGRAM:
HARDWARE DETAILDRIVER CIRCUIT
The driver circuit is supplied using a step down transformer 230V/12V AC .In this project the
driver circuit is mainly used to amplify the pulse output coming from the microcontroller
circuit.The output from pin 1 and 2 of PIC16F877A is passed to the buffer IC CD4050 .The buffer
IC acts as a NOT gate .the output from the buffer IC is passed to the two optocoupler
R1
1k
R2
R3R4
R5
R6
1k
R8
1k
U1
OP-07C/301/TIQ1
BDX37
Q2
Q3
D1
D1N1190
C1
1n
0
FROM MICRO CONTROLLER
1K
100100
100
S
G500mA
230/12VMCT2E
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respectively. The optocoupler is used to isolate the voltages between the main circuit and
microcontroller circuit. This signal is passed to the transistors CK100 and 2N2222 which is
connected in a Darlington pair model. The driver circuit has two legs. First leg is connected to
switch-1 Sm and the second leg is connected to switch-2 Sa. Thus the 5V pulse from the
microcontroller circuit is amplified to 12V and sent to MOSFET switch.
POWER SUPPLY
POWER SUPPLY UNIT
Fig 1: Block diagram of power supply unit
As we all know any invention of latest technology cannot be activated without the source of
power. So it this fast moving world we deliberately need a proper power source which will be
apt for a particular requirement. All the electronic components starting from diode to Intel ICs
only work with a DC supply ranging from -+5v to 0-+12v. We are utilizing for the same, the
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cheapest and commonly available energy source of 230v-50Hz and stepping down, rectifying,
filtering and regulating the voltage. This will be dealt briefly in the forth-coming sections.
STEP DOWN TRANSFORMER
When AC is applied to the primary winding of the power transformer it can either be stepped
down or up depending on the value of DC needed. In our circuit the transformer of 230v/0-12v
is used to perform the step down operation where a 230V AC appears as 12V AC across the
secondary winding. One alteration of input causes the top of the transformer to be positive and
the bottom negative. The next alteration will temporarily cause the reverse. The current rating
of the transformer used in our project is 1A. Apart from stepping down AC voltages, it gives
isolation between the power source and power supply circuitries.
DIODE BRIDGE RECTIFIERS
The ac input from the main supply is stepped down using a 230 /30V step down transformer.
The stepped down AC voltage is converted into dc voltage using a diode bridge rectifier. The
diode bridge rectifier consists of four diodes arranged in two legs. The diodes are connected to
the stepped down AC voltage. For positive half cycle of the ac voltage, the diodes D1 and D4 are
forward biased (ref fig). For negative half cycles diodes D2 and D3 are forward biased. Thus dc
voltage is produced to provide input supply to the DC-DC Converter.
FIG 2.DIODE BRIDGE RECTIFIER
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When the positive half cycle is applied to the diode bridge rectifier, the diodes D1 and D4 are
forward biased. The diodes start conducting and the load current flows through the positive of
the supply, diodeD1, the load, the diode D4 and the negative of the supply. The diode D2 and
D3 are reverse biased and do not conduct. During the negative half cycle, the diodes D1 and D4
areb reverse biased and they stop conducting. The diodes D2 & D3 are forward biased and they
start conducting. The load current flows in the same direction for both the half cycles. Thus the
ac supply given to diode bridge rectifier is converted into pulsating dc.
FILTERING UNIT
Filter circuits which are usually capacitors acting as a surge arrester always follow the rectifier
unit. This capacitor is also called as a decoupling capacitor or a bypassing capacitor, is used not
only to short the ripple with frequency of 120Hz to ground but also to leave the frequency of
the DC to appear at the output. A load resistor R1 is connected so that a reference to the
ground is maintained. C1R1 is for bypassing ripples. C2R2 is used as a low pass filter, i.e. it
passes only low frequency signals and bypasses high frequency signals. The load resistor should
be 1% to 2.5% of the load.
1000f/25v : for the reduction of ripples from the pulsating.
10f/25v : for maintaining the stability of the voltage at the load side.
O, 1f : for bypassing the high frequency disturbances.
VOLTAGE REGULATORS:
The voltage regulators play an important role in any power supply unit. The primary purpose of
a regulator is to aid the rectifier and filter circuit in providing a constant DC voltage to the
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device. Power supplies without regulators have an inherent problem of changing DC voltage
values due to variations in the load or due to fluctuations in the AC liner voltage. With a
regulator connected to the DC output, the voltage can be maintained within a close tolerant
region of the desired output IC7805 is used in this project for providing +12v and 12v DC
supply.
DRIVER CIRCUIT COMPONENTS
The driver circuit is used to amplify the pulses. It consists of three main components they are:
o OPTOCOUPLER
o BUFFER IC
o TRANSISTOR
OPTOCOUPLER
Introduction
There are many situations where signals and data need to be transferred from
one subsystem to another within a piece of electronics equipment, or from one piece of
equipment to another, without making a direct ohmic electrical connection. Often this is
because the source and destination are (or may be at times) at very different voltage levels, like
a microprocessor, which is operating from 5V DC but being used to control a MOSFET that is
switching at a higher voltage. In such situations the link between the two must be an isolated
one, to protect the microprocessor from over voltage damage.Relays can of course provide this
kind of isolation, but even small relays tend to be fairly bulky compared with ICs and many of
todays other miniature circuit components. Because theyre electro-mechanical, relays are also
not as reliable and only capable of relatively low speed operation. Where small size, higher
speed and greater reliability are important, a much better alternative is to use an optocoupler.
These use a beam of light to transmit the signals or data across an electrical barrier, and
achieve excellent isolation. Optocouplers typically come in a small 6-pin or 8-pin IC package, but
are essentially a combination of two distinct devices: an optical transmitter, typically a gallium
arsenide LED (light-emitting diode) and an optical receiver such as a phototransistor or light-
triggered diac. The two are separated by a transparent barrier which blocks any electrical
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current flow between the two, but does allow the passage of light. The basic idea is shown in
Fig.1, along with the usual circuit symbol for an optocoupler. Usually the electrical connections
to the LED section are brought out to the pins on one side of the package and those for the
phototransistor or diac to the other side, to physically separate them as much as possible. This
usually allows optocouplers to withstand voltages of anywhere between 500V and 7500V
between input and output. Optocouplers are essentially, digital or switching devices, so they re
best for transferring either on-off control signals or digital data. Analog signals can be
transferred by means of frequency or pulse-width modulation.
Key Parameters
The most important parameter for most optocouplers is their transfer efficiency, usually
measured in terms of their current transfer ratio or CTR. This is simply the ratio between a
current change in the output transistor and the current change in the input LED that produced
it. Typical values for CTR range from 10% to 50% for devices with an output phototransistor and
up to 2000% or so for those with a Darlington transistor pair in the output. Note, however that
in most devices CTR tends to vary with absolute current level. Typically it peaks at a LED current
level of about 10mA, and falls away at both higher and lower current levels Other optocoupler
parameters include the output transistors maximum collector-emitter voltage rating VCE(max),
which limits the supply voltage in the output circuit; the input LEDs maximum current rating
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IF(max), which is used to calculate the minimum value for its series resistor; and the
optocouplers bandwidth, which determines the highest signal frequency that can be
transferred through it ,determined mainly by internal device construction and the performance
of the output phototransistor. Typical opto-couplers with a single output phototransistor may
have a bandwidth of 200 - 300kHz, while those with a Darlington pair are usually about 10
times lower, at around 20 - 30kHz.
GENERAL DESCRIPTION
In our project the optocoupler is used in the driver circuit. They are used to isolate the voltage
between the main circuit and microcontroller circuit. The pulse is provided to the MOSFET
switch using a microcontroller circuit; this circuit produces a waveform of 5V DC. This pulse is
supplied to MOSFET switch which is supplied by 12V AC as the source and destination voltage is
different they have to be isolated, which is done using optocoupler.
MCT2 OR MCT2E OPTOCOUPLER
Specifications
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Gallium Arsenide Diode Infrared Source Optically Coupled to a Silicon npn Phototransistor
High Direct-Current Transfer Ratio
Base Lead Provided for Conventional Transistor Biasing
High-Voltage Electrical Isolation . . .
1.5-kV or 3.55-kV Rating
Plastic Dual-In-Line Package
High-Speed Switching:
tr = 5 s, tf= 5 s Typical
Designed to be Interchangeable with General Instruments MCT2 and MCT2E
BUFFER ICCD4050
The CD4050BC hex buffers are monolithic complementary MOS (CMOS) integratedcircuits constructed with N- and P-channel enhancement mode transistors. These devices
feature logic level conversion using only one supply voltage (VDD). The input signal high level
(VIH) can exceed the VDD supply voltage when these devices are used for logic level
conversions. These devices are intended for use as hex buffers, CMOS to DTL/ TTL converters,
or as CMOS current drivers, and at VDD = 5.0V, they can drive directly two DTL/TTL loads over
the full operating temperature range.
Connection Diagrams
Pin Assignments for DIP
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Schematic Diagrams
CD4050BC1 of 6 Identical Units
Features
Wide supply voltage range: 3.0V to 15V
Direct drive to 2 TTL loads at 5.0V over full temperature range
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High source and sink current capability
Special input protection permits input voltages greater than VDD
Absolute Maximum Ratings
Supply Voltage (VDD) -0.5V to +18V
Input Voltage (VIN) -0.5V to +18V
Voltage at Any Output Pin (VOUT) -0.5V to VDD + 0.5V
Storage Temperature Range (TS) -65C to +150C
Power Dissipation (PD)
Dual-In-Line 700 mWSmall Outline 500 mW
Lead Temperature (TL)
(Soldering, 10 seconds) 260C
Recommended Operating Conditions
Supply Voltage (VDD) 3V to 15VInput Voltage (VIN) 0V to 15V
Voltage at Any Output Pin (VOUT) 0 to VDD
Operating Temperature Range (TA)
CD4049UBC, CD4050BC -40C to +85C
Note 1: Absolute Maximum Ratings are those values beyond which the safety of the device
cannot be guaranteed; they are not meant to imply that the devices should be operated at
these limits. The table of Recommended Operating Conditions and Electrical Characteristicsprovides conditions for actual device operation.
Note 2: VSS = 0V unless otherwise specified
Typical Applications
CMOS to TLL or CMOS at a Lower VDD
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Applications
CMOS hex inverter/buffer
CMOS to DTL/TTL hex converter
CMOS current sink or source driver
CMOS HIGH-to-LOW logic level converter.
TRANSISTOR
In electronics, a transistor is a semiconductor device commonly used to amplify or switch
electronic signals. A transistor is made of a solid piece of a semiconductor material, with at
least three terminals for connection to an external circuit. A voltage or current applied to one
pair of the transistor's terminals changes the current flowing through another pair of terminals.
Because the controlled (output) power can be much larger than the controlling (input) power,
the transistor provides amplification of a signal. The transistor is the fundamental building block
of modern electronic devices, and is used in radio, telephone, computer and other electronic
systems. Some transistors are packaged individually but most are found in integrated circuits.
TRANSISTOR AS AN AMPLIFIER
The above common emitter amplifier is designed so that a small change in voltage in (Vin)
changes the small current through the base of the transistor and the transistor's current
http://en.wikipedia.org/wiki/Electronicshttp://en.wikipedia.org/wiki/Semiconductor_devicehttp://en.wikipedia.org/wiki/Electronic_amplifierhttp://en.wikipedia.org/wiki/Electronicshttp://en.wikipedia.org/wiki/Semiconductorhttp://en.wikipedia.org/wiki/Terminalshttp://en.wikipedia.org/wiki/Electric_powerhttp://en.wikipedia.org/wiki/Gainhttp://en.wikipedia.org/wiki/Electronic_devicehttp://en.wikipedia.org/wiki/Radiohttp://en.wikipedia.org/wiki/Telephonehttp://en.wikipedia.org/wiki/Computerhttp://en.wikipedia.org/wiki/Integrated_circuithttp://en.wikipedia.org/wiki/Integrated_circuithttp://en.wikipedia.org/wiki/Computerhttp://en.wikipedia.org/wiki/Telephonehttp://en.wikipedia.org/wiki/Radiohttp://en.wikipedia.org/wiki/Electronic_devicehttp://en.wikipedia.org/wiki/Gainhttp://en.wikipedia.org/wiki/Electric_powerhttp://en.wikipedia.org/wiki/Terminalshttp://en.wikipedia.org/wiki/Semiconductorhttp://en.wikipedia.org/wiki/Electronicshttp://en.wikipedia.org/wiki/Electronic_amplifierhttp://en.wikipedia.org/wiki/Semiconductor_devicehttp://en.wikipedia.org/wiki/Electronics -
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amplification combined with the properties of the circuit mean that small swings in Vin produce
large changes in Vout..It is important that the operating parameters of the transistor are chosen
and the circuit designed such that as far as possible the transistor operates within a linear
portion of the graph, such as that shown between A and B, otherwise the output signal will
suffer distortion. Various configurations of single transistor amplifier are possible, with some
providing current gain, some voltage gain, and some both. From mobile phones to televisions,
vast numbers of products include amplifiers for sound reproduction, radio transmission, and
signal processing. The first discrete transistor audio amplifiers barely supplied a few hundred
milliwatts, but power and audio fidelity gradually increased as better transistors became
available and amplifier architecture evolved. Modern transistor audio amplifiers of up to a few
hundred watts are common and relatively in expensive. Some musical instrument amplifier
manufacturers mix transistors and vacuum tubes in the same circuit, as some believe tubes
have a distinctive sound.
GENERAL DESCRIPTION
In our project we use transistor in driver circuit. the transistor is used to amplify the signal pulse
coming from the microcontroller circuit .Here we use two main types of transistor namely
CK100
2N2222
These two transistors are present in the driver circuit which is connected in a darlington pair
circuit.
DARLINGTON PAIR CIRCUIT
http://en.wikipedia.org/wiki/Linearhttp://en.wikipedia.org/wiki/Distortionhttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Televisionhttp://en.wikipedia.org/wiki/Amplifierhttp://en.wikipedia.org/wiki/Sound_reproductionhttp://en.wikipedia.org/wiki/Transmitterhttp://en.wikipedia.org/wiki/Signal_processinghttp://en.wikipedia.org/wiki/Watthttp://en.wikipedia.org/wiki/Watthttp://en.wikipedia.org/wiki/Signal_processinghttp://en.wikipedia.org/wiki/Transmitterhttp://en.wikipedia.org/wiki/Sound_reproductionhttp://en.wikipedia.org/wiki/Amplifierhttp://en.wikipedia.org/wiki/Televisionhttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/Distortionhttp://en.wikipedia.org/wiki/Linear -
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In electronics, the Darlington transistor (often called a Darlington pair) is a compound structure
consisting of two bipolar transistors (either integrated or separated devices) connected in such
a way that the current amplified by the first transistor is amplified further by the second one[1]
.
This configuration gives a much higher current gain (written , hfe, or hFE) than each transistor
taken separately and, in the case of integrated devices, can take less space than two individual
transistors because they can use a shared collector. Integrated Darlington pairs come packaged
in transistor-like integrated circuit packages.The Darlington configuration was invented by Bell
Laboratories engineer Sidney Darlington in 1953. He patented the idea of having two or three
transistors on a single chip (and sharing a single collector), but not that of an arbitrary number.
A similar configuration but with transistors of opposite type (NPN and PNP) is the Sziklai pair,
sometimes called the "complementary Darlington
TRANSISTOR-2N2222
http://en.wikipedia.org/wiki/Electronicshttp://en.wikipedia.org/wiki/Bipolar_transistorhttp://en.wikipedia.org/wiki/Darlington_transistor#cite_note-TAoE-0http://en.wikipedia.org/wiki/Darlington_transistor#cite_note-TAoE-0http://en.wikipedia.org/wiki/Electric_currenthttp://en.wikipedia.org/wiki/Gainhttp://en.wikipedia.org/wiki/Integrated_circuithttp://en.wikipedia.org/wiki/Bell_Laboratorieshttp://en.wikipedia.org/wiki/Bell_Laboratorieshttp://en.wikipedia.org/wiki/Sidney_Darlingtonhttp://en.wikipedia.org/wiki/Patenthttp://en.wikipedia.org/wiki/Sziklai_pairhttp://upload.wikimedia.org/wikipedia/commons/4/40/Darlington_configuration.svghttp://upload.wikimedia.org/wikipedia/commons/4/40/Darlington_configuration.svghttp://en.wikipedia.org/wiki/Sziklai_pairhttp://en.wikipedia.org/wiki/Patenthttp://en.wikipedia.org/wiki/Sidney_Darlingtonhttp://en.wikipedia.org/wiki/Bell_Laboratorieshttp://en.wikipedia.org/wiki/Bell_Laboratorieshttp://en.wikipedia.org/wiki/Integrated_circuithttp://en.wikipedia.org/wiki/Gainhttp://en.wikipedia.org/wiki/Electric_currenthttp://en.wikipedia.org/wiki/Darlington_transistor#cite_note-TAoE-0http://en.wikipedia.org/wiki/Bipolar_transistorhttp://en.wikipedia.org/wiki/Electronics -
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The 2N2222, often referred to as the 'quad two' transistor, is a small, common NPN BJT
transistor used for general purpose low-power amplifying or switching applications. It is
designed for low to medium current, low power, medium voltage, and can operate at
moderately high speeds. It was originally made in the TO-18 metal can as shown in the picture,
but is more commonly available now in the cheaper TO-92 packaging, where it is known as the
PN2222 or P2N2222.
FEATURES
High current (max. 800 mA).
Low voltage (max. 40 V).
PINNING
APPLICATIONS
Linear amplification and switching.
http://en.wikipedia.org/wiki/NPN_transistorhttp://en.wikipedia.org/wiki/Bipolar_Junction_Transistorhttp://en.wikipedia.org/wiki/Transistorhttp://en.wikipedia.org/wiki/Amplifierhttp://en.wikipedia.org/wiki/Electric_currenthttp://en.wikipedia.org/wiki/Electric_powerhttp://en.wikipedia.org/wiki/Voltagehttp://en.wikipedia.org/wiki/TO-92http://en.wikipedia.org/wiki/TO-92http://en.wikipedia.org/wiki/Voltagehttp://en.wikipedia.org/wiki/Electric_powerhttp://en.wikipedia.org/wiki/Electric_currenthttp://en.wikipedia.org/wiki/Amplifierhttp://en.wikipedia.org/wiki/Transistorhttp://en.wikipedia.org/wiki/Bipolar_Junction_Transistorhttp://en.wikipedia.org/wiki/NPN_transistor -
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MICROCONTROLLER
Introduction
FIG 1.PIC16F877 A PINOUT
To perform the various operations and conversions required to switch, control and monitor the
devices a processor is needed. The processor may be a microprocessor, micro controller or
embedded controller. In this project an micro controller has been preferred because we require
to generate clock pulse. We have chose PIC16F877A in this project mainly for the following
features.
High-Performance, Enhanced PIC Flash Microcontroller in 40-pin
The PIC16F877A CMOS FLASH-based 8-bit microcontroller is upward compatible with the
PIC16C5x, PIC12Cxxx and PIC16C7x devices. It features 200 ns instruction execution, 256 bytes
of EEPROM data memory, self programming, an ICD, 2 Comparators, 8 channels of 10-bit
Analog-to-Digital (A/D) converter, 2 capture/compare/PWM functions, a synchronous serial
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port that can be configured as either 3-wire SPI or 2-wire I2C bus, a USART, and a Parallel Slave
Port.
MEMORY ORGANIZATION
There are three memory blocks in each of the PIC16F877A devices. The program memory and
data memory have separate buses so that concurrent access can occur and is detailed in this
section.
Program Memory Organization
The PIC16F877A devices have a 13-bit program counter capable of addressing an 8K word x 14
bit program memory space. The PIC16F877A devices have 8K words x 14 bits of Flash program
memory. Accessing a location above the physically implemented address will cause a
wraparound. The Reset vector is at 0000h and the interrupt vector is at 0004h.
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DATA EEPROM AND FLASH PROGRAM MEMORY
The data EEPROM and Flash program memory is readable and writable during normal operation
(over the full VDD range). This memory is not directly mapped in the register file space. Instead,
it is indirectly addressed through the Special Function Registers. There are six SFRs used to read
and write this memory:
EECON1
EECON2
EEDATA
EEDATH
EEADR
EEADRH
When interfacing to the data memory block, EEDATA holds the 8-bit data for read/write and
EEADR holds the address of the EEPROM location being accessed. devices have 128 or 256
bytes of data EEPROM (depending on the device), with an address range from 00h to FFh. On
devices with 128 bytes, addresses from80h to FFh are unimplemented and will wraparound to
the beginning of data EEPROM memory. When writing to unimplemented locations, the on-chip
charge pump will be turned off. When interfacing the program memory block, the EEDATA and
EEDATH registers form a two-byte word that holds the 14-bit data for read/write and the
EEADR and EEADRH registers form a two-byte word that holds the 13-bit address of the
program memory location being accessed. These devices have 4 or 8K words of program Flash,
with an address range from 0000h to 0FFFh for the PIC16F874A and 0000h to 1FFFh for the
PIC16F877A. Addresses above the range of the respective device will wraparound to the
nbeginning of program memory. The EEPROM data memory allows single-byte read and write.
T0 the Flash program memory allows single-word reads and four-word block writes. Program
memory write operations automatically perform an erase-before write on blocks of four words.
A byte write in data EEPROM memory automatically erases the location and writes the new
data (erase-before-write). The write time is controlled by an on-chip timer. The write/erase
voltages are generated by an on-chip charge pump, rated to operate over the voltage range of
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the device for byte or word operations. When the device is code-protected, the CPU may
continue to read and write the data EEPROM memory. Depending on the settings of the write-
protect bits, the device may or may not be able to write certain blocks of the program memory;
however, reads of the program memory are allowed. When code-protected, the device
programmer can no longer access data or program memory; this does NOT inhibit internal
reads or writes.
Architecture:
Two types of Architecture are followed.
I). Van-Neumann Architecture:
The width of addr
ess and data bus is same.
II). Haward Architecture:
The bus width of address and data may not be same. Pipelining is possible
here.
Micro controllers have built-in peripherals, they are:
1. Memory
a. Program Memory (E.g. PROM, Flash memory)
b. Data Memory (E.g. RAM, EEROM)
2. I/O Ports
3. ADC
4. Timers
5. USART
6. Interrupt Controllers
7. PWM / Capture
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PERIPHERALS OF PIC16F877A
As the PIC16F877A is rich in peripherals so you can use it for many different projects
PM DM
I / O
CPU Ports
Timer /
Counter PWM/
Port A
Port B
Port C
Port D
Port E
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PERIPHERALS OF PIC16F877A
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FEATURES OF PIC16F877A
High-Performance RISC CPU
Lead-free; RoHS-compliant
Operating speed: 20 MHz, 200 ns instruction cycle
Operating voltage: 4.0-5.5V
Industrial temperature range (-40 to +85C)
15 Interrupt Sources
35 single-word instructions
All single-cycle instructions except for program branches (two-cycle)
Special Microcontroller Features
Flash Memory: 14.3 Kbytes (8192 words)
Data SRAM: 368 bytes
Data EEPROM: 256 bytes
Self-reprogrammable under software control
In-Circuit Serial Programming via two pins (5V)
Watchdog Timer with on-chip RC oscillator
Programmable code protection
Power-saving Sleep mode
Selectable oscillator options
In-Circuit Debug via two pins
Peripheral Features
33 I/O pins; 5 I/O ports
Timer0: 8-bit timer/counter with 8-bit prescaler
Timer1: 16-bit timer/counter with prescaler
o Can be incremented during Sleep via external crystal/clock
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Timer2: 8-bit timer/counter with 8-bit period register, prescaler and postscaler
Two Capture, Compare, PWM modules
o 16-bit Capture input; max resolution 12.5 ns
o 16-bit Compare; max resolution 200 ns
o 10-bit PWM
Synchronous Serial Port with two modes:
o SPI Master
o I2C Master and Slave
USART/SCI with 9-bit address detection
Parallel Slave Port (PSP)
o 8 bits wide with external RD, WR and CS controls
Brown-out detection circuitry for Brown-Out Reset
Analog Features
10-bit, 8-channel A/D Converter
Brown-Out Reset
Analog Comparator module
o
analog comparators
o Programmable on-chip voltage reference module
o Programmable input multiplexing from device inputs and internal VREF
o Comparator outputs are externally accessible
ADVANTAGES
The 16F877A is one of the most popular PIC microcontrollers and it's easy to see why - it comes
in a 40 pin DIP pinout and it has many internal peripherals. The 40 pins make it easier to use
the peripherals as the functions are spread out over the pins. This makes it easier to decide
what external devices to attach without worrying too much if there enough pins to do the job.
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One of the main advantages is that each pin is only shared between two or three functions so
its easier to decide what the pin function (other devices have up to 5 functions for a pin).
DISADVANTAGE
A disadvantage of the device is that it has no internal oscillator so you will need an externalcrystal of other clock source.
DIODE RECTIFIER-IN4007
The diodes are used to convert AC into DC these are used as half wave rectifier or full wave
rectifier. Three points must he kept in mind while using any type of diode.
Maximum forward current capacity
Maximum reverse voltage capacity
Maximum forward voltage capacity
GENERAL DESCRIPTION
In this project the diode rectifier is used in the main circuit. Usually all the power electronics
circuits are provided with a diode rectifier. This helps to convert the 12V AC voltage to DC
voltage. They are connected at the output of input filters.
FEATURES
Diffused Junction
High Current Capability
Low Forward Voltage Drop
Surge Overload Rating to 30A Peak
Low Reverse Leakage Current
Plastic Material: UL Flammability
Classification Rating 94V-0
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MECHANICAL DATA
Case: Molded Plastic
Terminals: Plated Leads Solderable per
MIL-STD-202, Method 208
Polarity: Cathode Band
Weight: DO-41 0.30 grams (approx) A-405 0.20 grams (approx)
Mounting Position: Any
Marking: Type Number
MOSFET SWITCH-IRFP250N
Definition of MOSFET
(Metal Oxide Semiconductor Field Effect Transistor). The most popular and widely used type of
field effect transistor (see FET). MOSFETs are either NMOS (n-channel) or PMOS (p-channel)
transistors, which are fabricated as individually packaged discrete components for high power
applications as well as by the hundreds of millions inside a single chip (IC).
http://www.pcmag.com/encyclopedia_term/0,2542,t=FET&i=43105,00.asphttp://www.pcmag.com/encyclopedia_term/0,2542,t=FET&i=43105,00.asp -
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GENERAL DESCRIPTION
In our project the MOSFET switch is connected to the main circuit.Here we have two switches
namely
Main switch Sm
Auxiliary switch Sa
The pulse to these switches is given using micro controller PIC16F877A through a driver
circuit. In PIC16F877A the pulse of 5V is generated which is sent to driver circuit, these
signal is amplified to about 12V DC, that is sent to the MOSFET switch Sm and Sarespectively.
USING MOSFET AS A SWITCH
A field effect transistor operates in a very similar way to the transistor that we have just
experimented with except that the main current flow is controlled by an electrostatic field. An
FET has the great advantage that no current flows into the control input (called the gate), the
main current is turned on and off by the level of voltage on the gate.
FETs are available in many different types and with various drive level requirements. We are
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going to keep it simple and not get into these complications. The MOSFET that we will be using
is a logic level MOSFET - they are designed to be driven directly from the output lines of
microcontrollers that is all we need to know!For these experiments we will be using the BS270
N channel MOSFET. As it is designed for logic level inputs we know that when the gate is
connected to ground it is turned off and when the gate is connected to 5 volts it is turned on.
We do not need to use a resistor between the push button switch and the gate because the
current is very very low whatever the input voltage (if kept within 0 to 5 volts).
The MO and the FE
The "metal oxide" in MOS comes from the first devices that used a metal gate over oxide
(silicon dioxide). Subsequently, poly-crystalline silicon was used for the gate, but MOS was
never renamed. The "field-effect" in FET is the electromagnetic field that is generated when the
gate electrode is energized, causing the transistor to turn on or off.
NMOS and PMOS
In NMOS transistors, the silicon channel between the source and drain is of p-type silicon.
When a positive voltage is placed on the gate electrode, it repulses the holes in the p-type
material forming a conducting (pseudo n-type) channel and turning the transistor on. Anegative voltage turns the transistor off. With a PMOS transistor, the opposite occurs. A
positive voltage on the gate turns the transistor off, and a negative voltage turns it on. NMOS
transistors switch faster than PMOS.
CMOS
When an NMOS and PMOS transistor are wired together in a complementary fashion, they
become a CMOS (complementary MOS) gate, which causes no power to be used until thetransistors switch. CMOS is the most widely used microelectronic design process and is found in
almost every electronic product. See n-type silicon, bipolar transistor, chip and FET.
http://www.pcmag.com/encyclopedia_term/0,2542,t=n-type+silicon&i=47578,00.asphttp://www.pcmag.com/encyclopedia_term/0,2542,t=bipolar+transistor&i=59377,00.asphttp://www.pcmag.com/encyclopedia_term/0,2542,t=chip&i=39636,00.asphttp://www.pcmag.com/encyclopedia_term/0,2542,t=FET&i=43105,00.asphttp://www.pcmag.com/encyclopedia_term/0,2542,t=FET&i=43105,00.asphttp://www.pcmag.com/encyclopedia_term/0,2542,t=chip&i=39636,00.asphttp://www.pcmag.com/encyclopedia_term/0,2542,t=bipolar+transistor&i=59377,00.asphttp://www.pcmag.com/encyclopedia_term/0,2542,t=n-type+silicon&i=47578,00.asp -
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INDUCTORS:
An inductor or reactor is a passive electrical component that can store energy in a magnetic
field created by the electric current passing through it. An inductor's ability to store magnetic
energy is measured by its inductance, in units ofhenries. Typically an inductor is a conducting
wire shaped as a coil, the loops help create a strong magnetic field inside the coil due to
Faraday's law of induction. Inductors are one of the basic electronic components used in
electronics where current and voltage change with time, due to the ability of inductors to delay
and reshape alternating currents.An "ideal inductor" has inductance, but no resistance or
capacitance, and does not dissipate energy. A real inductor is equivalent to a combination of
inductance, some resistance due to the resistivity of the wire, and some capacitance. At some
frequency, usually much higher than the working frequency, a real inductor behaves as a
resonant circuit (due to its self capacitance). In addition to dissipating energy in the resistance
of the wire, magnetic core inductors may dissipate energy in the core due to hysteresis, and at
high currents may show other departures from ideal behavior due to nonlinearity.
CONCLUSIONS:
Solar (PV) power system has a great potential in future as one of renewable energy
technologies for off-grid power generation. The hybrid technology, integrating PV with DG,
offers solution to off-grid power generation. The easy installation and maintenance free
operational feature of the hybrid system created more popularity among the rural masses.
http://en.wikipedia.org/wiki/Passive_componenthttp://en.wikipedia.org/wiki/Electronic_componenthttp://en.wikipedia.org/wiki/Energyhttp://en.wikipedia.org/wiki/Magnetic_fieldhttp://en.wikipedia.org/wiki/Magnetic_fieldhttp://en.wikipedia.org/wiki/Electric_currenthttp://en.wikipedia.org/wiki/Inductancehttp://en.wikipedia.org/wiki/Henry_(unit)http://en.wikipedia.org/wiki/Faraday%27s_law_of_inductionhttp://en.wikipedia.org/wiki/Electrical_resistancehttp://en.wikipedia.org/wiki/Capacitancehttp://en.wikipedia.org/wiki/Resonant_circuithttp://en.wikipedia.org/wiki/Parasitic_capacitancehttp://en.wikipedia.org/wiki/Hysteresishttp://en.wikipedia.org/wiki/Linear_circuithttp://en.wikipedia.org/wiki/Linear_circuithttp://en.wikipedia.org/wiki/Hysteresishttp://en.wikipedia.org/wiki/Parasitic_capacitancehttp://en.wikipedia.org/wiki/Resonant_circuithttp://en.wikipedia.org/wiki/Capacitancehttp://en.wikipedia.org/wiki/Electrical_resistancehttp://en.wikipedia.org/wiki/Faraday%27s_law_of_inductionhttp://en.wikipedia.org/wiki/Henry_(unit)http://en.wikipedia.org/wiki/Inductancehttp://en.wikipedia.org/wiki/Electric_currenthttp://en.wikipedia.org/wiki/Magnetic_fieldhttp://en.wikipedia.org/wiki/Magnetic_fieldhttp://en.wikipedia.org/wiki/Energyhttp://en.wikipedia.org/wiki/Electronic_componenthttp://en.wikipedia.org/wiki/Passive_component