[[wysiwyg_imageupload:1811:]]This project is submitted by Sanoob from Alappuzha
Abstract
The development of renewable energy has been an increasingly critical topic in the 21st century with the growing problem of global warming and other environmental issues. Solar energy is a renewable source of energy that has the capability of providing the energy for all the activities. The second best attractive thing is that there is no environment hazard wastes are produced as its output compared to any other energy sources like coal and petrol.
Our project aims to electrify a small home from the energy generated by solar panels. The solar panel converts sunlight into electrical energy and this electrical energy is stored in a battery. The energy stored is used to light up LEDs provided in the rooms where light is needed. Even though the major intention is lighting, the energy stored can be used to power a radio and a small LED TV. The designing involves, solar panel, battery charge controller, battery, LED drivers and suitable for low power applications. In order to provide maximum efficiency we are using “Maximum Power Point Tracking”(MPPT) algorithm Technique.
LIST OF SYMBOLS, ABBREVATIONS & NOMENCLATURE
1. MPPT –MAXIMUM POWER POINT TRACKING
2. SEPIC- SINGLE ENDED PRIMARY INDUCTANCE CONVERTER
CHAPTER 1:INTRODUCTION
1.1 OBJECTIVE
Our project objective is to electrify a small home using solar energy .The simplified block diagram is shown in the figure.
FIG 1: BASIC BLOCK OF MPPT BASED SOLAR POWERED HOME
The main part of the project is the solar panel. It converts light energy to electrical energy. It provides a dc voltage and is used to charge the battery. The output voltage of solar panel depends on the intensity of light.
The next part of the project is a SEPIC converter. The solar panel provides a higher or a lower voltage than the voltage required to charge up the battery. When a voltage divider is used most of the power will be lost. When a dc-dc converter is used, the voltage can be converted to required voltage. For converting a higher voltage to lower voltage Buck converter and for the conversion of lower to higher voltage Boost converter is used. Consider the battery charging voltage is 14V, the panel voltage varies from 8V to 24V with the light intensity. So a buck-boost or SEPIC converter is required. In the SEPIC converter the input voltage is converted to higher or lower voltage by taking a feedback from the out -put portion .The feedback is taken by measuring the output voltage.
For the charging purpose an algorithm called MPPT algorithm is implemented. It works by measuring the various parameters like panel voltage, panel current, battery voltage and battery current. Consider when the panel supplies 18V and the charging voltage is 14V ,when the ordinary charging process is used, 4V of input will be lost. So by using MPPT algorithm this can be overcome by tracking the maximum current from the panel and thus improving the efficiency.
On looking the out- put voltage, the microcontroller provides a PWM and is used for the step up or step down process. The various loads used in the system are an LED array as light source ,a radio and dc fan .All devices works on dc voltage so we can connect directly to the battery.
1.2 PROBLEM SPECIFICATIONS/NEED OF PROJECT
The problems faced by us are our main feedback. The main problems faced by us are at first we introduced buck convert but we are not able to provide sufficient voltage at low light intensity. Another problem faced is on the switching of MOSFET. Switching is first done by PUSH PULL transistor circuit but its voltage is not able to provide switching. Next problem faced is on the current sensing circuit at first we used high side current sensor whose voltage across it is difficult to measure.
In this century we need a large amount of energy requirements but we are less in energy sources and majorly used natural resource of energy like petroleum and coal sources are at the stage of verdict, at this stage the renewable resources have its importance. By using solar energy we are able to provide energy till the end of universe. Our project can provide electrical energy to a poor family which lies on a remote place where the normal supply of electricity is difficult. Since the system has a large life time it has only the initial buying cost and its maintenance cost is low.
CHAPTER 3: SELECTION OF TECHNOLOGY/SPECIFIC REQUIREMENTS
· MPPT: The project success depends on how efficient is the system. Here in our project when we are going through the articles and internet we came to know about a technology called MPPT by using it we can increase the efficiency to a higher level. Maximum Power Point Tracking, frequently referred to as MPPT, is an electronic system that operates the Photovoltaic (PV) modules in a manner that allows the modules to produce all the power they are capable of. MPPT is not a mechanical tracking system that “physically moves” the modules to make them point more directly at the sun. MPPT is a fully electronic system that varies the electrical operating point of the modules so that the modules are able to deliver maximum available power. Additional power harvested from the modules is then made available as increased battery charge current. MPPT can be used in conjunction with a mechanical tracking system, but the two systems are completely different.
To understand how MPPT works, let’s first consider the operation of a conventional (non-MPPT) charge controller. When a conventional controller is charging a discharged battery, it simply connects the modules directly to the battery. This forces the modules to operate at battery voltage, typically not the ideal operating voltage at which the modules are able to produce their maximum available power. The PV Module Power/Voltage/Current graph shows the traditional Current/Voltage curve for a typical 75W module at standard test conditions of 25°C cell temperature and 1000W/m2 of insolation. This graph also shows PV module power delivered vs. module voltage. For the example shown, the conventional controller simply connects the module to the battery and therefore forces the module to operate at 12V. By forcing the 75W module to operate at 12V the conventional controller artificially limits power production to 53W. Rather than simply connecting the module to the battery, the patented MPPT system in a Solar Boost charge controller calculates the voltage at which the module is able to produce maximum power. In this example the maximum power voltage of the module (VMP) is 17V. The MPPT system then operates the modules at 17V to extract the full 75W, regardless of present battery voltage. A high efficiency DC-to-DC power converter converts the 17V module voltage at the controller input to battery voltage at the output. If the whole system wiring and all was 100% efficient, battery charge current in this example would be VMODULE ¸ VBATTERY x IMODULE, or 17V ¸ 12V x 4.45A = 6.30A. A charge current increase of 1.85A or 42% would be achieved by harvesting module power that would have been left behind by a conventional controller and turning it into useable charge current. But, nothing is 100% efficient and actual charge current increase will be somewhat lower as some power is lost in wiring, fuses, circuit breakers, and in the Solar Boost Charge controller.
FIG 2: MPPT CHARACTERISTICS
· SEPIC: We also used single ended primary inductance converter (SEPIC) to convert the varying input voltage to desired voltage level. SEPIC has advantage compared to other converters like BUCK, BOOST and BUCK-BOOST converter is that it can convert both low level voltage and high level voltage to desired voltage level and it has a non inverted output. In SEPIC the output voltage can be controlled by the PWM switching provide by the controller IC.
PHOTOVOLTAIC EFFECT: A solar cell is a semiconducting device that absorbs light and converts it into electrical energy. The p n junction silicon cell consists of moderately p doped base substrate and a thin heavily n doped top layer. Thin metal contacts on the surface and a plain metal layer on the back connect this photovoltaic element to the load.
FIG 3: STANDARED P-N JUCTION SOLAR CELL
If exposed to radiation, electron hole pairs are created by photons with an energy greater than the band gap energy of the semiconductor. This is called photovoltaic effect. The newly created charge carriers in the depletion region are separated by the existing electric field. This leads to a forward bias of the p n junction and builds up a voltage potential called the photo voltage. As soon as a load is connected to a cell, this voltage will cause a current to flow through the load.
CHAPTER 4: FEASIBILITY STUDY
The main purpose of feasibility study is to select the best system from group of similar systems, which will work in the environment that can be afforded. Typical criteria for feasibility of a product are accuracy, control easiness, easiness to set up manually and its total cost, which is both its initial cost and maintenance cost. Feasibility of our project is mainly classified into,
· Technical Feasibility.
· Economic Feasibility.
· Operational Feasibility.
Technical Feasibility.
The tracking of maximum charging current from solar panel is based on the embedded program written on the PIC microcontroller which can be erased and used if any correction is to made on that. The program is written on high level language so it became ease to write program.
Economic Feasibility
The project aims mainly on poor families so it must be economically feasible. The costlier part of our project is solar panel which will cost about 160 Rs per watt, now days the government is providing subsidies for buying solar panels. So our project becomes economically feasible.LED array is used for the lighting purpose so it became lifelong and efficient which will decrease the usage of current from the battery .Hence we can use a low cost battery for the use.
Operational Feasibility
User having a minimum knowledge can set up in his house. The only thing he has to look is the position of the solar panel. It should be placed on an unshaded region. The loads attached to battery can be controlled by simple on off switches. Loads are automatically shut off during the time of low voltage level in the battery. These all things make our project feasible for a common man.
CHAPTER 5: SOFTWARE & HARDWARE REQUIRMENT
5.1 SOFTWARES:
Apart from all this there is also a software issue, it means that as all embedded system needs some operating system, but for small purpose our program serve as an operating system, to write our program and make its hex code and it in the microcontroller we use mainly following two software
Proteus
- Or CAD
- Micro -C
1. Proteus:
PCB design combines the ISIS schematic capture and ARES PCB layout to provide a powerful, integrated and easy to use suite of tools for professional PCB design. All proteus PCB design products include an integrated shape based auto router and a basic SPICE simulation capability as standard. More advanced routing modes are included in proteus PCB design Level 2 and higher whilst simulation capabilities can be enhanced by purchasing the advanced simulation option and micro controller simulation capabilities
2.OrCAD:
This is one of the most powerful tools to design a circuit. In this we can place our circuit components and can be simulated. It has mainly two components
1. Capture CIS
2. Layout Plus
These two are the main part of this in the Capture CIS we usually design our circuit and place the component which is further used to create the NetList.
3. Micro-C
The mikroC PRO for PIC is a powerful, feature-rich development tool for PIC microcontrollers. It is designed to provide the programmer with the easiest possible solution to developing applications for embedded systems, without compromising performance or control. PIC and C fit together well: PIC is the most popular 8-bit chip in the world, used in a wide variety of applications, and C, prized for its efficiency, is the natural choice for developing embedded systems. mikroC PRO for PIC provides a successful match featuring highly advanced IDE, ANSI compliant compiler, broad set of hardware libraries, comprehensive documentation, and plenty of ready-to-run examples
5.2HARDWARE
5.2.1 SOLARPANEL
Block Diagram of Hardware
FIG 5 : SOLAR CELLPhotovoltaic cells are devices that absorb sunlight and convert that solar energy into electrical energy. Solar cells are commonly made of silicon, one of the most abundant elements on Earth. Pure silicon, an actual poor conductor of electricity, has four outer valence electrons that form tetrahedral crystal lattices.
When photons (sunlight) hit a solar cell, its energy frees electron-holes pairs. The electric field will send the free electron to the N side and hole to the P side. This causes further disruption of electrical neutrality, and if an external current path is provided, electrons will flow through the path to their original side (the P side) to unite with holes that the electric field sent there, doing work for us along the way. The electron flow provides the current, and the cell’s electric field causes a voltage. With both current and voltage, we have power, which is the product of the two. By wiring solar cells in series, the voltage can be increased; or in parallel, the current. Solar cells are wired together to form a solar panel. Solar panels can be joined to create a solar array
I-V CHARACHTERISTIC OF SOLAR PANEL
Figure below shows the typical characteristics of a solar panel. Isc is a short-circuit current that flows through the panel when the panel is short circuited. It is the maximum current that can be obtained from the panel. Voc is the open-circuit voltage at the terminals of the panel. Vmp and Imp are the voltage and current values at which maximum power can be obtained from the panel. As the sunlight reduces the maximum current (Isc) which can be obtained, the maximum current from the panel also reduces.
FIG 6: VI CHARA OF SOLAR PANEL
5.2.2 BATTERY
In a photovoltaic power supply system, batteries are used as an energy buffer. This buffer is necessary because the sun is not consistently available due to a variety of factors: the weather, time of the day, and for vehicles rapidly changing insulations due to vehicle motion. Using the batteries to store the electrical power from the solar panels in the form of chemical energy makes the generated
Energy readily available whenever it is needed, independent of the current weather Conditions and time.
FIG 7: 12V 7Ah, BATTERY
5.2.3. CONTROLLER
PIC MICROCONTROLLER 16F873A 
FIG8: MICROCONTROLLER
The microcontroller pic16f873 is a 28 pin package. It has 35 instruction set and 5 input channel 10bit analog to digital module. It operates in frequency of dc 20 MHz and three input output ports. The microcontroller used to provide PWM signal to SEPIC circuit. The microcontroller also interfaced with the LCD module and the MPPT algorithm is programmed on microcontroller.
5.2.4. SEPIC CONVERTER
Single-ended primary-inductor converter (SEPIC) is a type of DC-DC converter allowing the electrical potential (voltage) at its output to be greater than ,less than or equal to that at its input ; the output of the SEPIC is controlled by the duty cycle of the control transistor.
A SEPIC is a similar to a traditional buck-boost converter, but has advantages of having non-inverted output (the output voltage is of the same polarity as the input voltage), the isolation between its input and output (provided by a capacitor in series), and true shutdown mode: when the switch is turned off, its output drops to 0 V.
FIG 9: SEPIC CONVERTER BASIC CIRCUIT
The schematic diagram for a basic SEPIC is shown in Figure 5. As with other switched mode power supplies (specifically DC-to-DC converters), the SEPIC exchanges energy between the capacitors and inductors in order to convert from one voltage to another. The amount of energy exchanged is controlled by a switch S1, which is typically a transistor such as a MOSFET; MOSFETs offer much higher input impedance and lower voltage drop than bipolar junction transistors (BJTs), and do not require biasing resistors (as MOSFET switching is controlled by differences in voltage rather than a current, as with BJTs).
Continuous mode
A SEPIC is said to be in continuous-conduction mode (“continuous mode”) if the current through the inductor L1 never falls to zero. During a SEPIC’ssteady-state operation, the average voltage across capacitor C1 (VC1) is equal to the input voltage (Vin). Because capacitor C1 blocks direct current (DC), the average current across it (IC1) is zero, making inductor L2 the only source of load current. Therefore, the average current through inductor L2 (IL2) is the same as the average load current and hence independent of the input voltage. Looking at average voltages, the following can be written:
VIN = VL1 + VC1 + VL2 ( 5.1)
Because the average voltage of VC1 is equal to VIN, VL1 = ?VL2. For this reason, the two inductors can be wound on the same core. Since the voltages are the same in magnitude, their effects of the mutual inductance will be zero, assuming the polarity of the windings is correct. Also, since the voltages are the same in magnitude, the ripple currents from the two inductors will be equal in magnitude. The average currents can be summed as follows:
ID1 = IL1 ? IL2 (5.2)
When switch S1 is turned on, current IL1 increases and the current IL2 increases in the negative direction. (Mathematically, it decreases due to arrow direction.) The energy to increase the current IL1 comes from the input source. Since S1 is a short while closed, and the instantaneous voltage VC1 is approximately VIN, the voltage VL2 is approximately ?VIN. Therefore, the capacitor C1 supplies the energy to increase the magnitude of the current inIL2 and thus increase the energy stored in L2. The easiest way to visualize this is to consider the bias voltages of the circuit in a d. c. state, then close S1.
FIG10: SEPIC ON CONDITION CIRCUIT
When switch S1 is turned off, the current IC1 becomes the same as the current IL1, since inductors do not allow instantaneous changes in current. The current IL2 will continue in the negative direction, in fact it never reverses direction. It can be seen from the diagram that a negative IL2 will add to the current IL1 to increase the current delivered to the load. Using Kirchhoff’s Current Law, it can be shown that ID1 = IC1 – IL2. It can then be concluded, that while S1 is off, power is delivered to the load from both L2 and L1. C1, however is being charged by L1 during this off cycle, and will in turn recharge L2 during the on cycle. 
FIG 11: SEPIC OFF CONDITION CIRCUIT
Because the potential (voltage) across capacitor C1 may reverse direction every cycle, a non-polarized capacitor should be used. However, a polarized tantalum or electrolytic capacitor may be used in some cases, because the potential (voltage) across capacitor C1 will not change unless the switch is closed long enough for a half cycle of resonance with inductor L2, and by this time the current in inductor L1 could be quite large.
The capacitor CIN is required to reduce the effects of the parasitic inductance and internal resistance of the power supply. The boost/buck capabilities of the SEPIC are possible because of capacitor C1 and inductor L2. Inductor L1 and switch S1 create a standard boost converter, which generate a voltage (VS1) that is higher than VIN, whose magnitude is determined by the duty cycle of the switch S1. Since the average voltage across C1 is VIN, the output voltage (VO) is VS1 – VIN. If VS1 is less than double VIN, then the output voltage will be less than the input voltage. If VS1 is greater than double VIN, then the output voltage will be greater than the input voltage.
5.2.5.POWER SUPPLY
12V provide from battery is converted to 5V for providing Vcc for Microcontroller. Here we are using regulator IC 7805 .
FIG 12:5V POWER SUPPLY
5.2.6CURRENT SENSING
The circuit is used for the low side monitoring of current .Here the voltage difference across the series resistor is amplified and the current through it is measured with the help of microcontroller. Care should be taken that the resistor value should be lower as possible .High resistance values cause the power source voltage to degrade through IR loss.
5.2.7LCDMODULE
FIG 13: LCD 2X 16 DISPLAYS
This is used to display the name of the project and the parameters which we have measured. To do so we are using a LCD panel this is HD44780U compatible series display. It can display in two lines, each line contains 16 characters. So we can say it 16×2 matrix LCD display. It has 8 data lines along with an R/W and RS pins. Which make it work in the either in 4 bit mode and 8 bit mode. The contrast of the display can be controlled by the use of the potentiometer which gives the extent of the brightness. The voltage of the third pin of the LCD used to adjusting contrast. Here we are connected a variable resistor P1 for adjusting voltage of the 3rd pin. The c3 and c7 are used to reject the noise from the supply voltage. The same LCD works as 4 bit interfacing. Here this LCD work as 8bit LCD. So we can connect D0-D7 pins of LCD connected.
FIG 14: LCD INTERFACE
LCD PIN DESCRIPTION
Table 1 : LCD PIN DISCRIPTION
|
PIN
|
SYMBOL
|
DESCRPTION
|
|
1
|
Vss
|
Ground
|
|
2
|
Vcc
|
+5V power supply
|
|
3
|
VEE
|
Contrast adjust
|
|
4
|
RS
|
RS=0 to select command register, RS=1 to select data register
|
|
5
|
R/W
|
R/W=0 for write, R/W=1 for read
|
|
6
|
E
|
Enable
|
|
7
|
DB0
|
The 8-bit data bus
|
|
8
|
DB1
|
The 8-bit data bus
|
|
9
|
DB2
|
The 8-bit data bus
|
|
10
|
DB3
|
The 8-bit data bus
|
|
11
|
DB4
|
The 8-bit data bus
|
|
12
|
DB5
|
The 8-bit data bus
|
|
13
|
DB6
|
The 8-bit data bus
|
|
14
|
DB7
|
The 8-bit data bus
|
|
15
|
VLed
|
Supply for back LED
|
|
16
|
VGnd
|
Ground for Back LED
|
CHAPTER 6: DESIGN SPECIFICATION
6.1. SOLAR PANEL.
“Solar panel” provides varying voltage from 8V to 24V we require the maximum power point for charging the battery .Solar panel is supposed to provide 1A at maximum solar intensity.
6.2. SEPIC
SEPIC is used to provide a maximum current for charging the battery. The output voltage of SEPIC depends on the switching frequency of the PWM signal. The PWM switching is provided from the PIC microcontroller. The switching frequency is 20khz is provided.
6.3. CURRENT & VOLTAGE SENSING
The current sensing is done by taking the voltage difference across the low value resistor. The low value resistor is used in the range of .1ohms .The voltage across the low value resistor is provided across the comparator IC 358. The output from the op-amp is a voltage value ranging from 0 to 5 volt. The voltage to be sensed is taken across the voltage divider and the collected output voltage is provided to ADC of PIC it range from 0 to 5 volt.
6.4. GATE DRIVER CIRCUIT.
The PWM from the PIC is only of 5V with this voltage the switching of the MOSFET is not properly functioned so a transistor circuit is provide to increase the voltage level from lower value that is from 5v to 12V in which the proper switching will be possible.
6.5. LOAD SPECIFICATION
Table 2 : LOAD USED IN OUR PROJECT
|
SLNO:
|
COMPONENT
|
SPECIFICATION
|
|
1
|
DC FAN
|
12V,.18A
|
|
2
|
RADIO
|
12V,.49A
|
|
3
|
LED
|
3.6V,20mA
|
CHAPTER 7: HARDWARE DESIGN
|
FIG 15: DETAILED BLOCK DIAGRAM |
7.2CIRCUIT DIAGRAM
· BATTERY CHARGING CIRCUIT
· CURRENT SENSING CIRCUIT
· MICROCONTROLLER CIRCUIT
· LOAD DRIVING CIRCUIT
7.2.1BATTERY CHARGING CIRCUIT
BATTERY CHARGING CIRCUIT: shown in the circuit diagram tab1.
· Choose a switching frequency, fs
· Calculate Duty cycle
(7.2.1)
Assuming 100% efficiency, the duty cycle D for a SEPIC converter operating in CCM is given by D
· Provide 12V for gate
· Capacitor design.
out ×D)÷(Vripple×0.5×fsw) (7.2.2)
· Inductor Design
7.2.2CURRENT SENSING CIRCUIT
FIG17:CURRENT SENSING
7.2.3MICROCONTROLLER CIRCUIT
Shown in circuit diagram tab2.
7.2.4 LED DRIVER CIRCUIT
FIG 19: LED DRIVER
It is basically derived from a basic step-up switching regulator, which is shown in figure14 .Energy stored in the inductor during the time that transistor Q1 is in the “on” state. Upon turn- off, the energy is transferred in series with Vin to the output filter capacitor and load.
FIG 20: BASIC STEPUP SWITCHING REGULATOR CIRCUIT
This configuration allows the output voltage to be set to any value greater than that of the input by the following relationship:
Vout = Vin (ton/toff) + Vin or Vout = Vin (ton/toff+1) 7.2.4
In our project the battery provides only 12 v, but we require 24 v to light up led lamp. For this purpose we have to convert 12 v to 24 v. so we use a boost led driver circuit for the conversion.
CHAPTER 8: SOFTWARE DESIGN
8.1 ALGORITHM
1. Start
2. Initialize ports of microcontroller , LCD and PWM
3. Track
4. Measure battery voltage and battery current.
5. Display on LCD
6. If panel voltage is changed more than a threshold, track again
7. If battery voltage is less than the lower limit switch of the load.
8. If battery voltage reached maximum, turn off charging
9. Go to line 4.
Track
1. Set PWM to zero
2. Measure panel voltage, battery voltage and battery current.
3. Display on LCD
4. If panel voltage is less than limit, stop charging
5. Save the maximum charging current
6. Increase PWM
7. Continue to line 2 until maximum PWM is reached.
8. Set pwm to maximum current value.
9. Return
8.2 Flow Chart
Flow chart is given in the attachments.
CHAPTER 9: IMPLEMENTATION/ TECHNOLOGICAL DEVELOPMENT
Our project is based on the electrical requirement of a financially poor family living in a remote place this can also been useful for middle class family during the time of power failure. Since the amount of output current from a solar panel depends directly on the amount of light falling on it so the solar panel should be placed on where more intensity of sun light is supposed to fall. In normal case it is placed on the roof of the house. Radio, DC fan and LED lamp should be placed on proper place to provide maximum output. Solar panel is having a glass cover over it so care should be given on placing it.
CHAPTER :10 CONCLUSION
· TESTING AND RESULT
The designed hardware circuitry is implemented on a PCB and the software coding is done in very efficient and fast embedded C language. The entire implementation is checked and it proves our effort of a great success. We believe our project is very suitable for the next generation for solving the electrical energy requirement. The design has to be tested for checking the performance, unless the project is tested positive, nothing has been gained by doing it.
· ENHANCEMENT
We can enhance this project by introducing lens frame in front of the solar panel to concentrate the sun light intensity. By providing a suitable heat sink for the panel we can increase the efficiency of the system. We can use this project in motor vehicles to provide the electrical requirement.
· LIMITATIONS
One of the limitation in our system is that if there is no required amount of light intensity ,that is in rainy days we are not able to provide charging current for the battery. The surface of solar panel should be clean to have maximum efficiency so it is less efficient in desert areas where the dust amount is very high. In order to provide voltage to run high load applications we require a large solar panel, that is the output voltage from a solar panel is directly proportional to its area.The initial cost is very high for the components like solar panel and battery. The voltage drop across the current sensing circuit may reduce the efficiency of the system. The increases in temperature of the solar panel reduce the efficiency. Solar panel provides an appropriate voltage up to 30 degree Celsius.
APPENDIX 1
COMPONENT SPECIFICATION WITH COST
Table 3 COMPONENTS USED
|
SL.NO
|
COMPONENTS
|
SPECIFICATIONS
|
Rupees
|
|
|
1
|
RESISTORS
|
|
|
|
|
|
R11
|
2.2K
|
0.5
|
|
|
|
R12,R14
|
1R
|
0.5
|
|
|
|
R3,R7,R5,R26,R23,R22,R18,R19,R16
|
10K
|
0.5
|
|
|
|
R4,R6,R24,R21
|
1K
|
0.5
|
|
|
|
R15,R25
|
47K
|
0.5
|
|
|
2
|
CAPACITORS
|
|
|
|
|
|
C17,C16
|
.1 µF
|
1
|
|
|
|
C23
|
10MF
|
1
|
|
|
|
C14
|
22PF
|
1
|
|
|
|
C-in
|
47MF
|
1
|
|
|
|
C-out
|
100µF
|
1
|
|
|
|
C12
|
47MF/16V
|
1
|
|
|
|
C11
|
0.1µF
|
1
|
|
|
|
C12-C15
|
22PF
|
1
|
|
|
|
C16
|
0.1µF
|
1
|
|
|
|
C17
|
100MF/16V
|
1
|
|
|
|
U1
|
PIC 16F873A
|
150
|
|
|
|
U2
|
LM358
|
15
|
|
|
|
3
|
IC’s
|
|
|
|
4
|
LCD
|
16×2
|
150
|
|
|
5
|
SOLAR PANEL
|
12V,1A
|
1950
|
|
|
6
|
BATTERY
|
7AH
|
665
|
|
|
7
|
MOSFET
|
IRFZ44
|
15
|
|
|
8
|
DIODE
|
|
|
|
|
|
D1,D3
|
IN4148
|
2
|
|
|
|
D2
|
RED LED
|
3
|
|
|
|
D4
|
GREEN LED
|
3
|
|
|
|
D5,D7
|
IN4007
|
2
|
|
|
9
|
INDUCTOR
|
|
|
|
|
|
L1
|
526 µF
|
2
|
|
|
|
L2
|
526 µF
|
2
|
|
APPENDIX 2
PCB LAYOUT
PCB LAYOUT OF CHARGING CIRCUIT
PCB LAYOUT OF LED DRIVER
Circuit Diagrams
Filed Under: Electronic Projects
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