Monday, 15 July 2013
Thursday, 11 July 2013
Oscilloscope
Definition of Oscilloscope :
Oscilloscope
is an electrical Instrument through which we can observe and measure the
different wave forms and graphically behavior of Electrical Circuits.There
are two types of Oscilloscope one is Analog and second is Digital.In
Analog Oscilloscope we need to perform mathematical calculations to measure the
actual values of Wave form.In Digital
Oscilloscope we no need to perform any Mathematical calculation to measure the
actual values of wave form.Today I
will tell you the detail usage of Analog Oscilloscope.
Basics
of Oscilloscope:
Oscilloscope
shows the 2-Dimensional graphical view. For
2-Dimensional graphical view there are two axis in Oscilloscope one is
X-axis and other is Y-axis. we can adjust the position of wave on X & Y
axis by vertical and horizontal position probes.
X-axis
shows the time period of the current wave form as Time per Division.
Y-axis
shows the Amplitude of voltage of current wave form as Volt per Division.
There
are commonly two basic channels in Oscilloscope. From two different channels we
can observe two different wave forms from two different input sources. For both
channels Time axis is same but Volt axis for both channels are different. The
reason is that time on time per division for both wave is same but the
voltage’s amplitude can be different of both waves.
It will
continue in next lecture………………
PART3
Bootstrap Capacitor Design:
From the application notes of the HIP4081, we studied that the bootstrap capacitor must be greater than the ten times of the gate to source capacitance of the MOSFET used in the bridge.
Qgs = 12.3 nC
Vgs(min)= 2volt
Cgs = Qgs/Vgs = 12.3/2 = 6.15 nF
So bootstrap capacitor > 61.5 nF
We used a value of 200 nF.
part2
A battery with a capacity of 10 amp-hour should be able to continuously supply a current of 10 amp to a load for exactly 1 hour, or 20 amps for 1/2 hour, or 1/3 amp for 30 hours, etc., before becoming completely discharged.
Typical A/H Rating of Some Batteries:
Typical automotive battery: 70 amp-hours @ 3.5 A (secondary cell)
D-size carbon-zinc battery: 4.5 amp-hours @ 100 mA (primary cell)
9 volt carbon-zinc battery: 400 milliamp-hours @ 8 mA (primary cell)
The most common type of battery available is lead acid battery. A lead-acid cell generates around 2 volts. Small batteries contain 6 cells in a container which add together to give 12 volts at the terminals.
The steps to calculate the charger requirement for a battery are
i) Determine the suitable A/H ratting of the battery required according to the load and Backup as well as the charging time required
ii) Determine the recharge time required.
iii).To get the charging current, divide the A/H rating by that time.
iv). Add 20% to allow for the battery inefficiency.
v). If there is any additional battery load current during its charging like control circuit, add it also to the charging current.
vi).Select the next biggest charger in the range
Battery Voltage = 12
Volts Load Required = 700
Watt Efficiency Required = 90%
Total Battery Current = (700/0.9)/12 = 70 Amp
Estimated Additional Current = 1 Amp
Total Battery Output Current = 71 Amp
Battery Charging Current = 0.1 * 71 = 7.1 Amp
Backup Time Required= 2 Hour
A/H Ratting Of Battery = 2 * 71 = 141 A/H
NEXT
block diagram of UPS
AC TO DC CONVERSION
Type of chargers:
i). Ferro-Resonant Charger
They are very bulky because of low frequency magnetic control system in it. They are slowly recharged. Their magnetic field may disturb other components of the equipment.
ii). Linear Charger
They also use low frequency transformer in it to reduce the level of the ac voltage, then a combination of bleeding resistor, series resistor and a capacitor is used to control the current and voltage level of dc output.
iii). Switch Mode Charger
It is a newly technique, it directly rectify ac input, then this dc input is switched with high frequency through transistors and with the help of high frequency transformer, its level is lowered and rectified to desired dc output level
A/H Ratting of the Battery
Before designing the charger stage of the battery, we must see the A/H ratting of the battery, which determines the charger time as well as the backup time with respect to the charging current. The ampere-hour ratting ( A/H ratting ) is the indication of battery energy capacity, it is given by the relation:
A battery with a capacity of 10 amp-hour should be able to continuously supply a current of 10 amp to a load for exactly 1 hour, or 20 amps for 1/2 hour, or 1/3 amp for 30 hours, etc., before becoming completely discharged.
Typical A/H Rating of Some Batteries:
Typical automotive battery: 70 amp-hours @ 3.5 A (secondary cell)
D-size carbon-zinc battery: 4.5 amp-hours @ 100 mA (primary cell)
9 volt carbon-zinc battery: 400 milliamp-hours @ 8 mA (primary cell)
The most common type of battery available is lead acid battery. A lead-acid cell generates around 2 volts. Small batteries contain 6 cells in a container which add together to give 12 volts at the terminals.
Battery Charger Selection:
The steps to calculate the charger requirement for a battery are
i) Determine the suitable A/H ratting of the battery required according to the load and Backup as well as the charging time required
ii) Determine the recharge time required.
iii).To get the charging current, divide the A/H rating by that time.
iv). Add 20% to allow for the battery inefficiency.
v). If there is any additional battery load current during its charging like control circuit, add it also to the charging current.
vi).Select the next biggest charger in the range
Calculations:
Battery Voltage = 12
Volts Load Required = 700
Watt Efficiency Required = 90%
Total Battery Current = (700/0.9)/12 = 70 Amp
Estimated Additional Current = 1 Amp
Total Battery Output Current = 71 Amp
Battery Charging Current = 0.1 * 71 = 7.1 Amp
Backup Time Required= 2 Hour
A/H Ratting Of Battery = 2 * 71 = 141 A/H
NEXT
Tuesday, 9 July 2013
HIGH FREQUENCY SINE WAVE UPS
In conventional inverters which are now a day’s commonly used in Pakistan,
consumer faces many problems relating to their performance. The foremost problem is
their efficiency which is in between 85% to 90%. The efficiency mainly depends upon
the switching frequency of the transformer which is used in DC/AC inverter.
The large size of transformer also make the U.P.S very bulky. It also occupies a
large area which is also not good from the point of view of the customer.
The E.M.F induced in the transformer given by the formula relating its
frequency, area, number of turns and magnetic field to each other is
CLASSIFICATION OF INVERTERS:
Introduction OF INVERTER :
Inverter is device that converts the DC Power into AC power. The voltage and the frequency of the converted AC power can be set to required level depending upon the selection of the transformers and control circuit. AC main is converted into DC through a rectifier circuit and battery is charged than the DC from the battery is converted to AC by an inverter circuitry
Types Of Inverter:
Inverter available in the market are usually provide three types of output
- Square wave
- Modified square wave
- Pure sine wave
Square Wave:
Inverters are first invented using a square wave as the output. Square wave has a large number of problems related to the functionality of the devices as these devices are usually designed to operate for the sine wave. Due to the harsh corner of the square wave it is very harmful for the electrical equipments. Harmonic content of the square is very high that result in the overheat of the electrical equipment. So the inverter use the square wave technology tends to produce a lot of heat due to power loss. Efficiency of the square wave inverter is less. The price of these inverter define the efficiency of the inverter.
Modified Square Wave:
Some alterations made on the hardware of the inverter in order to remove the harsh corner of the square wave. Some time the supplier of the modified square wave inverter use the term modified sine wave in order to increase the demand of the that inverter but in reality it is only the modified square wave . It has better characteristics than the square wave. But the overheat factor is still present that result in the reliability of the equipments. So here is a need to make of sine wave inverter
Pure Sine Wave:
All the home appliances and electrical devices are designed to operate for the sine wave. So there is a need to design a inverter that gives output very close or similar to the sine wave. Our project is also to make a sine wave inverter. It also reduce the noise interferences associated with other inverters. With the pure sine wave inverter our project fully assures that sensitive loads will be powered correctly with no noise interference. Depending upon the switching frequency inverter can be classified as
Low Frequency Inverters
High Frequency Inverters
Switching frequency related to the rate at which the DC is converted to the AC. Low frequency inverter oscillates a DC voltage at 50Hz. The voltage of that inverter is then step up to desire level using a large and heavy transformer. The transformers are iron core shown below
Iron core transformer
High frequency inverter on the other hand use small size transformer. Such high frequency inverter may have large harmonic content near the range of the switching frequency. But the advantage is that these harmonics are high in order than the fundamental frequency 50HZ. So in order to separate these harmonics a low pass filter is use. High frequency inverter use ferrite core transformer shown below
Ferrite core transformer
Sunday, 16 June 2013
CONTROLLED SPY VEHICLE
CONTROLLED SPY VEHICLE
The project
is designed for spy purpose. A wireless audio/video camera is used to transmit
the audio/video signal on computer. The camera is mounted on a vehicle, vehicle
moves in accordance with the command from the computer. The vehicle can also be
moved from a remote control. In world of today high security deployment is
required, and this project will give an idea in acquiring a protected
environment. In future warfare these types of intelligence devices played a
very vital role to achieve their desired targets. A clear of this is the
current spy drones operation of US in Pakistan and Afghanistan.
We have also
used the GPS to get the co-ordinates from the satellite and GSM through which
the GPS co-ordinates will receives on the LCD as well as on the mobile.
The
security or defend of any person, object or any asset is very essential.
Throughout the history steps and measurements are taken for the betterment of
security and to make it as useful and as protective and efficient as possible.
In modern
era sophisticated equipments and tools are used for the defense in face of
spying. Different robots, vehicles, a few nanometer cameras, drones and other
type come into widespread use.
Pakistan is
the only Islamic Nuclear state and there are great threats to its nuclear and
other military assets.
Keeping in
view this background we have designed a spy vehicle, which is a step forward,
and a minute try to spy some targets and to save some precious life where the
spy at that particular (congested) area is difficult.
RF: Radio frequency (RF)
technology is commonly used to transmit and receive information without wires.
A wide variety of electronic devices such as television, radio, and wireless
telephone use radio frequency technology to transmit or receive information. RF
can be used in helping one’s business track inventory and equipment.
1.1
Aim
The aim of
the project is to design a multipurpose R/C robot. This project will produce
utility for the user to remotely monitor enemy activities, the destructed
buildings and such places where it is hard for a human being to make a view
point. After making a view point action can be taken accordingly.
Although we have applied this system to monitor and
control some basic functions more complex functions can be added according to
the requirement.
1.2
Features
·
Patrol the
surrounding with sharp camera–eye.
·
Send video
and data captured to the server wirelessly.
·
Easy
control by a computer Wireless media.
·
Mobile in
all directions with miniature size.
·
Conceal in
camouflage without attracting attention.
·
Can take
appropriate action when needed.
1.3
Applications
·
Typical
applications of the project include.
·
Military
reconnaissance mission.
·
Wireless
security and surveillance in hot spots.
·
Search and
rescue operation.
·
Manoeuvring
in hazardous environment.
·
R/C
soldier.
·
Home
security.
1.4
Requirements
·
Design of
robotic car.
·
Receiver
circuitry.
·
Transmitter
circuitry.
·
Tuning of
wireless video camera.
·
Wireless
transmission of video and control instructions.
·
Remotely
control the direction and position of the robot and perform the specific
action.
Friday, 12 April 2013
ACCESSORIES CONTROL
INDICATION SHOW ON PC
USEING “RF” ATTACH WITH MICROCONTROLLER
INTRODUCTION:
THIS PROJECT IS
TECHNIQUE WHICH USED FOR FOUND THE FAULT IN COMPLEX NETWORK IT IS CIRCUIT WHICH
OPREATE ON RADIO FREQUENCY (RF) THERE ARE TWO PARTS OF THIS PROJECT, ONE IS
TRANSMITTER AND OTHER IS RECIVER. THE TRANSMITTER CONSIST ON INPUT’S STAGES AND
RECIVER IS CONSIST ON 7 SCETION WHICH IS ( RECIVER MODILE, POWER SUPPLY,
DECODER, MICROCONTROLLER, SERIAL COMMUNICATOR, SERIAL PORT, COMPUTER) THIS TRANSMITTER
AND RECIVER WHICH WE USING IN THIS PROJECT HAS 100ft COVERAGE WITH 10%
TOLERANCE OF THE DISTANCE , IT FREQUENCYRANGE IS 30MHZ TO 300MHZ WHICH IS LIES
IN VHF/UHF SPECTRUM. WE CAN USE THIS PROJECT FOR THOSE THINGS WHICH ARE FAR FROM US, BUT THEIR RESPONSE IS
REQUIRED VERY EARLY. THE RECIVER OF THE PROJECT OPTEATE ON +5V DC SUPPLY AND IN RECIVER 89S51 MICROCONTROLLER ARE USED FOR WRITING
THE THOSE STATEMENTS WHICH WE REQUIRED APPER ON YOUER COMPUER IN CASE FAULT OCCURE . IN THE RECIVER THE MAX 232 IS
USED FOR INTERFACE THE SERILLY DATA TO COMPUTER. AT LAST IN THE WINDOWS WE ARE USING HYPER
TERMINAL WITH TYPICAL SETTING, FOR READ THE REQUIRD STATEMENTS.
WE CAN WRITE REQUIRED INSTRUCTIONS
IN THE MICROCONTROLLER WITH THE HELP OF FOLLOWING LANGUAGES.
1- ASSEMBLLY.
2- C
LANGUAGE.
3- OTHER
LANGUAGES.
PROJECT PURPOSE.
BASICALLY THIS PROJECT IS DESING
FOR SAVE THE GOLDEN TIME OF THE MAN. THE FOLLWING EXAMPLE CAN BE CALLER IT’S
IMPORTANTS .
APPLICATIONS OF PROJECT
- THIS CAN BE IN INDUSRIES.
- BANK SECURITY SYSTEM.
- HOUSE SECURITY SYSTEM
BLOCK DIAGRAM OF THE PJOJECT.
TRANSMITTER SECTION:
IN THIS PROJECT THE TRANSMITTER IS
CONSIST ON FOLLOWING INPUT’S WHICH IS ACCOSIATED WITH 4 CHANNAL TRANSMITTER
MODULE.
1- SOUND
SWITCH.
2- SIMPLE
BELL
3- LDR.
4- RAYS
CUTT.
5- 4
CHANNAL TRANSMITTER MODULE.
