Repaire your nokia 2700 classic

Hai frnds ..... I had a nokia 2700 classic. And there is a problem with it. The problem was when i turned on it starts usually and after some time it turned off automatically ................. And one of my frnd said that there is a problem with its OS ....... If u have such problem with your nokia 2700 classic ...... Then it is the OS problem. This can be repairs your self by using your pc . 1) you want a data cable (to connect the pc to your phone ) , and nokia pc suit , and a good internet connection , and a power supply to give power to the phone battery. 2) just connect your phone to your pc through data cable. And open nokia pc suit in your pc . 3) then click on the phone update in the pc suit . Then it will download and install the nokia phone updater. 4) Then open the nokia phone updater and select the device. Then it will check for updates . 5) if there is no updates there is option for reinstalling the existing OS. Then select that icon then it will download and reinstall the phone OS. 6) if there is a update just update the phone. It will automatically download and install the needed files . 7) now your phone is repaired..... Warning:::😈- do not turn off the phone while updating the phone. If it happens then the phone will damage totally.......

INTRODUCTION TO MICROCONTROLLERS

A microcontroller (sometimes abbreviated µC, uC or MCU) is a small computer on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals. Program memory in the form of NOR flash or OTP ROM is also often included on chip, as well as a typically small amount of RAM. Microcontrollers are designed for embedded applications, in contrast to the microprocessors used in personal computers or other general purpose applications.
Microcontrollers are used in automatically controlled products and devices, such as automobile engine control systems, implantable medical devices, remote controls, office machines, appliances, power tools, toys and other embedded systems. By reducing the size and cost compared to a design that uses a separate microprocessor, memory, and input/output devices, microcontrollers make it economical to digitally control even more devices and processes. Mixed signal microcontrollers are common, integrating analog components needed to control non-digital electronic systems.
Some microcontrollers may use four-bit words and operate at clock rate frequencies as low as 4 kHz, for low power consumption (single-digit milliwatts or microwatts). They will generally have the ability to retain functionality while waiting for an event such as a button press or other interrupt; power consumption while sleeping (CPU clock and most peripherals off) may be just nanowatts, making many of them well suited for long lasting battery applications. Other microcontrollers may serve performance-critical roles, where they may need to act more like a digital signal processor (DSP), with higher clock speeds and power consumption

Programs

Typically microcontroller programs must fit in the available on-chip program memory, since it would be costly to provide a system with external, expandable, memory. Compilers and assemblers are used to convert high-level language and assembler language codes into a compact machine code for storage in the microcontroller's memory. Depending on the device, the program memory may be permanent, read-only memory that can only be programmed at the factory, or program memory that may be field-alterable flash or erasable read-only memory.
Manufacturers have often produced special versions of their microcontrollers in order to help the hardware and software development of the target system. Originally these included EPROM versions that have a "window" on the top of the device through which program memory can be erased by ultraviolet light, ready for reprogramming after a programming ("burn") and test cycle. Since 1998, EPROM versions are rare and have been replaced by EEPROM and flash, which are easier to use (can be erased electronically) and cheaper to manufacture.
Other versions may be available where the ROM is accessed as an external device rather than as internal memory, however these are becoming increasingly rare due to the widespread availability of cheap microcontroller programmers.
The use of field-programmable devices on a microcontroller may allow field update of the firmware or permit late factory revisions to products that have been assembled but not yet shipped. Programmable memory also reduces the lead time required for deployment of a new product.
Where hundreds of thousands of identical devices are required, using parts programmed at the time of manufacture can be an economical option. These "mask programmed" parts have the program laid down in the same way as the logic of the chip, at the same time.
A customizable microcontroller incorporates a block of digital logic that can be personalized in order to provide additional processing capability, peripherals and interfaces that are adapted to the requirements of the application. For example, the AT91CAP from Atmel has a block of logic that can be customized during manufacture according to user requirements.

Other microcontroller features

Microcontrollers usually contain from several to dozens of general purpose input/output pins (GPIO). GPIO pins are software configurable to either an input or an output state. When GPIO pins are configured to an input state, they are often used to read sensors or external signals. Configured to the output state, GPIO pins can drive external devices such as LEDs or motors.
Many embedded systems need to read sensors that produce analog signals. This is the purpose of the analog-to-digital converter (ADC). Since processors are built to interpret and process digital data, i.e. 1s and 0s, they are not able to do anything with the analog signals that may be sent to it by a device. So the analog to digital converter is used to convert the incoming data into a form that the processor can recognize. A less common feature on some microcontrollers is a digital-to-analog converter (DAC) that allows the processor to output analog signals or voltage levels.
In addition to the converters, many embedded microprocessors include a variety of timers as well. One of the most common types of timers is the Programmable Interval Timer (PIT). A PIT may either count down from some value to zero, or up to the capacity of the count register, overflowing to zero. Once it reaches zero, it sends an interrupt to the processor indicating that it has finished counting. This is useful for devices such as thermostats, which periodically test the temperature around them to see if they need to turn the air conditioner on, the heater on, etc.
A dedicated Pulse Width Modulation (PWM) block makes it possible for the CPU to control power converters, resistive loads, motors, etc., without using lots of CPU resources in tight timer loops.
Universal Asynchronous Receiver/Transmitter (UART) block makes it possible to receive and transmit data over a serial line with very little load on the CPU. Dedicated on-chip hardware also often includes capabilities to communicate with other devices (chips) in digital formats such as I²C and Serial Peripheral Interface (SPI).

BASICS OF ROBOTICS

 

First of all you wanted to know that what is a robot ?

Do you think robots means those machines that can walk or run like humans. If you think like that , it is absolutely false. A robot means a machine that can sense the things and analyse the input and generate the appropriate output

 

The following are  some interesting videos related to robots. 

 

     

 

 

The robots have a input accepting unit or sensor and a programmed circuits that work according to the input accepted and can generate relevant output. And it have another unit that can work according to the output signals that are generated by analyzing circuits.

We can make simple robots like “line following robot “,“obstacle avoiding robots” using microcontroller. It is easy to study microcontroller programming. And you can make simpler robots using simpler microcontroller programs.

FILTER CIRCUITS

The main function of  filters  are to convert  rippled output of rectifier circuit to produce a pure dc signal. The main components in the filter circuits are capacitors and inductors. In filter circuits the capacitors charges when the voltage or current increases and it discharges when the current or voltage decreases. The inductors in the filtering circuits uses its self  induction property  to make the rippled signal into a dc signal. In the case of inductor when the current increases above a certain value then it will induse a current in the opposite direction to the net current so the net current will decrease. When the current decreases below a certain value then the inductor produses a current in the direction of the net current so the net current increases. So by using an inductor in series with the rectifier out put we will get a small rippled signal . 

SHUNT CAPACITOR TYPE FILTER

In this type of filter the output of the rectifier is connected parallel to a capacitor before it is connecting to the load resistor. The capacitor will reduse the ripples by passing ac components through the capacitor that is by continouse charging and discharging of capacitor. The required capacitor is selected by calculating the time constant  that needed for  the filter circuit .

 

 

SERIES INDUCTOR TYPE FILTER

In this type of filter circuit an inductor is connected series to the rectifier output. The self induction property of the inductor reduces the ripples in the signal. The series inductor type filter is normally used with fullwave rectifiers and bridge rectifiers. This type of filters will not use with half wave rectifier because of the low efficiency .

 

L SECTION FILTER

In this type of filters capacitors and inductors are used. The out put of the rectifier is connected parallal to the capacitor and series with the inductor. The parallel capacitor passes the ac components in the output of the rectifier. The series inductor reduces the ripples in the output. This type of filter also known as choke filter

 

 

 

 

 

 

π SECTION FILTER

In this type of filters two capacitor and one inductor is used. The two capacitors are connected parallael to the rectifier output. And the inductor is connected series  in between the parallel capacitors. It is one of the efficient  filter .

 

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RECTIFIERS

the rectifiers are mainly used for rectifying the ac power suppy and it will give a voltage or current that will be in an dc form . These rectifiers are mainly used in almost all electrical devices which needs dc input power supply . The invension of diodes made a big change in the rectification circuits .the diodes mainly used for the rectifiers are rectifier diodes .  There are mainly 3 types of rectifiers .
1) Half wave rectifier
2) center tapped full wave rectifier
3) Bridge rectifier

Half wave rectifier

This is a type of rectifier in which it consist of only one diode . The diode in the circuit acts like a switch . and it will only conduct +ve half cycle or -ve half cycle as per the diode is biased . So that the half wave rectifier only rectifies the one half cycle . so the frequency of the signal remains same . and the diode is connected to a load resistor so that we can take the out put across the resistors .

 

 

Centere tapped rectifier

For this type of rectifier construction we want a center tapped transformer. So that the central terminal in the output side act as a 0 potential . The other two terminal is connected to two diodes and it is connected to a load resistor . The flow of current through the resistor from the two diodes will be in the same direction . The two dides help to rectify the +ve and -ve half cycles .The out put frequency will be twice that of the input frequency .

 

 

Bridge rectifier

It consist of 4 diodes . In this type of rectifiers in one half cycle two diodes will be in forward biase and in the the other half cycle the other two diodes will be in forward biased . And a load resistor is used to take the out put . The out put frequency will be twice that of the input frequency .

 

 

 

 

 

The rectified out put will not be a pure dc there may be some ripples these ripples can be avoided by connecting a filtering circuit in the output side of the rectifiers . And in order to regulate the voltage a voltage regulator which is made of zener diode is placed

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APPLICATIONS OF PIEZOELECTRIC SENSORS

Piezoelectric sensors have proven to be versatile tools for the measurement of various processes. They are used for quality assurance process control and for research and development in many different industries. Although the piezoelectric effect was discovered by pierrie curie in 1880, it was only in the 1950s that the piezoelectric effect started to be used for industrial sensing applications. Since then, this measuring principle has been increasingly used and can be regarded as a mature technology with an outstanding inherent reliability. It has been successfully used in various applications, such as in medical, aerospace, nuclear instrumentation, and as a pressure sensor in the touch pads of mobile phones. In the automotive industry, piezoelectric elements are used to monitor combustion when developing internal combustion engine. The sensors are either directly mounted into additional holes into the cylinder head or the spark/glow plug is equipped with a built in miniature piezoelectric sensor.

The rise of piezoelectric technology is directly related to a set of inherent advantages. The high modulus of elasticity of many piezoelectric materials is comparable to that of many metals and goes up to 1000000 N/m².Even though piezoelectric sensors are electromechanical systems that react to compression, the sensing elements show almost zero deflection. This is the reason why piezoelectric sensors are so rugged, have an extremely high natural frequency and an excellent linearity over a wide amplitude range. Additionally, piezoelectric technology is insensitive to electromagnetic field and radiations , enabling measurements under harsh conditions. Some materials used (especially gallium phosphate) have an extreme stability even at high temperature, enabling sensors to have a working range of up to 1000 °C. Tourmaline shows pyroelectricity in addition to the piezoelectric effect; this is the ability to generate an electrical signal when the temperature of the crystal changes. This effect is also common to piezoceramic materials

HOW TO HIDE FILES & FOLDERS IN JAVA PHONES

it is easy to hide a folder in java phones using .jar .jad technique . 
you should make two folders and in one of the folder you have to place all the files and folders that you want to hide and keep the another folder empty .Rename the folder that contains the files that want to hide as name.jad and Rename the another folder as name.jar  then you can see that the name.jad folder is hidden .If you want to see the hidden file you should rename the name.jar folder to any name .then you can see the name.jad folder on your mobile and you can access the files inside it .