now u can find me on skype
my skype id is :- nish.infotec
my skype id is :- nish.infotec
Sunday 8 December 2013
Saturday 30 November 2013
Tuesday 19 November 2013
Thursday 14 November 2013
Tuesday 12 November 2013
Nish Infotech
hello friends i start to provide hardware, network and web design solution. if u have any problem related with hardware, network and web site design then contact me.....
contact no :- +91 - 9327351994
email id :- nishinfotech@yahoo.in
contact no :- +91 - 9327351994
email id :- nishinfotech@yahoo.in
Friday 25 October 2013
Monday 17 June 2013
Simple Wire-Break Alarm With Delay
Here is a simple circuit of wire-break alarm that activates after a
delay of 15 to 30 seconds. When the thin-wire loop running across the
entrance door is broken, the alarm sounds after a delay of 15 to 30
seconds, the time period set through VR1. Thus the occupants get
sufficient time to lock the room from the outside and catch the thief.
The circuit uses CD4060, which is a 14-stage ripple-carry binary counter/divider and oscillator. It is wired as a timer here and does not need input pulse for trigger. CD4060 gets activated as soon as the power supply is switched on. Output O13 of CD4060 goes high after the lapse of preset delay set through VR1. Transistor SL100 (T2) is wired as a switch to power the timer section built around CD4060. When the wire loop is closed, transistor T2 does not conduct. So power to the timer circuit is not available and the piezobuzzer does not sound.
On the other hand, when the wire loop is broken by some intruder, transistor T2 conducts to power the circuit and the piezobuzzer sounds after 15 to 30 seconds. IC1 can be reset by connecting the wire loop or interrupting the supply.
The circuit works off regulated 9V-12V. Assemble it on a general-purpose PCB and enclose in a metallic or plastic box of appropriate size. Connect piezobuzzer PZ1 through external wires and complete the installation.
The circuit uses CD4060, which is a 14-stage ripple-carry binary counter/divider and oscillator. It is wired as a timer here and does not need input pulse for trigger. CD4060 gets activated as soon as the power supply is switched on. Output O13 of CD4060 goes high after the lapse of preset delay set through VR1. Transistor SL100 (T2) is wired as a switch to power the timer section built around CD4060. When the wire loop is closed, transistor T2 does not conduct. So power to the timer circuit is not available and the piezobuzzer does not sound.
On the other hand, when the wire loop is broken by some intruder, transistor T2 conducts to power the circuit and the piezobuzzer sounds after 15 to 30 seconds. IC1 can be reset by connecting the wire loop or interrupting the supply.
The circuit works off regulated 9V-12V. Assemble it on a general-purpose PCB and enclose in a metallic or plastic box of appropriate size. Connect piezobuzzer PZ1 through external wires and complete the installation.
Wednesday 6 March 2013
Friday 4 January 2013
Interface dot matrix with 8051
LED dot matrices are very popular means of displaying information as it
allows both static and animated text and images. Perhaps, you have
encountered them at gas stations displaying the gas prices, or in the
public places and alongside highways, displaying advertisements on large
dot matrix panels.
In this experiment, we will discuss about the basic structure of a monochrome (single color) LED dot matrix and its interface with a microcontroller to display static characters and symbols. We will cover the animation stuff in next tutorial. I am using the P89C51RD2(NXP) micro-controller for demonstration, but this technique is applicable to any other microcontrollers that have sufficient I/O pins to drive the LED matrix.
In a dot matrix display, multiple LEDs are wired together in rows and columns. This is done to minimize the number of pins required to drive them. For example, a 8×8 matrix of LED's (shown below) would need 64 I/O pins, one for each LED pixel. By wiring all the anodes together in rows (R1 through R8), and cathodes in columns (C1through C8), the required number of I/O pins is reduced to 16. Each LED is addressed by its row and column number. In the figure below, if R4 is pulled high and C3 is pulled low, the LED in fourth row and third column will be turned on. Characters can be displayed by fast scanning of either rows or columns. This tutorial will discuss the method of column scanning.
The LED matrix used in this experiment is of size 5×7. We will learn how to display still characters in a standard 5×7 pixel format. The figure below shows which LEDs are to be turned on to display the English alphabet ‘A’. The 7 rows and 5 columns are controlled through the microcontroller pins. Now, lets see in detail how it works.
Suppose, we want to display the alphabet A. We will first select the column C1 (which means C1 is pulled low in this case), and deselect other columns by blocking their ground paths (one way of doing that is by pulling C2 through C5 pins to logic high). Now, the first column is active, and you need to turn on the LED's in the rows R2 through R7 of this column, which can be done by applying forward bias voltages to these rows. Next, select the column C2 (and deselect all other columns), and apply forward bias to R1 and R5, and so on. Therefore, by scanning across the column quickly (> 100 times per second), and turning on the respective LED's in each row of that column, the persistence of vision comes in to play, and we perceive the display image as still.
In this experiment, we will discuss about the basic structure of a monochrome (single color) LED dot matrix and its interface with a microcontroller to display static characters and symbols. We will cover the animation stuff in next tutorial. I am using the P89C51RD2(NXP) micro-controller for demonstration, but this technique is applicable to any other microcontrollers that have sufficient I/O pins to drive the LED matrix.
In a dot matrix display, multiple LEDs are wired together in rows and columns. This is done to minimize the number of pins required to drive them. For example, a 8×8 matrix of LED's (shown below) would need 64 I/O pins, one for each LED pixel. By wiring all the anodes together in rows (R1 through R8), and cathodes in columns (C1through C8), the required number of I/O pins is reduced to 16. Each LED is addressed by its row and column number. In the figure below, if R4 is pulled high and C3 is pulled low, the LED in fourth row and third column will be turned on. Characters can be displayed by fast scanning of either rows or columns. This tutorial will discuss the method of column scanning.
The LED matrix used in this experiment is of size 5×7. We will learn how to display still characters in a standard 5×7 pixel format. The figure below shows which LEDs are to be turned on to display the English alphabet ‘A’. The 7 rows and 5 columns are controlled through the microcontroller pins. Now, lets see in detail how it works.
Suppose, we want to display the alphabet A. We will first select the column C1 (which means C1 is pulled low in this case), and deselect other columns by blocking their ground paths (one way of doing that is by pulling C2 through C5 pins to logic high). Now, the first column is active, and you need to turn on the LED's in the rows R2 through R7 of this column, which can be done by applying forward bias voltages to these rows. Next, select the column C2 (and deselect all other columns), and apply forward bias to R1 and R5, and so on. Therefore, by scanning across the column quickly (> 100 times per second), and turning on the respective LED's in each row of that column, the persistence of vision comes in to play, and we perceive the display image as still.
The table below gives the logic levels to be applied to R1 through
R7 for each of the columns in order to display the alphabet ‘A’.
You should have noted that across each row, one pin is sourcing the current for only one LED at a time, but a column pin may have to sink the currents from more than one LED. For example, the column C1 should be able to sink the currents from 6 LED's while displaying the alphabet ‘A’. A microcontroller’s I/O pin cannot sink this much of current, so external transistor arrays are required. I am using ULN2003A IC which has seven built-in Darlington transistor arrays (see below). The inputs of ULN2003A are active high. This means the input pins must be supplied with logic high in order to bring the corresponding output pins to ground. The schematic of the Darlington transistor array inside the ULN2003A chip is shown below.
In my project i have used transistors as drivers since ULN ic was not available to me during the project.
project images in RND-KC labs:-
You should have noted that across each row, one pin is sourcing the current for only one LED at a time, but a column pin may have to sink the currents from more than one LED. For example, the column C1 should be able to sink the currents from 6 LED's while displaying the alphabet ‘A’. A microcontroller’s I/O pin cannot sink this much of current, so external transistor arrays are required. I am using ULN2003A IC which has seven built-in Darlington transistor arrays (see below). The inputs of ULN2003A are active high. This means the input pins must be supplied with logic high in order to bring the corresponding output pins to ground. The schematic of the Darlington transistor array inside the ULN2003A chip is shown below.
In my project i have used transistors as drivers since ULN ic was not available to me during the project.
project images in RND-KC labs:-
Wednesday 2 January 2013
install xp in 5min
here i will teach you how install xp in 5-12 min
1) Now when ever you start out installing Windows XP you are greeted with a 256 color bit interface with some loading and other tweaking part.
2) When you complete out that 256 color bit part you will be greeted with setting up graphical interface like below now at this time just press Shift + F10
3) Now after your press Shift + F10 at this stage your will see command prompt popping up, now just type taskmgr to open up the task manager.
4) ow in the task manager shift to Processes tab and your will see setup.exe right there like in the image on the right.
5) Just right click on the
6) That’s it everything thing is done now just see how your Windows XP gets installed within 5-12 minutes approx.
1) Now when ever you start out installing Windows XP you are greeted with a 256 color bit interface with some loading and other tweaking part.
2) When you complete out that 256 color bit part you will be greeted with setting up graphical interface like below now at this time just press Shift + F10
3) Now after your press Shift + F10 at this stage your will see command prompt popping up, now just type taskmgr to open up the task manager.
4) ow in the task manager shift to Processes tab and your will see setup.exe right there like in the image on the right.
5) Just right click on the
setup.exe and select the priority to Real time6) That’s it everything thing is done now just see how your Windows XP gets installed within 5-12 minutes approx.
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