2. A
PROJECT ON
PASSWORD BASED CONTROL SYSTEM

3. CONTENTS Main Objective Kit Components Explanation Block Diagram
Working Procedure
Advantages
Applications
Conclusion and Future scope
References

4. HARDWARE REQUIREMENTS: 8051 series Microcontroller, Relay Driver IC,
Relays,
Matrix Keypad,
Crystal,
Resistors,
Capacitors,
Diodes,
LED,
Transformer,
Voltage Regulator,
Lamps.

5. SOFTWARE REQUIREMENTS:
Keil compiler
Language: Embedded C or Assembly

6. Power supply
We used for this as a adapter .

7. Description of power supply
The circuit uses standard power supply comprising of a step-down transformer from 230v to 12v and 4 diodes forming a Bridge Rectifier that delivers pulsating dc which is then filtered by an electrolytic capacitor of about 470microf to 100microF.
The filtered dc being un regulated IC LM7805 is used to get 5v constant at its pin no 3 irrespective of input dc varying from 9v to 14v.
The regulated 5volts dc is further filtered by a small electrolytic capacitor of 10 micro f for any noise so generated by the circuit.
One LED is connected of this 5v point in series with a resistor of 330ohms to the ground i.e. negative voltage to indicate 5v power supply availability.

8. MICROCONTROLLER: A single chip Microcontroller AT89S51
It is a smaller computer
Has on-chip RAM, ROM, I/O ports...
RAM
ROM
I/O Port
Timer
Serial COM Port
Microcontroller
CPU
A single chip

9. Features of AT89S51/52: Compatible with MCS®-51 Products
8K Bytes of In-System Programmable (ISP) Flash Memory
Endurance: 10,000 Write/Erase Cycles
4.0V to 5.5V Operating Range
Fully Static Operation: 0 Hz to 33 MHz
256 x 8-bit Internal RAM
32 Programmable I/O Lines
Three 16-bit Timer/Counters
Full Duplex UART Serial Channel
Interrupt Recovery from Power-down Mode
Watchdog Timer
Dual Data Pointer

10. PIN DIAGRAM OF AT89S51:
40 Pin IC
4 Ports
32 Programmable I/O Lines

11. Special Microcontroller Features:
100,000 erase/write cycle Enhanced Flash program memory typical.
1,000,000 erase/write cycle Data EEPROM memory typical.
Data EEPROM Retention > 40 years.
Self-reprogrammable under software control.
In-Circuit Serial Programming™ (ICSP™) via two pins.
Single-supply 5V In-Circuit Serial Programming.
Watchdog Timer (WDT) with its own on-chip RC oscillator for reliable operation.
Programmable code protection.
Power saving Sleep mode.
Selectable oscillator options.
In-Circuit Debug (ICD) via two pins.

12. Peripheral Features: Timer0: 8-bit timer/counter with 8-bit prescaler.
Timer1: 16-bit timer/counter with prescaler, can be incremented during Sleep via external crystal/clock.
Timer2: 8-bit timer/counter with 8-bit period register, prescaler and postscaler.
Two Capture, Compare, PWM modules
- Capture is 16-bit, max. resolution is 12.5 ns
- Compare is 16-bit, max. resolution is 200 ns
- PWM max resolution is 10-bit
Synchronous Serial Port (SSP) with SPI™ (Master mode) and I2C™ (Master/Slave).
Universal Synchronous Asynchronous Receiver Transmitter (USART/SCI) with 9-bit address detection.
Parallel Slave Port (PSP) – 8 bits wide with external RD, WR and CS controls (40/44- pin only).
Brown-out detection circuitry for Brown-out Reset (BOR).

13. MAIN OBJECTIVE
The project is designed to trip the circuit with the help of a password.
This control system provides a solution , which can ensure the safety of line man.
The system is fully controlled by the 8052 microcontroller (where password is saved initially)and by an IC.

14. Hardware Requirements
Transformer
Bridge Rectifier
Voltage Regulator
Micro Controller
EEPROM
TRIAC
Keypad
LCD screen

15. TRANSFORMER
STEP UP TRANSFORMER
STEP DOWN TRANSFORMER

16. BRIDGE RECTIFIER

17. VOLTAGE REGULATOR
A voltage regulator is an electrical regulator designed to automatically maintain a constant voltage level.

18. MICROCONTROLLER

19. PIN DIAGRAM OF 8052

20. TRIAC
The TRIAC is a three terminal semiconductor device for controlling current.
It is effectively a development of the SCR or thyristor, but unlike the thyristor which is only able to conduct in one direction, the TRIAC is a bidirectional device.

21. KEYPAD
Keypads are the most widely used input devices of the 8052and a basic understanding of them is essential. The keypads are mainly three types:
1) 4*3 keypad
2) 4*4 keypad
3) 4*8 keypad. 
The keypad used in this project is 4*3 keypad.

22. LIQUID CRYSTAL DISPLAY (LCD)
Most common LCDs connected to the microcontrollers are 16x2 and 20x2 displays.
This means 16 characters per line by 2 lines and 20 characters per line by 2 lines, respectively.
The standard is referred to as HD44780U, which refers to the controller chip which receives data from an external source (and communicates directly with the LCD.

23. If an 8-bit data bus is used the LCD will require 11 data lines
LCD BACKGROUND
If an 8-bit data bus is used the LCD will require 11 data lines
(3 control lines plus the 8 lines for the data bus)
The three control lines are referred to as EN, RS, and RW
EN=Enable (used to tell the LCD that you are sending it data)
RS=Register Select (When RS is low (0), data is treated as a command)
(When RS is High(1), data being sent is text data )
R/W=Read/Write (When RW is low (0), the data written to the LCD)
(When RW is low (0), the data reading to the LCD)

24. LCD DISPLAY LCDs are the most widely used output devices of the 8052.
LCD stands for Liquid Crystal Display.
LCD is finding wide spread use replacing LEDs.
They are used for writing different messages on a miniature LCD.

25. BLOCK DIAGRAM

26. KIT DESCRIPTION & REPRESENTATION

28. ADVANTAGES APPLICATIONS It avoids the electrical accidents.
Improves lineman safety.
Easy of operation.
Easy to maintain and repair.
APPLICATIONS
Can be used any where in the substation to trip the circuit.
Most useful to operate in the public areas.

29. CONCLUSION
Security is prime concern in our day-to-day life. Every one wants to be as much as secure as to be possible.
This system provides a new approach to secure the life of a lineman.
The circuit can be tripped without any fail and load can also be controlled when required.

30. FUTURE SCOPE
The project can be interfaced with the GSM modem for the remote control of circuit breaker via SMS. So the circuit breaker can, not only operate from the substation, but also from distance through wireless communication.
SCADA can also be implemented to know where the fault is occurred in the system directly and so a linemen can directly locate the fault location and can rectify it.

32. Any queries?