1. SECURITY ALARM Done by RINKESH KURKURE

2.  This project serves as a detecting mechanism to indicate the presence of an object or person in undetected cases.  This system uses an LED transmitter and LDR sensor unit to identify the arrival of a person  It makes a beep sound using a buzzer.

3.  This is basically a detecting mechanism project.  This system switches on the gate light when surrounding light is HIGH.  It helps a lot in saving electricity.

4.  This circuit has two stages.  Transmitting unit and receiving unit.  Transmitting unit consists of LED  Receiving unit consists of LDR sensor.

6. IC 555 TIMER

7.  An IC 555 working in mono stable mode gives the time delay.  IC 555 is a highly stable controller capable of producing accurate timing pulses.  It can operate with a supply voltage in the range of 4.5 to 18V.

9.  It is a pulse generating circuit.  The duration of this pulse is determined by the RC network connected externally to the 555 timer.  In a stable state, the output of the circuit is approximately zero or a logic-low level.

10.  When external trigger pulse is applied output is forced to go high (» VCC)  At the end of the timing interval, the output automatically drawn back to its low stable state.

12.  It is a two stage switching circuit.  This free running multi-vibrator generates square wave without any external triggering pulse.  It switches back and forth from one state to another.  It remains in each state for a time depending upon the discharging of the capacitive circuit

13. L D R L I G H T D E P E N D E N T R E S I S T O R

14. AAn LDR is a variable resistor. IIts value decreases with increasing incident light intensity. AAnd it conducts when light falls on it.

15.  It can have a wide range of resistance.  In bright light resistance is less than 100Ω & in darkness its excess of 10 MΩ.  The cells are capable of reacting to a broad range of frequencies, including infrared (IR), visible light, and ultraviolet (UV).

16.  When the light source to the semiconductor is interrupted by a person walking through the beam of light, a switch is activated that triggers the alarm. Burglar alarms sometimes have electric eyes that operate on the principle of photoconductivity.

17. In an image u can see that when a light falls on LDR the LED glows it is a basic principle of its working.

18. RELAY

19.  A relay is an electrically operated switch.  It can be used to electrically isolate different parts of a circuit  When electricity flows through a coil, it becomes an electromagnet.  Relays allow one circuit to switch a second circuit which can be completely separate from the first.

20.  The switch's motion (ON and OFF) is controlled by the current flowing to the coil, or not.

21. CIRCUIT DIAGRAM

23.  Home and business owners can now choose a new type of keypad control panel designed to help reduce false alarms.  Newer model alarms have technology to measure the size/weight of the object causing the disturbance so we are able to decide how serious the threat is.  When we use high intensity alarms it turns out to be a domestic as well as security purpose project.

25.  The project provides the detecting mechanism of objects or person at unexpected timings.  It has the advantage of saving of electricity since the bulb glows in the dark only for a short interval of time.  Another main advantage is the height adjusting mechanism which we could implement.

26. ADVANTAGES  High sensitivity  Low cost  Simple construction  Easy to install and maintain  Less power consuming  Requires less space  Reliable

27. Thank You