LASER SECURITY SYSTEM
Home security using
this project we will use laser for security. A laser
will fall on LDR or Photiode. On other hand detector will give
signal to signal conditioning circuit. We are using 89s52
micorntroller as a brain. 89s52 is 8051 series IC. 89s51 have 8k
byte ROM , 256 byte RAM. We will give output of sensor circuit to
microcontroller ciruit. Microcontroller will give signal to buzzer
and relay drive circuit. Relay drive circuit will switch on / off
is very necessary to protect home using these technologies.
used laser because it covers large area. Defaul laser will fall on
detector. If laser beam will not fall on security system
In this sensor unit it is our choice , how many sensorís we use ,
IN this project we use two sensorís, In this project we use two
electronics circuit with infra red sensorís and fire alarm sensor.
In the infra red sensor. We use ic 555 as a main component. Pin no 4
and pin no 8 is connected to the positive supply. Pin no 1 is
connected to the negative voltage. One capacitor is grounded from
the pin no 5 for noise cancellation. Output is available on the pin
no 3. Sensor is connected to the pin no 2.
In the case of infra red sensor. Pin no 2 is negative bias through
the 33k ohm resistor and pin no is positively biased through the
photodiode. One infra red transmitter l.e.d is focused to the
photodiode . Infra red l.e.d is directly connected to the positive
and negative supply through the 470 ohm resistor..
In normal stage when light is focus on the photodiode then pin no 2
is positively biased photodiode. If pin no 2 is positive then
negative output is available on the pin no 3. Now when any body
interrupt the light then there is no light on the photodiode and
pin no 2 is now gets its voltage from only 33 k ohm resistor. If
pin no 2 is become negative then output is shifted to the pin no
3. when positive output is available on the pin no 3 and with the
help of this voltage NPN transistor is on and npn transistor
provide a negative voltage as a pulse to the microcontroller.
If we connect two sensor as a input to the microcontroller then we
use same circuit with the ic 555 .
Note that microcontroller sense only negative input to the
Pinout and Description
The 2051 is a
low voltage (2.7V - 6V), high performance CMOS 8-bit
microcontroller with 2 Kbytes of Flash programmable and erasable
read only memory (PEROM). This device is compatible with the
industry standard 8051 instruction set and pinout. The 2051 is a
powerful microcomputer which provides a highly flexible and cost
effective solution to many embedded control applications. The
2051 provides the following features:
~ 2 Kbytes of
~ 128 bytes of RAM
~ 15 I/O lines
~ two16-bit timer/counters
~ five vector, two-level interrupt architecture
~ full duplex serial port
~ precision analog comparator
~ on chip oscillator and clock circuitry
In addition, the
2051 is designed with static logic for operation down to zero
frequency and supports two software selectable power saving
modes. The Idle Mode stops the CPU while allowing the RAM,
timer/counters, serial port and interrupt system to continue
functioning. The Power Down Mode saves the RAM contents but
freezes the oscillator disabling all other chip functions until
the next hardware reset.
To learn how to use the 2051
microcontroller, get the Microcontroller Beginner Kit (click
2051 - 24MHz DIP Available
The 2051 can be programmed using a device programmer such as the
PG302 (Click Here).
We also have Projects that use the 2051 Microcontroller.
Intermediate Tutorial Section.
This page last updated on April 7, 2003.
All the input sensor is connected to the pin no 18 and 19. Pin no 18
is connected to the P1.6, and pin no 19 is connected to the P1.7.
pin no 20 is connected to the positive supply. Pin no 1 reset pin.
One capacitor is connected from positive to pin no 1 and one
resistor is grounded from pin no 1. One microswitch is connected
across the capacitor fro manual reset switch.
One buzzer is connected to the pin no 16 ( Port p1.4) this buzzer is
on when circuit sense a input from the input sensorís. .
to on sw
.001 Ķf,0.1 Ķf,0.01Ķf
crystal 11.0592 MHz
speaker 8 ohm
relay 12v 100 ohm
transformaer 6v 500mA
copper clad board
BLOCK DIAGRAM SECURITY SYSTEM
Easy to implement
available in market.