Security
is the primary concern for everyone. This project is a standalone Embedded two
gate interlock control system for toll tax using AT89C51 microcontroller. This
project is useful in all applications where two door interlocking is needed.
Use of embedded technology makes this closed loop feedback control system
efficient and reliable. Micro controller (AT89C51) allows dynamic and faster
control. AT89C51 micro controller is the heart of the circuit as it controls
all the functions.
Two IR
TX – RX pairs are used in this
project to identify the entry or exit of the person. These two IR TX
– RX pairs are arranged each one on two doors.
The TX and RX are arranged face
to face across the door so that the RX should get IR signal continuously.
Initially
the entry gate is closed. Whenever any person comes in front of the entry gate,
the IR RX identifies it since the IR signal gets disturbed. Then the microcontroller
opens the entry gate by rotating the stepper motor. After some delay, the gate
will be closed.
After
the person finishes his task, when he stands near the exit door, the second IR
pair placed at the exit gate detects the vehicle and then the exit gate opens
for the vehicle to leave. The microcontroller closes the gate only after the
vehicle exits out. And again the entry door sensor will be waiting for the next
person to enter. Thus both the entry and exit gates will be locked when a
vehicle is present in between the two gates providing security in all means.
This
project uses regulated 5V, 500mA power supply. Unregulated 12V DC is used for
relay. 7805 three terminal voltage regulator is used for voltage regulation.
Bridge type full wave rectifier is used to rectify the ac out put of secondary
of 230/12V step down transformer.