Download Infra Red Door Monitor System

ELG4135-Electronics III
Professor: Dr. Riadh Habash
Presentation date: Nov 28th, 2006
Group Members:
Yichen Fan
Gefei Zhou
Zhanglei Song
Infrared Entrance Monitor System
Outline
 Introduction
 System Analysis
 Simulation
Results
 Further Improvement
 Conclusion
Introduction

We design and implement the basic infrared system
 This system can be used in many areas such as:




Door entrance monitoring
Guest/visitor monitoring
Home security
Infrared techniques are widely used in many areas. It
has a wavelength of approximately between 750nm and
1mm.
System Description

The infrared systems contains two parts-transmitter part
and receiver part.



The transmitter part uses an IR led to radiates the infrared signal.
The receiver part uses an IR receiver module to receive the
signal.
The IR led (Light Emitting Diode) is an infrared led which
can produces an infrared wave between 750nm to
950nm.
 The IR receiver module is an receiving device which can
detect an infrared light and produce an inputs to the
receiver.
Overview when the beam is on

The transmitter part will generate a modulated signal to
the IR (Infrared) led through which it can radiates an
infrared signal to the receiver.

The receiver will recognize the radiated signal by the IR
(Infrared) receiver module and make an alternative
square wave voltage (0 and +5V) as the input of the
receiver circuit. This will make the whole circuit works
and the LED will be on which means the signal between
them is connected well.
Overview when the beam is off

When the IR (Infrared) beam between the transmitter
and the receiver is broken, the IR (Infrared) receiver
module will recognize there is no more infrared signal
and it will produce a constant high voltage (+5V) as the
input of the receiver circuit.

This will shut down the whole circuit and the LED will be
off which indicates that the beam between the
transmitter and the receiver is being blocked.
Transmitter Board
Transmitter description

Square-wave oscillators
made by using two 555 timer ICs set up as “astable” multivibrators

Resistors & Capacitors
set the IC frequency

Diodes
create a “symmetrical” output

IR LED
pulsed at 38kHz and transmit the IR beam to receiver
555 Timer Description



Initialize capacitor discharged
Lower comparator sets the FF
Charging through R1
Charge time
Tc = 0.693 * R1 * C


Upper comparator resets the
FF
Discharging through R2
Discharge time
Td = 0.693 * R2 * C

Frequency
F = 1/(Tc +Td) = 1/(0.693* R1+R2)*C)
Simulation
 Output
of IC1 (250Hz)
Simulation (Cont)
 Output
of IC2 (38KHz)
Infrared Entrance Monitor
Receiver
 Block
Diagram
 Circuit Analysis
 Simulation Data Comparison
 Improvement
Block Diagram
Receiver
0-5 5kHz
Square wave
output
Charging
capacitor
IR Beam
Detector
Light ON
Relay On
Receiver
5V DC output
Unable to pass
the capacitor
Light Off
Relay Off
Circuit Analysis
Data Comparison -- XSC1
Data Comparison -- XSC2
Data Comparison – Channel B
Blocked
Data Comparison -- XSC1
Data Comparison -- XSC2
Video of The Simulation Results
Conclusion

We have successfully implemented the circuits
in the multisim as well as the hands work.

The simulation meets the theoretical results and
also it meets the results implemented from the
hands work.

The design can be used for commercial purpose.
Further Improvement for our circuit
 Add
a counter to the relay to counts the
number of people entering the shop or the
number of cars entering the entrance.

Change the values of capacitors or the
input voltage to make the discharging time
shorter or longer depends on what we
need.
References

Iguana Labs, “Oscillators, Pulse Generators, Capacitors and the 555
Timer IC”, http://www.iguanalabs.com/555kit.htm, August 6th, 2004

John Hewes, “Relays”,
http://www.kpsec.freeuk.com/components/relay.htm, 2006

Wikipedia, the free encyclopedia, “Counter”,
http://en.wikipedia.org/wiki/Counter, 31 October 2006

Data sheet, http://pdf1.alldatasheet.com/datasheetpdf/view/5642/MOTOROLA/SN74LS107D.html, 2006
Thank you very much
Especially thank you for the Professor
Habash and the TAs who helping us a lot
on the project.
Questions and Concerns?