a reporton "4 channel long range infra red"
TRANSCRIPT
A Term paper report on
“4 CHANNEL LONG RANGE INFRA RED REMOTE CONTROL”
Submitted by
Ms.P.V.Pravinya (Y6EC913)
Mr.P.Naveen Kumar (Y6EC858) Mr.D.Santhosh Kumar (Y6EC888)
Under the esteemed Guidance of
Sri. J.RAVINDRANADH, M.Tech.
Assistant Professor
Department of Electronics & Communication Engineering
R.V.R. & J.C. College of Engineering,
(Affiliated to Acharya Nagarjuna University)
Chandramoulipuram, Chowdavaram
GUNTUR – 522 019, Andhra Pradesh, INDIA-2009-2010
I
R.V.R & J.C COLLEGE OF ENGINEERING
CHOWDAVARAM: GUNTUR-522019
DEPARTMENT OF ELECTRONICS AND
COMMUNICATION ENGINEERING
CERTIFICATE
This to certify that this is a bonafide report of the Term Paper titled
“4 CHANNEL LONG RANGE INFRA RED REMOTE CONTROL” submitted by
P.V.Pravinya ,D.Santhosh Kumar, P.Naveen Kumar towards the paper with code EC453
during 1V/1V B.Tech 1 semester in the academic year 2009-2010.
Signature of the guide: Signature of the HOD:
Sri. J.RAVINDRANADH, M.Tech, Dr.A.SUDHAKAR, M.E, Ph.D,
Assistant Professor. Prof. & Head of theDepartment.
II
ACKNOWLEDGEMENT
We feel great to show our sincere gratefulness to our institution R.V.R & J.C
COLLEGE OF ENGINEERING for providing us with an opportunity to fulfill our cherished
dream to have an exposure as a B.Tech graduate and for building a strong foundation of basic
knowledge in the technical field of ELECTRONICS AND COMMUNICATIONS.
We feel happy to record our sincere respects to our principal, Dr.P.S.SANKAR RAO,
for his valuable suggestions and encouragement while pursuing our study at college campus.
It is a pleasure to show our gratitude towards Dr.A.SUDHAKAR, PROFESSOR &
H.O.D of ELECTRONICS AND COMMUNICATIONS ENGINEERING.
We express our deep sense of gratitude to Mr. J.RAVINDRANADH, Assistant
Professor, our guide,who was all the time behind us motivating and encouraging us to complete
the project in time and for providing us the necessary processions to complete our term paper.
It is pleasure for us to express our thanks to the entire lecturers in our institution and
our friends for being with us in reporting this term paper.
Project associates
P.V.Pravinya (Y6EC913)
P.Naveen Kumar (Y6EC858)
D.Santhosh Kumar (Y6EC888)
III
INDEX
CONTENTS PAGE NOs
ABSTRACT VIII
CHAPTER-1
1. Introduction 1
1.1. Home Appliance 1
1.2. IR Transmission 2
1.3. Transmitter 3
1.4. Receiver 4
1.5. Specific Component Description 4
1.5.1. Voltage Regulator 4
1.5.2. Relays 6
1.5.3. Transformer 7
1.5.4. Diodes and Transistors 7
1.5. Printed Circuit Board(PCB) 8
1.6. Project Description 8
1.6.1. Manufacturing process 8
CHAPTER-2
2. Transmitter 10
2.1. Encoder (DLTx-M145026) 11
IV
2.2. Timer (NE555) 11
2.2.1. Features 12
2.2.2. Applications 12
2.3. Schmitt Trigger (74LS132 OR 74LS00) 12
2.4. 2N2222A 13
2.5. IR LED 13
CHAPTER-3
3. Receiver 15
3.1. IR Sensor module (TSOP1738) 16
3.2. Quad 2 input NAND gate(IC 7400) 18
3.3. Decoder (DLRx-M145027) 18
3.4. IC 4049 20
3.4.1. Features 20
3.5. D-flip flop(IC CD4013) 20
3.6. IN4148 21
3.7. Relays 22
3.8. Receiver power supply 22
3.8.1. Voltage Regulator (IC 7805) 23
CHAPTER-4
4. Application 24
4.1. Ordinary bulb 24
4.2. Motor or Fan 24
V
4.3. Metal detector 24
4.4. Dancing lights (Decoration lights) 25
CHAPTER-5
5. Conclusion 27
REFERENCES 28
VI
LIST OF FIGURES
Figures Page nos.
Fig 1.1. Model diagram of IR transmission 2
Fig 2.1. Block diagram of IR transmitter 10
Fig 2.2. Pin diagram of DLTx encoder 11
Fig 3.1. Block diagram of IR receiver 15
Fig 3.2. Block diagram of IR sensor module 17
Fig 3.3. Pin configuration of 7400IC 18
Fig 3.4. Pin diagram of DLRx decoder 19
Fig 3.5. Connection diagram of CD4013IC 21
Fig 3.6. Circuit diagram of receiver power supply 22
Fig 4.1. Block diagram of metal detector 24
Fig 4.2. Circuit diagram of metal detector 25
Fig 4.3. Circuit diagram of dancing lights 25
VII
ABSTRACT
The main objective of the term paper is to reveal about the infrared
communication between two devices via asynchronous serial communication.
Here we have selected four different 230V AC operated devices controlled by a
handheld remote controller. Remote is called as host and receiver module is called as
device. The entire project is designed using different ICs.
We establish a bi-directional communication between host and device via
synchronous serial communication using IR medium. The different AC operated devices
are connected to simple ON/OFF relays. The host contains three modules: keyboard,
Encoder and IR transmitter. When transmitter and receiver matches the green led glows.
Then Decoder gives a code for switch depression and transmits appropriate position to
the device.
The host is operated by battery i.e., 9V cell. The device consists of three
sections: IR receiver, Decoder, and relay unit. The device receives communication code
from host, accordingly ON/OFF control is performed and the device is operated on +5V,
12V power supply taken from AC mains.
VIII
CHAPTER-1
1. Introduction
1.1. Home Appliance
The new invention of different Home appliance these make Human’s life very
luxury. But now a days everyone is busy with their work. There is chance forget to
switch off the Fans or T.V or other Home appliance. So there is need to control the
different devices. That’s why we choose this Project.
There are different home appliance there just like Fan, T.V, Refrigerator,
Washing Machine, Lamp, Water heater, Decoration light’s, Music system’s, Door
locking etc;
In this term paper we take only four Home appliances. These are Lamp, Fan,
Metal detector and Decoration Light’s.
All the applications are works for DC voltage. If we take AC voltage
application’s instead of DC voltage appliance. The only difference is type of the applied
voltage to the RELAY and applications.
We use a lamp works with 6V supply and a DC motor work’s with 3-13V DC
supply. The metal detector circuit work’s with 9V dc supply. The Decoration light is
simple Astable Multivibrator circuit. The LED’s are connected to the collector of each
transistor. This works on 9V DC power supply.
1
1.2. IR Transmission
Wireless infrared communications refers to the use of free-space propagation of
light waves in the near infrared band as a transmission medium for communication, as
shown in Fig.1.1.
Fig.1.1. Model diagram of IR transmission
The communication can be between one portable communication device and
another or between a portable device and a tethered device, called an access point or base
station. Typical portable devices include laptop computers, personal digital assistants,
and portable telephones, while the base stations are usually connected to a computer with
other networked connections. Although infrared light is usually used, other regions of the
optical spectrum can be used (so the term “wireless optical communications" instead of
“wireless infrared communications" is sometimes used).
Wireless infrared communication systems can be characterized by the
application for which they are designed or by the link type, the simplest link type is the
point-to-point system. There, the transmitter and receiver must be pointed at each other to
2
establish a link. The line-of-sight (LOS) path from the transmitter to the receiver must be
clear of obstructions, and most of the transmitted light is directed toward the receiver.
Hence, point-to-point systems are also called directed LOS systems [1].
The links can be temporarily created for a data exchange session between two
users, or established more permanently by aiming a mobile unit at a base station unit in
the LAN replacement application. The link is always maintained between any transmitter
and any receiver in the same vicinity by reflecting or \bouncing" the transmitted
information-bearing light or rejecting surfaces such as ceilings, walls, and furniture.
In the term paper we used this type of technique. We use 40KHz frequency
transmitter and receiver.
1.3. Transmitter
The transmitter is a combination of different IC’s. These are 4026, NE555,
74LS132. The 4026(DLTX) is encoder chip. It encodes 4-bits of information and serially
transmits this information whenever TE (Transmit Enable pin 14) goes low. This happen
when we hold the push button switch down then pulses transmits via infrared LED at the
frequency of 40 KHz.
The NE555 IC is used to generate the desired frequency of oscillations. Because
DLTX is not capable to produce the desired frequency. For this purpose the 555 timer is
used in astable mode of operation.
The IC 74LS132 is used to combine the data from encoder and output of the 555
timer and transmit via IR LED.
3
1.4. Receiver
This is also combination of different IC’s. In the receiver the IC’s are 7400,
45027,4049,4013,7805.
The IR module receives the signal form transmitter. The IR module is very
robust to noisy signals (like form UV fluorescent lamps or natural light) and has a good
visibility cone. The received signal is very weak so IC 74LS00 is used as buffering that
signal. Simply it boosts the signal and sends to 45027(DLRx).
The DLRx decoder chip receives the signal from 7400 then gives output at pin
numbers 12,13,14,15. This output is not directly applied to relays. Because we need a
latch to latch the output.
The CD4013 is a D-Flip Flop. It is used to latch the output coming from DLRx.
Then it operates the corresponding transistor.
1.5. Specific Component Description
1.5.1. Voltage Regulator
A voltage regulator is an electrical regulator designed to automatically maintain
a constant voltage level.It may use an electromechanical mechanism, or passive or active
electronic components. Depending on the design, it may be used to regulate one or more
AC or DC voltages.
With the exception of shunt regulators, all voltage regulators operate by
comparing the actual output voltage to some internal fixed reference voltage. Any
difference is amplified and used to control the regulation element. This forms a negative
feedback servo control loop. If the output voltage is too low, the regulation element is
commanded to produce a higher voltage. If the output voltage is too high, the regulation
4
element is commanded to produce a lower voltage. In this way, the output voltage is held
roughly constant. The control loop must be carefully designed to produce the desired
tradeoff between stability and speed of response.
The LM78XX series of three terminal regulators is available with several fixed
output voltages making them useful in a wide range of applications. One of these is local
on card regulation, eliminating the distribution problems associated with single point
regulation. The voltages available allow these regulators to be used in logic systems,.
instrumentation,
HiFi, and other solid state electronic equipment. Although designed primarily as
fixed voltage regulators these devices can be used with external components to obtain
adjustable voltages and currents. The LM78XX series is available in an aluminum TO-3
package which will allow over 1.0A load current if adequate heat sinking is provided.
Current limiting is included to limit the peak output current to a safe value. Safe area
protection for the output transistor is provided to limit internal power dissipation. If
internal power dissipation becomes too high for the heat sinking provided, the thermal
shutdown circuit takes over preventing the IC from overheating. Considerable effort was
expanded to make the LM78XX series of regulators easy to use and minimize the number
of external components. It is not necessary to bypass the output, although this does
improve transient response. Input bypassing is needed only if the regulator is located far
from the filter capacitor of the power supply [2]. For output voltage other than 5V, 12V
and 15V the LM117 series provides an output voltage range from 1.2V to 5V.
5
Features
Output current in excess of 1A
Internal thermal overload protection
No external components required
Output transistor safe area protection
Internal short circuit current limit
Available in the aluminum TO-3 package
Voltage Range
LM7805C 5V
LM7812C 12V
LM7815C 15V
1.5.2. Relays
A relay is an electrical switch that opens and closes under the control of another
electrical circuit. In the original form, the switch is operated by an electromagnet to open
or close one or many sets of contacts. It was invented by Joseph Henry in 1835.Because a
relay is able to control an output circuit of higher power than the input circuit, it can be
considered to be, in a broad sense, a form of an electrical amplifier.
In this circuit a 12V magnetic relay is used. In magnetic relay, insulated copper
wire coil is used to magnetize and attract the plunger .The plunger is normally connected
to N/C terminal. A spring is connected to attract the plunger upper side. When output is
received by relay, the plunger is attracted and the bulb glows [3].
6
1.5.3. Tranformer
The transformer is used to convert the high voltage to low voltage or low
voltage to high. The conversion depends upon the type of application. The output
voltage depends upon the number of turns of the winding. It has two windings.
These are called primary winding and secondary winding.
The voltage and number of turns relationship is
V1/V2=N1/N2
In the project we used a step down transformer. This converts 230 AC voltages
to 12 AC voltage. The output (12V AC) of the transformer is connected to the circuit
board.
1.5.4. Diodes and Transistors
There are two types of Diodes are used in the term paper. These are 1N4148 and
1N4007. The 1N4007 is an ordinary Diode which is used for rectifying action. This
means it converts the AC voltage to DC voltage with some ripples. So we use a
capacitive filter for to remove the ripples.
The Diode 1N4148 is Zener Diode. These are connected parallel to the IC’s.
Because these are act as a voltage regulators. This means these are allowed certain
voltage to the ICs other than high voltage is applied these are not pass to the ICs. So these
Diodes protect the ICs. These are operated in reverse bias configuration.
Transistors are most useful devices in this term paper. These are use for the
switching action. Transistors are operated in different modes. Here we use just ON/OFF
7
switch. So we pass the voltage to transistor just enough to cut off the transistor. These are
used in both transmitter and receiver.
1.6. Printed Circuit Board (PCB)
1.6.1. Manufacturing process
It is an important process in the fabrication of electronic equipment. The design
of PCBs (Printed Circuit Boards) depends on circuit requirements like noise immunity,
working frequency and voltage levels etc. High powers PCBs require a special design
strategy. Fabrication process to the printed circuit board will determine to a large extent
the price and reliability of the equipment. A common target aimed is the fabrication of
small series of highly reliable professional quality PCBs with low investment. The target
becomes especially important for customer tailored equipments in the area of industrial
electronics.
The layout of a PCB has to incorporate all the information of the board before
one can go on the artwork preparation. This means that a concept which clearly defines
all the details of the circuit and partly defines the final equipment, is prerequisite before
the actual lay out can start. The detailed circuit diagram is very important for the layout
designer but he must also be familiar with the design concept and with the philosophy
behind the equipment.
1.7. Project Description
In older days we must switch off the any device by hand. If we forget to switch
off the device the device works until we switch off it. Previously mechanical switches are
used. If they key is destroyed there is a problem to repair it and there key strokes are
limited and costly. Due to electronic revolution it is possible to develop different keys
8
like membrane, electromagnetic etc; it is possible to control the device with a certain
distance by using remote. By the implementation of GSM technology we can control the
devices from any ware in world. These are advance technologies in the stream. We take
just a IR transmission and it can be operated from a distance 10m.
The transmitter sends the IR signal to receiver via IR LED. The signal is
combination of a certain code. It is generated by DLTX. It is possible to receive the
signal when we place the transmitter exactly parallel to the receiver IR module. When
these two are match that means transmitter transmits the signal that signal receive by the
receiver. Then a GREEN LED in the receiver glows. Then we push the switches then
corresponding relay on.
In the receiver DRLX is decode the signal and send to the D-Flip Flop. Then it
operates the transistor from this the relay on.
We use DC appliance instead of AC appliance because of easy to construct the
circuit. The only difference is we apply the AC source to the relays and connect the AC
appliance to it. The relays are operated for our line voltages.
9
CHAPTER-2
2. Transmitter
Fig.2.1. Block diagram of IR transmitter
Fig.2.1. shows the transmitter circuit. It mainly uses DLTx encoder chip. It encodes 4 bits
of information and serially transmits this information whenever TE (Transmit Enable pin
14) goes low. This happens when you hold the push button switch down pulses transmits
via infrared LED at the frequency of 40 KHz using the NE555
10
oscillator. In this circuit NE555 used as carry frequency oscillator because DLTx is not
capable to provide 40 KHz frequency. To combine DLTx frequency and NE555
frequency we used 74LS132 and the combined frequency is transmitted via IR LED [3].
2.1. Encoder (DLTx-M145026)
This device is designed to be used as encoder in remote control applications.
The MC145026 encodes nine lines of information and serially sends this information
upon receipt of a Transmit Enable (TE) signal. The nine lines may be encoded with
trinary data (low, high or open) or binary data (low or).The words are transmitted twice
per encoding sequence to increase security.
Fig.2.2. Pin diagram of DLTx encoder
2.2. Timer (NE555)
NE555/SA555 is a highly stable controller of producing accurate timing pulses.
With astable operation, the time delay is controlled by one resistor and one capacitor.
With an astable, the frequency and duty cycle are accurately measured by two external
resistors and one capacitor.
11
2.2.1. Features
(a) High current drive capability (200mA)
(b) Adjustable duty cycle
(c) Temperature stability of 0.005%/’C
(d) Turn off time less than 2 sec
2.2.2. Applications
(a) Precision timing
(b) Pulse generation
(c) Time delay generation
(d) Sequential timing
2.3. Schmitt trigger (74LS132 OR 74LS00):
74LS132 contains four two input NAND gates which accepts standard TTL
input signals and provide standard TTL output levels. They are capable of transforming
slowly changing input signals into sharply defined, jitter free output signals. Additionally,
they have greater noise margin than conventional NAND gates.
Each circuit contains a 2-input Schmitt trigger followed by a Darlington level
shifter and a phase splitter driving TTL totem pole output. The Schmitt triggers uses
positive feedback to effectively speed-up slow input transitions, and provide different
input threshold voltages for positive and negative-going transitions. This hysteresis
between the positive-going and negative-going input thresholds (typically 800mv) is
12
determined internally by resistor ratios and is essentially insensitive to temperature and
supply voltage variations. As long as one input remains at a more positive voltage than
VT+ (MAX), the gate will respond to the transitions of the other input.
2.4. 2N2222A
On characteristics:
ELECTRICAL CHARACTERISTICS-ON CHARACTERISTICS
Forward-Current Transfer Ratio
Ic= 0.1 mAdc, Vce= 10 Vdc 2N2221A, L, UA, UB
2N2222A, L, UA, UB
Ic= 1.0 mAdc, Vce = 10 Vdc 2N2221A, L, UA, UB
2N2222A, L, UA, UB
Ic= 10 mAdc, Vce = 10 Vdc 2N2221A, L, UA, UB
2.5. IR LED
2.5.1. Features
o Photo detector and preamplifier in one package
o Internal band filter for PCM frequency
o Internal shielding against electrical field disturbance
o TTL and CMOS compatibility
o Output active low
o Small size package
13
2.5.2. Special Features
o Supply voltage 5.5 V
o Short settling time after power on
o High envelope duty cycle can be received
o Enhanced immunity against disturbance from energy saving lamps
o B.P.F Center Frequency 38khz
o Peak Emission Wavelength 940nm
14
CHAPTER-3
3. Receiver
Fig.3.1. Block diagram of Receiver
Fig.3.1. shows the receiver circuit. DLRx is a decoder chip .It interprets when
4 bits data received at data bus .To receive the transmitted data ,IR remote control receive
module is used .This module accepts signals that are pulsed at 40 KHz .This is close
15
enough a match for the transmitter’s oscillator frequency at 40 KHz .The IR module is
very robust to noisy signals(like from UV fluorescent lamps) and has a good visibility
cone .In other words ,one don’t have to point the emitter exactly at the module .One can
be slightly off-angled(-45 to +45 degrees)just like a TV remote control .In this circuit IR
module received signal from the transmitter .The received signal is very weak so IC
74LS00 is used as buffering that signal [4].
This signal goes in to DLRx Decoder Chip and the DLRx read that signal and
give output at pin no 12,13,14,15. This output is not ready for driving relay so CD4013
IC is used as T-flip-flop .It latches the output .Transistor T1 to T4 is used as switching
transistor for driving 4 relays.
3.1. IR Sensor module (TSOP 1738)
The TSOP17. – Series are miniaturized receivers for infrared remote control
systems. PIN diode and preamplifier are assembled on lead frame, the epoxy package is
designed as IR filter. The demodulated output signal can directly be decoded by a
microprocessor. TSOP1738 is the standard IR remote control receiver series, supporting
all major transmission codes. Here we use 1738 series, because the output carrier signal is
of 38 KHz frequency. The circuit of this IR module i.e. TSOP1738 is designed in that
way that unexpected output pulses due to noise or disturbance signals are avoided. The
distinguishing mark between data signal and disturbance signal are carrier frequency,
burst length and duty cycle.
The data signal should fulfill the following condition:
(1). Carrier frequency should be close to center frequency of the band pass (e.g.38 KHz).
16
(2). For each burst which is longer than 1.8 ms a corresponding gap time is necessary at
some time in the data stream. This gap time should have at least same length as the burst.
When a disturbance signal is applied to the TSOP1738 it can still receive the data signal.
However the sensitivity is reduced to that level that no unexpected pulses will occur [5].
Some examples for such disturbance signals which are suppressed by the TSOP1738 are
DC light (e.g. from tungsten bulb or sunlight).
Continuous signal at 38 kHz or at any other frequency.
Signals from fluorescent lamps with electronic ballast.
Fig.3.2. Block diagram of IR Sensor module
Normally when no signal is falling on TSOP1738 the output of it will be high .When a
signal of 38 KHz from the remote falls on the TSOP1738 its output goes low. This
output is given as the input to NAND gate, which is followed by the IR sensor module
i.e. TSOP1738.
17
3.2. Quad 2 input NAND gate(IC 7400)
This is a quad 2 input NAND gate. The 14-pin DIP shown to the right is an
example of a 7400 part. The chip contains four two-input NAND gates. Each gate uses
two pins for input and one pin for its output and the remaining two contacts supply Power
(+5 V) and connect the ground. IR module output is given as input to the 1,2 pins of
7400. When the output is low ,i.e. logic ‘0’ is applied as input to NAND gate .So, the
output is taken at the pin 3 and it resulted as high for low level input .That means the
data signal is given to the decoder IC i.e.1 45027 DLRx.
Fig.3.3. Pin configuration of 7400IC
3.3. Decoder (DLRx-M145027)
The M145027 decoder receives the serial stream and interprets five of the
trinary (low, high and open) digits as an address code. Thus 2, 4, 3 addresses are possible
if binary data is used at the encoder, 3, 2 addresses are possible .The remaining serial
information is interpreted as four bits of binary data .The valid transmission output (VT)
goes high on the M145027 when two conditions are met . First, two addresses must be
18
consecutively received (in one encoding sequence) which both match the local address.
Second, the 4-bits of data must match the last valid data received. The active VT
indicates that the information at the data output pins has been updated. The pin diagram
of the M145027 is shown below.
The decoder will receive 9-bit word and will interpret some of the bits as
address code and rest of them as data code .The M145027 DLRx interprets the first five
transmitted bits as address and the last four bits as data. If no errors are received, the
M145027 outputs the four bits data when the transmitter sends the address codes that
match that of the receiver.
A valid transmission output goes high on decoder when it recognizes an
address that matches that of the decoder. All this arrangement is available in 16 pin
package, which is shown in Fig.3.4.
Fig.3.4. Pin diagram of DLRx Decoder
19
3.4. IC 4049
The 4049 IC is a Hex inverter or buffer is constructed with MOS P-channel and
N-channel enhancement mode devices in a single monolithic structure. This
complementary MOS device finds primary use where low power dissipation and/or high
noise immunity is desired. This device provides log c-level conversion using only one
supply voltage, Vcc. The input signal high level [Vih] can exceed the Vcc supply voltage
for logic level conversions. Two TTL/DTL loads can be driven when the devices are used
as CMOS to TTL/DTL converters. The four decoded data bits that are given as input to
this 4049 [5] . It generates desired clock signals according to the data bit code at its
output pins.
3.4.1. Features
(1). High source and sink currents.
(2). High to low level converter.
(3). Supply voltage range=3.0 Vdc to 16 Vdc.
3.5. D- Flip Flop(IC CD4013)
The IC CD4013 is dual D flip-flop is a monolithic complementary MOS
(CMOS) integrated circuit constructed with N- and P-channel enhancement mode
transistors. Each flip-flop has independent data, set, reset, and clock inputs and ``Q'' and
``Q'' outputs. These devices can be used for shift register applications, and by connecting
``Q'' output to the data input, for counter and toggle applications. The logic level present
at the ``D'' input is transferred to the Q output during the positive-going transition of the
20
clock pulse. Setting or resetting is independent of the clock and is accomplished by a
level on the set or reset line respectively. The connection diagram of the IC 4013 is
shown in the Fig.3.5.
Fig.3.5. Connection diagram of IC CD4013
3.6. IN4148
The 1N4148 and 1N4448 are high-speed switching diodes fabricated in planar
Technology, and encapsulated in hermetically sealed leaded glass SOD27 (DO-35)
packages. These are used for high speed switching purpose.
3.6.1. Features
(1). Small glass structure ensures high reliability
(2). Fast switching
(3). Low leakage
(4). High temperature soldering guaranteed:
(5). 250 degrees centigrade/10S/9.5mm leads length at 5 lbs tension
21
3.7. Relays
A relay is an electrical switch that opens and closes under the control of another
electrical circuit. In the original form, the switch is operated by an electromagnet to open
or close one or many sets of contacts. It was invented by Joseph Henry in 1835. Because
a relay is able to control an output circuit of higher power than the input circuit, it can be
considered to be, in a broad sense, a form of an electrical amplifier
In this circuit a 12V magnetic relay is used. In magnetic relay, insulated copper
wire coil is used to magnetize and attract the plunger .The plunger is normally connected
to N/C terminal. A spring is connected to attract the plunger upper side. When output is
received by relay, the plunger is attracted and the bulb glows.
3.8. Receiver power supply
Fig.3.6. Circuit diagram of Receiver power supply
22
3.8.1. Voltage Regulator (IC 7805)
The 7805 provides circuit designers with an easy way to regulate DC voltages to
5V. Encapsulated in a single chip/package (IC), the 7805 is a positive voltage DC
regulator that has only 3 terminals. They are Input voltage, Ground and Output Voltage.
Although the 7805 were primarily designed for a fixed-voltage output (5V), it is
indeed possible to use external components in order to obtain DC output voltages of: 5V,
6V, 8V, 9V, 10V, 12V, 15V, 18V, 20V, 24V. Note that the input voltage must, of course,
be greater that the required output voltage, so that it can be regulated downwards [6].
General Features:
Output Current up to 1A
Output Voltages of 5, 6, 8, 9, 10, 12, 15, 18, 24V
Thermal Overload Protection
Short Circuit Protection
Output Transistor Safe Operating Area Protection
23
CHAPTER-4
4. Applications
4.1. Ordinary bulb
This application is normally used is homes. By using this remote, we can
operate lights without any strain by just pressing the switch regarding that application.
4.2. Motor or Fan
This is also normally used application in homes. This project makes people be
comfortable in operating general appliances at homes.
4.3. Metal detector
Fig.4.1. Block diagram of Metal detector
This circuit most useful for security checking. Metal Detector available in the
market are quite expensive.
This metal detector can be used to detect slightly big size metal objects. It used
a sensing coil. This coil should be kept near metallic objects for detection. Input of circuit
is a weak colpitt’s oscillator R.F. range oscillator. Sensing coil forms parts of tuned
oscillator.
24
COILRF
SECTION
RFAMPLIFIE
R
PIEZOALARM
When coil is brought near metallic object magnetic energy is absorbed and oscillator fails
to work. Then final transistor conducts and buzzer is ac activated. Use a 9 volts battery.
After connecting battery, adjust the 4.7K preset till circuit just stop sounding. The circuit
diagram of the metal detector is shown in figure 4.2.
Fig.4.2. Circuit diagram of Metal detector
4.4. Dancing Lights(Decoration lights)
Fig.4.3. Circuit diagram of Dancing lights
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The model figure is shown in Fig.4.3.
The last application is decoration lights. This is a simple Astable Multivinrator.
The different color LED’s are connected to the each collector of the transistors. The
LED’s glows one after the other. This application used in home as a decoration
purpose.This circuit must operated 9V DC supply.
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CHAPTER-5
5. Conclusions
Hence, we conclude that we can operate any of the appliances in our, office or
any institution using IR remote control. The entire term paper depends on transmitter and
receiver that we used. With remote we can control devices up to 20 feet (7 meters) away.
It operates to a TV remote. This term paper satisfies our objective of infrared
communication between two devices via asynchronous serial communication.
27
REFERENCES
[1] www.datasheetarchieve.com
[2] www.vegakit.com
[3]http://en.wikipedia.org/wiki/List_of_4000_series_integrated_circuits
[4]http://www.nex-robotics.com/products/miscellaneous-ics/tsop1738-infrared-
receiver.html
[5]http://www.circuitstoday.com/category/remote-circuits
[6]http://www.alldatasheet.com/view.jsp?Searchword=M45026
[7]http://www.electronicsforu.com/EFYLinux/circuit/may2005/CI-01_May05.pdf