Ultrasonic Motion Detector
Content
ULTRASONIC MOTION DETECTOR
The ultrasonic motion detector is a project that uses an ultrasonic sensor as its base to detect movement or moving object in
small places. It is design to be a low cost ultrasonic motion detector. The transmitter sensor use to generate signal in that
area. When the signal is block by moving or movement the receiver will gets the signal and amplifies the signal using
transistor. The transistor is use as an amplifier to the receiver circuit. The Led and buzzer in the circuit use to see if there is
movement detect by the sensor. The relay use to trigger another circuit when there is movement detects. The signal
generate by the sensor is about ±40khz. This is a fully hardware design project plus it is built to be a portable ultrasonic
motion detector.
INTRODUCTION
Human, animal or anything can produce sound. This sound is creating by the physical movement whether the movement is
fast or slow depends on the medium that create the sound. Eventually these movements can be detected by using an
ultrasound sensor. Ultrasonic sound waves are sound waves that are above the range of human hearing and, thus, have a
frequency above about 20,000 hertz. Any frequency above 20,000 hertz may be considered ultrasonic.
An ultrasonic sensor typically comprises at least one ultrasonic transducer which transforms electrical energy into sound
and, in reverse, sound into electrical energy, a housing enclosing the ultrasonic transducer or transducers, an electrical
connection and, optionally, an electronic circuit for signal processing also enclosed in the housing. Ultrasonic sensors have
typically been used in applications such as detecting and identifying solid objects, measuring the shape and orientation of a
work piece, detecting possible collisions between objects to avoid the collisions, room surveillance, flow measurement, and
determining a type of material by measuring the absorption of sound.
By combining parts of electronic to the ultrasonic sensor it become an ultrasonic motion detector. A motion detector is an
electronic device that detects the physical movement in a given area and transforms motion into an electric signal. The
motion detector may be electrically connected to devices such as security, lighting, audio 2 alarms. Motion sensors are
used in a wide variety of applications. Motion detectors are mainly used in for security systems.
Now days in the market there are many kind of ultrasonic motion detector sell, basically this project is to design an ultrasonic
motion detector use to detect physical movement of human, animal, or anything that move. The design is to improving the
use of sensor in detecting motion. Also to reduce the cost to built an ultrasonic motion detector
The circuit consists of the following major blocks
1. Transmitter
2.
3.
4.
5.
6.
7.
8.
Receiver
Transistor Amplifier Circuit
Opamp Amplifie
Opamp Comparator
Pi Filter
Schmitt Trigger
Darlington pair Amplifier
1. Transmitter
The transmitter circuit consists of mainly an astable multivibrator circuit using IC 4093. The capacitor and resistor values are
adjusted to obtain a frequency of 40 kHz which is fed to the ultrasonic transmitter. The transmitter produces ultrasonic
waves of 40 kHz frequency which travel around the room, get reflected and fall on the receiver.
2. Receiver
The receiver is an ultrasonic transducer. After transmission, the signal gets reflected from the surroundings. This signal is
received at the receiver transducer and is then sent to process for the presence of motion.
3. Transistor Amplifier Circuit
The first part of the receiver circuit consists of an amplifier section using a BC547. The ultrasonic waves from the transmitter
get reflected and fall on the receiver. The receiver is connected to an amplifier circuit having a gain of 20. The amplitude of
waves falling on the receiver is very small, the amplifier amplifies the noise.
4. Opamp Amplifier
The LM741 series are general purpose operational amplifiers which feature improved performance over industry standards
like the LM709. They are direct, plug-in replacements for the 709C, LM201, MC1439 and 748 in most applications. The
amplifiers offer many features which make their application nearly foolproof: overload protection on the input and output, no
latch-up when the common mode range is exceeded, as well as freedom from oscillations. This is the second stage of the
amplifier section. This part further amplifies the noise received by the ultrasonic receiver. This also integrate the output of the
amplifier
5. Opamp Comparator
One input consists of the shifted, negative clipped amplified output of the Opamp amplifier and the positive clipped amplified
output. The output of the comparator is by default high and when the positive clipped portions exceed the negative clipped
part due to noise, the Opamp inverts.
6. Pi-filter
The capacitor-input filter, also called pi filter due to its shape that looks like the Greek letter pi, is a type of electronic
filter. The pi-filter converts the fluctuating ac noise into dc and feeds into the Opamp comparator
7. Schmitt trigger
The next part of the receiver circuit is the Schmitt trigger. The Schmitt trigger is a comparator application which switches the
output negative when the input passes upward through a positive reference voltage. It then uses negative feedback to
prevent switching back to the other state until the input passes through a lower threshold voltage, thus stabilizing the
switching against rapid triggering by noise as it passes the trigger point. In this circuit the motion caused by the object
causes distortion at the receiver output. The comparator output is by default high. When the noise levels detected are
substantially high, the comparator inverts itself and the trigger is triggered. The output is fed to a Darlington pair.
8. Darlington pair
This is a very high current gain section which when turned on by the trigger from the Schmitt trigger, starts conducting and
the buzzer and led goes on
COMPONENTS LIST
C10 - 100 nF
R1 - 180 KOhm
C12 - 2.2 uF/16V
R2, R12 - KOhm
C13 - 3.3nF
R3, R8 - 47 KOhm
C14 - 47nF
R4 - 3.9 KOhm
TR1, TR2, TR3 - BC547 , BC548
R5, R6, R16 - 10 KOhm
P1 - 10 KOhm trimmer
R7, R10, R12, R14, R17 - 100 KOhm
P2 - 47 KOhm trimmer
R9, R11 - 1 MOhm
IC1, IC2 - 741 OP-AMP
R13, R15 – 3.3 KOhm
IC3 - 4093 C-MOS
C1, C6 - 10uF/16V
R TRANSDUCER 40KHz
C2 - 47uF/16V
T TRANSDUCER 40KHz
C3 - 4.7 pF
D1, D2, D3, D4 - 1N4148
C4, C7 - 1 nF
Technical Specifications C5 - 10nF
Characteristics
C8, C11 – 4.7 uF/16V
Working voltage: 12V DC
C9 - 22uF/16V
Current: 30 mA
WORKING OF THE CIRCUIT
As it has already been stated the circuit consists of an ultrasonic transmitter and a receiver both of which work at the same
frequency. They use ultrasonic piezoelectric transducers as output and input devices respectively and their frequency of
operation is determined by the particular devices in use.
The transmitter is built around two NAND gates of the four found in IC3 which are used here wired as inverters and in the
particular circuit they form a multivibrator the output of which drives the transducer. The trimmer P2 adjusts the output
frequency of the transmitter and for greater efficiency it should be made the same as the frequency of resonance of the
transducers in use. The receiver similarly uses a transducer to receive the signals that are reflected back to it the output of
which is amplified by the transistor TR3, and IC1 which is a 741 op-amp. The output of IC1 is taken to the non inverting input
of IC2 the amplification factor of which is adjusted by means of P1. The circuit is adjusted in such a way as to stay in
balance as long the same as the output frequency of the transmitter. If there is some movement in the area covered by the
ultrasonic emission the signal
that is reflected back to the receiver becomes distorted and the circuit is thrown out of balance. The output of IC2 changes
abruptly and the Schmitt trigger circuit which is built around the remaining two gates in IC3 is triggered. This drives the
output transistors TR1, 2 which in turn give a signal to the alarm system or if there is a relay connected to the circuit, in
series with the collector of TR1, it becomes activated. The circuit works from 9-12 VDC and can be used with batteries or a
power supply.
APPLICATIONS
1.
2.
3.
4.
The motion detector circuit has a number of uses.
As burglar alarm: The circuit can be used as an alarm system in homes, shops and even automobiles. The device is small,
sensitive and has a low cost. This can be used in homes and shops to guard safes and other valuables.
As a people counter device: A people counter is a device used to measure the number and direction of people traversing a
certain passage or entrance per unit time. The resolution of the measurement is entirely dependent on the sophistication of
the technology employed. The device is often used at the entrance of a building so that the total number of visitors can be
recorded. The motion detector can be used in daytime to count the number of people entering a shop by attaching a counter
circuit and can be converted into a burglar alarm at night by minimum modifications.
As High Security Safe Alarm: When integrated with a high security safe it can trigger an alarm even in the event of a minute
movement. Hence it can serve the purpose of handling attempted robberies on high security vaults.
Motion Sensing Camera Trigger: As the name suggests the device can be used to trigger cameras to automatically operate
the presence of motion in surroundings. This can be used in wildlife photography and security cameras.
Mobile Controlled Home Appliances without Microcontroller
Sometimes unfortunately we may forget switch off the appliances while going to the outside and we face the problems to switch off these devices when we are out of
home. To solve these types of problems this article explains you how to design a simple circuit, which will on the devices remotely and devices will off automatically
after the specified time interval. Till now we have seen so many circuits to control the devices or appliances from the remote place but the main advantage of this
circuit is simple because we are not using any microcontroller in this circuit and it uses the components which are easily available in the market. We have already
seen How DTMF Controlled Home Automation System Circuit Works using Microcontroller in the earlier post.
Mobile Controlled Home Appliances Circuit Principle:
The main principle used in this circuit is DTMF communication. DTMF is acronym for Dual-Tone Multi-Frequency. When you make a call to customer care service they
will ask you to press the numbers to provide the appropriate services. If you think about how they are recognizing the pressed number then DTMF comes on the
picture.
If you press the button in your mobile phone then a tone is generated with 2 frequencies. These 2 frequencies of the tone are row and column frequencies of that
particular button. For example if you press the button 1 then a tone generated with the sum of 697 Hz and 1209 Hz. The below table show you the row and column
frequencies of a DTMF keypad.
These generated tones are decoded at switching centre to determine which button is pressed. Now we have to use this DTMF tones to control the devices from
remote area. To decode these DTMF tones at receiver we need to use a DTMF decoder. Decoder IC converts these tones into the digital form. For example if you
press number ‘5’ in mobile keypad then the output of DTMF decoder is ‘0101’.
Circuit Components:
MT8870 DTMF decoder
NE555 timer IC
5V relay
230V, 50 Hz AC motor
BC548 transistors – 2
3.579 MHz crystal
Pot – 4.7M ohm
2.5mm audio jack
red LED
Electrolytic capacitor – 470uF
1n4007 Diodes – 5
0.1uF Ceramic capacitors – 3
Resistors (1/4 watt) – 150k, 1k, 390k, 10k, 100k, 2.2k, 1M, 220
Connecting wires
Bread board
Mobile Phone Controlled Home Automation System Design without Microcontroller:
The main components in this circuit are MT8870 DTMF decoder and 555 timer. Here 555 timer operates in monostable mode. When you make a call to the mobile
which is connected at the receiver end, MT8870 IC provides high pulse at 15 th pin after receiving a valid signal. Now if you press 7 from the mobile the output decoder
IC will trigger the 2nd pin of 555 timer. As a result the output at 3rd pin of 555 timer becomes high, so that transistor Q2 starts conducting because of this LED and
device on. The device on time can be varied by varying the Pot RV1 and capacitor C4. The device on time can be calculated using the formula
Time = 1.1 * RV1 * C4 sec.
In the above circuit device become on only when all the outputs of DTMF decoder (pin 11, pin12, pin13 and pin15) are high. To make all the outputs of DTMF decoder
high we need to press number 7 from the dialed mobile.
How to Operate DTMF Controlled Home Automation System without Microcontroller?
1.
Give the connections as per the circuit diagram.
2.
While giving the connections, make sure that there is no common connection between AC and DC supplies.
3.
Solder a two pin connector to the audio jack
4.
Insert the audio jack to the receiver mobile and keep the receiver mobile in auto answer mode.
5.
Receiver mobile should be in general profile and keypad tones should be in sound mode.
6.
Now make a call to the receiver mobile as it is in the auto answer mode it will pick up the call automatically.
7.
When ring stops press number 7 in your mobile, now you can observe that both LED and device will on for some time and switches off.
DTMF Controlled Home Automation System without Microcontroller Circuit Advantages:
We can avoid the wastage of power
We can control the devices from long distances also
DTMF Mobile Controlled Home Appliances Circuit Applications:
1.
Used to control the home appliances
2.
We can control the robot using this technology
3.
This circuit is used to control the water tank motor by setting the on time
Circuit Limitations:
Security is not provided, anyone can control by making a call to the receiver mobile
Number of devices which we can connect to the circuit is limited.
The ultrasonic motion detector is a project that uses an ultrasonic sensor as its base to detect movement or moving object in
small places. It is design to be a low cost ultrasonic motion detector. The transmitter sensor use to generate signal in that
area. When the signal is block by moving or movement the receiver will gets the signal and amplifies the signal using
transistor. The transistor is use as an amplifier to the receiver circuit. The Led and buzzer in the circuit use to see if there is
movement detect by the sensor. The relay use to trigger another circuit when there is movement detects. The signal
generate by the sensor is about ±40khz. This is a fully hardware design project plus it is built to be a portable ultrasonic
motion detector.
INTRODUCTION
Human, animal or anything can produce sound. This sound is creating by the physical movement whether the movement is
fast or slow depends on the medium that create the sound. Eventually these movements can be detected by using an
ultrasound sensor. Ultrasonic sound waves are sound waves that are above the range of human hearing and, thus, have a
frequency above about 20,000 hertz. Any frequency above 20,000 hertz may be considered ultrasonic.
An ultrasonic sensor typically comprises at least one ultrasonic transducer which transforms electrical energy into sound
and, in reverse, sound into electrical energy, a housing enclosing the ultrasonic transducer or transducers, an electrical
connection and, optionally, an electronic circuit for signal processing also enclosed in the housing. Ultrasonic sensors have
typically been used in applications such as detecting and identifying solid objects, measuring the shape and orientation of a
work piece, detecting possible collisions between objects to avoid the collisions, room surveillance, flow measurement, and
determining a type of material by measuring the absorption of sound.
By combining parts of electronic to the ultrasonic sensor it become an ultrasonic motion detector. A motion detector is an
electronic device that detects the physical movement in a given area and transforms motion into an electric signal. The
motion detector may be electrically connected to devices such as security, lighting, audio 2 alarms. Motion sensors are
used in a wide variety of applications. Motion detectors are mainly used in for security systems.
Now days in the market there are many kind of ultrasonic motion detector sell, basically this project is to design an ultrasonic
motion detector use to detect physical movement of human, animal, or anything that move. The design is to improving the
use of sensor in detecting motion. Also to reduce the cost to built an ultrasonic motion detector
The circuit consists of the following major blocks
1. Transmitter
2.
3.
4.
5.
6.
7.
8.
Receiver
Transistor Amplifier Circuit
Opamp Amplifie
Opamp Comparator
Pi Filter
Schmitt Trigger
Darlington pair Amplifier
1. Transmitter
The transmitter circuit consists of mainly an astable multivibrator circuit using IC 4093. The capacitor and resistor values are
adjusted to obtain a frequency of 40 kHz which is fed to the ultrasonic transmitter. The transmitter produces ultrasonic
waves of 40 kHz frequency which travel around the room, get reflected and fall on the receiver.
2. Receiver
The receiver is an ultrasonic transducer. After transmission, the signal gets reflected from the surroundings. This signal is
received at the receiver transducer and is then sent to process for the presence of motion.
3. Transistor Amplifier Circuit
The first part of the receiver circuit consists of an amplifier section using a BC547. The ultrasonic waves from the transmitter
get reflected and fall on the receiver. The receiver is connected to an amplifier circuit having a gain of 20. The amplitude of
waves falling on the receiver is very small, the amplifier amplifies the noise.
4. Opamp Amplifier
The LM741 series are general purpose operational amplifiers which feature improved performance over industry standards
like the LM709. They are direct, plug-in replacements for the 709C, LM201, MC1439 and 748 in most applications. The
amplifiers offer many features which make their application nearly foolproof: overload protection on the input and output, no
latch-up when the common mode range is exceeded, as well as freedom from oscillations. This is the second stage of the
amplifier section. This part further amplifies the noise received by the ultrasonic receiver. This also integrate the output of the
amplifier
5. Opamp Comparator
One input consists of the shifted, negative clipped amplified output of the Opamp amplifier and the positive clipped amplified
output. The output of the comparator is by default high and when the positive clipped portions exceed the negative clipped
part due to noise, the Opamp inverts.
6. Pi-filter
The capacitor-input filter, also called pi filter due to its shape that looks like the Greek letter pi, is a type of electronic
filter. The pi-filter converts the fluctuating ac noise into dc and feeds into the Opamp comparator
7. Schmitt trigger
The next part of the receiver circuit is the Schmitt trigger. The Schmitt trigger is a comparator application which switches the
output negative when the input passes upward through a positive reference voltage. It then uses negative feedback to
prevent switching back to the other state until the input passes through a lower threshold voltage, thus stabilizing the
switching against rapid triggering by noise as it passes the trigger point. In this circuit the motion caused by the object
causes distortion at the receiver output. The comparator output is by default high. When the noise levels detected are
substantially high, the comparator inverts itself and the trigger is triggered. The output is fed to a Darlington pair.
8. Darlington pair
This is a very high current gain section which when turned on by the trigger from the Schmitt trigger, starts conducting and
the buzzer and led goes on
COMPONENTS LIST
C10 - 100 nF
R1 - 180 KOhm
C12 - 2.2 uF/16V
R2, R12 - KOhm
C13 - 3.3nF
R3, R8 - 47 KOhm
C14 - 47nF
R4 - 3.9 KOhm
TR1, TR2, TR3 - BC547 , BC548
R5, R6, R16 - 10 KOhm
P1 - 10 KOhm trimmer
R7, R10, R12, R14, R17 - 100 KOhm
P2 - 47 KOhm trimmer
R9, R11 - 1 MOhm
IC1, IC2 - 741 OP-AMP
R13, R15 – 3.3 KOhm
IC3 - 4093 C-MOS
C1, C6 - 10uF/16V
R TRANSDUCER 40KHz
C2 - 47uF/16V
T TRANSDUCER 40KHz
C3 - 4.7 pF
D1, D2, D3, D4 - 1N4148
C4, C7 - 1 nF
Technical Specifications C5 - 10nF
Characteristics
C8, C11 – 4.7 uF/16V
Working voltage: 12V DC
C9 - 22uF/16V
Current: 30 mA
WORKING OF THE CIRCUIT
As it has already been stated the circuit consists of an ultrasonic transmitter and a receiver both of which work at the same
frequency. They use ultrasonic piezoelectric transducers as output and input devices respectively and their frequency of
operation is determined by the particular devices in use.
The transmitter is built around two NAND gates of the four found in IC3 which are used here wired as inverters and in the
particular circuit they form a multivibrator the output of which drives the transducer. The trimmer P2 adjusts the output
frequency of the transmitter and for greater efficiency it should be made the same as the frequency of resonance of the
transducers in use. The receiver similarly uses a transducer to receive the signals that are reflected back to it the output of
which is amplified by the transistor TR3, and IC1 which is a 741 op-amp. The output of IC1 is taken to the non inverting input
of IC2 the amplification factor of which is adjusted by means of P1. The circuit is adjusted in such a way as to stay in
balance as long the same as the output frequency of the transmitter. If there is some movement in the area covered by the
ultrasonic emission the signal
that is reflected back to the receiver becomes distorted and the circuit is thrown out of balance. The output of IC2 changes
abruptly and the Schmitt trigger circuit which is built around the remaining two gates in IC3 is triggered. This drives the
output transistors TR1, 2 which in turn give a signal to the alarm system or if there is a relay connected to the circuit, in
series with the collector of TR1, it becomes activated. The circuit works from 9-12 VDC and can be used with batteries or a
power supply.
APPLICATIONS
1.
2.
3.
4.
The motion detector circuit has a number of uses.
As burglar alarm: The circuit can be used as an alarm system in homes, shops and even automobiles. The device is small,
sensitive and has a low cost. This can be used in homes and shops to guard safes and other valuables.
As a people counter device: A people counter is a device used to measure the number and direction of people traversing a
certain passage or entrance per unit time. The resolution of the measurement is entirely dependent on the sophistication of
the technology employed. The device is often used at the entrance of a building so that the total number of visitors can be
recorded. The motion detector can be used in daytime to count the number of people entering a shop by attaching a counter
circuit and can be converted into a burglar alarm at night by minimum modifications.
As High Security Safe Alarm: When integrated with a high security safe it can trigger an alarm even in the event of a minute
movement. Hence it can serve the purpose of handling attempted robberies on high security vaults.
Motion Sensing Camera Trigger: As the name suggests the device can be used to trigger cameras to automatically operate
the presence of motion in surroundings. This can be used in wildlife photography and security cameras.
Mobile Controlled Home Appliances without Microcontroller
Sometimes unfortunately we may forget switch off the appliances while going to the outside and we face the problems to switch off these devices when we are out of
home. To solve these types of problems this article explains you how to design a simple circuit, which will on the devices remotely and devices will off automatically
after the specified time interval. Till now we have seen so many circuits to control the devices or appliances from the remote place but the main advantage of this
circuit is simple because we are not using any microcontroller in this circuit and it uses the components which are easily available in the market. We have already
seen How DTMF Controlled Home Automation System Circuit Works using Microcontroller in the earlier post.
Mobile Controlled Home Appliances Circuit Principle:
The main principle used in this circuit is DTMF communication. DTMF is acronym for Dual-Tone Multi-Frequency. When you make a call to customer care service they
will ask you to press the numbers to provide the appropriate services. If you think about how they are recognizing the pressed number then DTMF comes on the
picture.
If you press the button in your mobile phone then a tone is generated with 2 frequencies. These 2 frequencies of the tone are row and column frequencies of that
particular button. For example if you press the button 1 then a tone generated with the sum of 697 Hz and 1209 Hz. The below table show you the row and column
frequencies of a DTMF keypad.
These generated tones are decoded at switching centre to determine which button is pressed. Now we have to use this DTMF tones to control the devices from
remote area. To decode these DTMF tones at receiver we need to use a DTMF decoder. Decoder IC converts these tones into the digital form. For example if you
press number ‘5’ in mobile keypad then the output of DTMF decoder is ‘0101’.
Circuit Components:
MT8870 DTMF decoder
NE555 timer IC
5V relay
230V, 50 Hz AC motor
BC548 transistors – 2
3.579 MHz crystal
Pot – 4.7M ohm
2.5mm audio jack
red LED
Electrolytic capacitor – 470uF
1n4007 Diodes – 5
0.1uF Ceramic capacitors – 3
Resistors (1/4 watt) – 150k, 1k, 390k, 10k, 100k, 2.2k, 1M, 220
Connecting wires
Bread board
Mobile Phone Controlled Home Automation System Design without Microcontroller:
The main components in this circuit are MT8870 DTMF decoder and 555 timer. Here 555 timer operates in monostable mode. When you make a call to the mobile
which is connected at the receiver end, MT8870 IC provides high pulse at 15 th pin after receiving a valid signal. Now if you press 7 from the mobile the output decoder
IC will trigger the 2nd pin of 555 timer. As a result the output at 3rd pin of 555 timer becomes high, so that transistor Q2 starts conducting because of this LED and
device on. The device on time can be varied by varying the Pot RV1 and capacitor C4. The device on time can be calculated using the formula
Time = 1.1 * RV1 * C4 sec.
In the above circuit device become on only when all the outputs of DTMF decoder (pin 11, pin12, pin13 and pin15) are high. To make all the outputs of DTMF decoder
high we need to press number 7 from the dialed mobile.
How to Operate DTMF Controlled Home Automation System without Microcontroller?
1.
Give the connections as per the circuit diagram.
2.
While giving the connections, make sure that there is no common connection between AC and DC supplies.
3.
Solder a two pin connector to the audio jack
4.
Insert the audio jack to the receiver mobile and keep the receiver mobile in auto answer mode.
5.
Receiver mobile should be in general profile and keypad tones should be in sound mode.
6.
Now make a call to the receiver mobile as it is in the auto answer mode it will pick up the call automatically.
7.
When ring stops press number 7 in your mobile, now you can observe that both LED and device will on for some time and switches off.
DTMF Controlled Home Automation System without Microcontroller Circuit Advantages:
We can avoid the wastage of power
We can control the devices from long distances also
DTMF Mobile Controlled Home Appliances Circuit Applications:
1.
Used to control the home appliances
2.
We can control the robot using this technology
3.
This circuit is used to control the water tank motor by setting the on time
Circuit Limitations:
Security is not provided, anyone can control by making a call to the receiver mobile
Number of devices which we can connect to the circuit is limited.
