Ultrasonic switchChapter-1

Introduction

1.1 Introduction

Circuit of a new type of remote control switch is described here. This circuit functions with inaudible

(ultrasonic) sound. Sound of frequency up to 20 kHz is audible to human beings. The sound of frequency

above 20 kHz is called ultrasonic sound. The circuit described generates (transmits) ultrasonic sound of

frequency between 40 and 50 kHz. As with any other remote control system this cirucit too comprises a mini

transmitter and a receiver circuit. Transmitter generates ultrasonic sound and the receiver senses ultrasonic

sound from the transmitter and switches on a relay. The ultrasonic transmitter uses a 555 based astable

multivibrator. It oscillates at a frequency of 40-50 kHz. An ultrasonic transmitter transducer is used here to

transmit ultrasonic sound very effectively. The transmitter is powered from a 9-volt PP3 single cell. The

ultrasonic receiver circuit uses an ultrasonic receiver transducer to sense ultrasonic signals. It also uses a

two-stage amplifier, a rectifier stage, and an operational amplifier in inverting mode. Output of op-amp is

connected to a relay through a complimentary relay driver stage. A 9-volt battery eliminator can be used for

receiver circuit, if required.

Ultrasonic sensors (also known as transceivers when they both send and receive) work on a principle

similar to radar or sonar which evaluate attributes of a target by interpreting the echoes from radio or sound

waves respectively. Ultrasonic sensors generate high frequency sound waves and evaluate the echo which is

received back by the sensor. Sensors calculate the time interval between sending the signal and receiving the

echo to determine the distance to an object.Because they are not hard to understand and interfacing them is

easy, ultrasonic sensors are commonly used in robotics. The sensor works in the following ways: A sonic

pulse is emitted from the sensor, then when the pulse bounces off of an object, an echo is returned. The

sensor is able to emit the pulse because of a transducer that converts between sonic, electrical and

mechanical energies.

There are two types of transducers commonly used. The first is called a piezo, and the second is an

electrostatic transducer. Distance is calculated by measuring the time from which the pulse is sent to the

time that the echo is returned.

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Ultrasonic switch1.2 Literature Survey

The present invention relates to a switch module, and more particularly to a wireless switch module, which

can be switch "On" and "Off" via a mechanical means or a wireless digital control signal. In the daily life,

for controlling electrical apparatus or electronic devices on and off, a switch assembly is usually provided to

be coupled with electrical apparatus and the electronic devices, so that a user can operate a switch button

connected to the switch assembly to switch-control electrical apparatus and the electronic devices "On" and

"Off". Due to that there are three problems existing in the prior arts, such as the switch assembly cannot

meet the requirements of wireless control, the wireless switch assembly cannot spatially compatible to the

existed frame and the covering board, and the wireless switch assembly is easier to be blind triggered, the

primary objective of the present invention provides a wireless switch module, which can be switch-

controlled either via a mechanical means, or via a wireless digital control signal. Moreover, in spatial, the

wireless switch module is compatible to the existed frame and the covering board, so as to directly replace

the switch cell(s). The secondary objective of the present invention provides a wireless switch module

comprising a micro control circuit, so as to receive and analyze a wireless digital control signal to

accordingly switch-control the switch circuit.

Another objective of the present invention provides a wireless switch module comprising a wireless signal

transceiver. When a wireless digital control signal cannot be effectively received by a wireless module

located in a remote end, the wireless digital control signal can be received and transmitted by other wireless

switch modules, so as to indirectly transmit the wireless digital control signal to the wireless switch module

located in the remote end. Means of the present invention for solving the problems as mentioned above

provides a wireless switch module being fitted with a frame and a covering board, so as to form a wireless

switch assembly. The wireless switch module comprises at least one switch cell and a control unit. The

switch cell comprises a switch circuit, a switch button and a relay, and the control unit comprises a micro

control circuit coupling with the relay. Within the wireless switch module, the switch button is applied to

switch-control the switch circuit "On" and "Off"; furthermore, the micro control circuit is also applied to

switch-control the switch circuit "On" and "Off" via the relay after receiving and analyzing a wireless digital

control signal. In the preferred embodiment of the present invention, the micro control circuit further

comprises a wireless signal transceiver. Comparing with the conventional switch assembly, the wireless

switch modules as provided in the present invention can be switch-controlled both via the switch button(s)

and the wireless digital control signal; therefore, the present invention can meet the requirement of wireless

control.

Comparing with the existed wireless switch assembly, the wireless switch modules as provided in the

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Ultrasonic switchpresent invention can be directly connected to the existed frame and the covering board, and can be further

electrically connected to a power source and at least one loading via at least one power-in wire and power-

out wire. Therefore, both in spatial and electrical, the wireless switch module is compatible to the existed

frame, covering board, power-in wire(s), power-out wire(s), so that the wireless switch module can directly

replace the conventional switch cell(s). In the present invention, except for receiving the wireless digital

control signal, it is still necessary for the wireless switch module to execute a digital analysis to the wireless

digital control signal, and then switch-control the switch circuit "On" and "Off" in accordance with the

analysis result. Thus, the wireless switch module of the present invention can effectively prevent from being

blind triggered by external wireless interference signals. Nevertheless, in the preferred embodiment of the

present invention, the micro control circuit further comprises a wireless signal transceiver. When a wireless

digital control signal cannot be effectively received by a wireless module located in a remote end, the

wireless digital control signal can be received and transmitted by other wireless switch modules, so as to

indirectly transmit the wireless digital control signal to the wireless switch module located in the remote

end. Therefore, it is obviously that the art of the present invention can control the wireless switch module

located in the remote end via the indirectly transmission method.

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Ultrasonic switch

Chapter-2Objective of study

2.1 Components Details/Description

2.1.1 Resistor

A resistor is a two-terminal passive electronic component which implements electrical resistance as a circuit

element. When a voltage V is applied across the terminals of a resistor, a current I will flow through the

resistor in direct proportion to that voltage. The reciprocal of the constant of proportionality is known as the

resistance R, since, with a given voltage V, a larger value of R further "resists" the flow of current I as given

by Ohm's law:

Resistors are common elements of electrical networks and electronic circuits and are ubiquitous in most

electronic equipment. Practical resistors can be made of various compounds and films, as well as resistance

wire (wire made of a high-resistivity alloy, such as nickel-chrome). Resistors are also implemented within

integrated circuits, particularly analog devices, and can also be integrated into hybrid and printed circuits.

We used resistors of various values listed below-

1. Two resistors of 4.7k.

2. Two resistors of 220k.

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Ultrasonic switch3. Two resistors of 10k.

4. Two resistors of 15k.

5. Single resistors of these values-18k,1k,100k,12k,33k,390k,470k.

6. Variable resistors of 10k,250k.

2.1.2 Capacitor

A capacitor (formerly known as condenser) is a device for storing electric charge. The forms of practical

capacitors vary widely, but all contain at least two conductors separated by a non-conductor. Capacitors

used as parts of electrical systems, for example, consist of metal foils separated by a layer of insulating film.

A capacitor is a passive electronic component consisting of a pair of conductors separated by a dielectric

(insulator). When there is a potential difference (voltage) across the conductors, a static electric field

develops across the dielectric, causing positive charge to collect on one plate and negative charge on the

other plate. Energy is stored in the electrostatic field. An ideal capacitor is characterized by a single constant

value, capacitance, measured in farads. This is the ratio of the electric charge on each conductor to the

potential difference between them.

Capacitors are widely used in electronic circuits for blocking direct current while allowing alternating

current to pass, in filter networks, for smoothing the output of power supplies, in the resonant circuits that

tune radios to particular frequencies and for many other purposes.

We have used following capacitors-

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Ultrasonic switch 680f,0.01uf,0.22uf,0.1uf,560nf.

2.1.3 Potentiometer

A potentiometer (colloquially known as a "pot") is a three-terminal resistor with a sliding contact that forms

an adjustable voltage divider. If only two terminals are used (one side and the wiper), it acts as a variable

resistor or rheostat. Potentiometers are commonly used to control electrical devices such as volume controls

on audio equipment. Potentiometers operated by a mechanism can be used as position transducers, for

example, in a joystick.

Potentiometers are rarely used to directly control significant power (more than a watt), since the power

dissipated in the potentiometer would be comparable to the power in the controlled load (see infinite

switch). Instead they are used to adjust the level of analog signals (e.g. volume controls on audio

equipment), and as control inputs for electronic circuits. For example, a light dimmer uses a potentiometer to

control the switching of a TRIAC and so indirectly control the brightness of lamps.

Symbols:-

Symbol used for Potentiometer In(Europe)

Symbol used for Potentiometer In(U.S.)

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Ultrasonic switch

2.1.4 555 IC as an astable multivibrator

The 555 Timer IC is an integrated circuit (chip) used in a variety of timer, pulse generation and oscillator

applications. The IC was designed by Hans R. Camenzind in 1970 and brought to market in 1971 by

Signetics (later acquired by Philips). The original name was the SE555 (metal can)/NE555 (plastic DIP) and

the part was described as "The IC Time Machine".It has been claimed that the 555 gets its name from the

three 5 kΩ resistors used in typical early implementations, but Hans Camenzind has stated that the number

was arbitrary. The part is still in wide use, thanks to its ease of use, low price and good stability. As of 2003,

it is estimated that 1 billion units are manufactured every year.

The 555 has three operating modes:

Monostable mode: in this mode, the 555 functions as a "one-shot". Applications include timers,

missing pulse detection, bouncefree switches, touch switches, frequency divider, capacitance

measurement, pulse-width modulation (PWM) and so on.

Astable - free running mode: the 555 can operate as an oscillator. Uses include LED and lamp

flashers, pulse generation, logic clocks, tone generation, security alarms, pulse position modulation and

so on.

Bistable mode or Schmitt trigger: the 555 can operate as a flip-flop, if the DIS pin is not connected

and no capacitor is used. Uses include bouncefree latched switches.

An astable multivibrator, often called a free-running multivibrator, is a rectangular-wave generating

circuit. Unlike the monostable multivibrator, this circuit does not require any external trigger to change the

state of the output, hence the name free-running. Before going to make the circuit, make sure your 555 IC is

working. For that go through the article: How to test a 555 IC for working An astable multivibrator can be

produced by adding resistors and a capacitor to the basic timer IC, as illustrated in figure. The timing during

which the output is either high or low is determined by the externally connected two resistors and a

capacitor. The details of the astable multivibrator circuit are given below.

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Ultrasonic switchPin diagram discription

Figure:-Pin Diagram

Pin 1 is grounded; pins 4 and 8 are shorted and then tied to supply +Vcc, output (VOUT is taken form pin 3;

pin 2 and 6 are shorted and the connected to ground through capacitor C, pin 7 is connected to supply + VCC

through a resistor RA; and between pin 6 and 7 a resistor RB is connected. At pin 5 either a bypass capacitor

of 0.01  F is connected or modulation input is applied.

Astable Multivibrator Operation

Standard 555 Astable Circuit

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Ultrasonic switchIn astable mode, the 555 timer puts out a continuous stream of rectangular pulses having a specified

frequency. Resistor R1 is connected between VCC and the discharge pin (pin 7) and another resistor (R2) is

connected between the discharge pin (pin 7), and the trigger (pin 2) and threshold (pin 6) pins that share a

common node. Hence the capacitor is charged through R1 and R2, and discharged only through R2, since pin

7 has low impedance to ground during output low intervals of the cycle, therefore discharging the capacitor.

In the astable mode, the frequency of the pulse stream depends on the values of R1, R2 and C:

2.1.5 IC CA 3140

CA3140 has gate protected MOSFETs (PMOS) transistors in the input circuit to provide very high input

impedance typically around 1.5T Ohms. The IC requires very low input current as low as 10pA to change

the output status, high or low. The IC has very fast response and high speed of performance. The output

stage of the IC uses bipolar transistors and includes built in protection against damage from load terminal

short circuiting to either supply rails or to ground.

The use of PMOS FET in the input stage results in common mode input voltage capabilities down to 0.5

volts below the negative supply terminals. These operational amplifiers are internally phase compensated to

achieve stable operation in unity gain follower operation, and additionally, have access terminal for a

supplementary external capacitor if additional frequency roll-off is desired. Terminals are also provided for

use in applications requiring input offset voltage Nulling.

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Ultrasonic switchPin connections

The CA3140 Series has the same 8-lead pin out

Figure:-Pin Diagram of CA3140

Pin1Offset Null

Pin2 Inverting input INV

Pin3 Non inverting input Non-INV

Pin4 Ground- Negative supply

Pin5 Offset Null

Pin6 Output

Pin7 Positive supply

Pin8 Strobe

Operating Conditions

Supply voltage 36 volt maximum

Input terminal current 1mA

2.1.6 Transistor

A transistor is a semiconductor device used to amplify and switch electronic signals. It is made of a solid

piece of semiconductor material, with at least three terminals for connection to an external circuit. A voltage

or current applied to one pair of the transistor's terminals changes the current flowing through another pair of

terminals. Because the controlled (output) power can be much more than the controlling (input) power, the

transistor provides amplification of a signal. Today, some transistors are packaged individually, but many

more are found embedded in integrated circuits

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Ultrasonic switchThe essential usefulness of a transistor comes from its ability to use a small signal applied between one pair

of its terminals to control a much larger signal at another pair of terminals. This property is called gain. A

transistor can control its output in proportion to the input signal; that is, it can act as an amplifier.

Alternatively, the transistor can be used to turn current on or off in a circuit as an electrically controlled

switch, where the amount of current is determined by other circuit elements.

SL00

S stands for slew and L stands for low frequency... and 100 is the gain of the transistor

SK100

BC548 Transistor

BC548 is general purpose silicon, NPN, bipolar junction transistor. It is used for amplification and switching

purposes. The current gain may vary between 110 and 800. The maximum DC current gain is 800.Its

equivalent transistors are 2N3904 and 2SC1815. These equivalent transistors however have different lead

assignments. The variants of BC548 are 548A, 548B and 548C which vary in range of current gain and other

characteristics.The transistor terminals require a fixed DC voltage to operate in the desired region of its

characteristic curves. This is known as the biasing. For amplification applications, the transistor is biased

such that it is partly on for all input conditions. The input signal at base is amplified and taken at the emitter.

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Ultrasonic switchBC548 is used in common emitter configuration for amplifiers. The voltage divider is the commonly used

biasing mode. For switching applications, transistor is biased so that it remains fully on if there is a signal at

its base. In the absence of base signal, it gets completely off.

 

2.1.7 Diode 1N4148

The 1N4148 is a standard silicon switching diode. Its name follows the JEDEC nomenclature. The 1N4148

has a DO-35 glass package and is very useful at high frequencies with a reverse recovery time of no more

than 4ns.

2.1.8 Relay

A relay is an electrically operated switch. Many relays use an electromagnet to operate a switching

mechanism mechanically, but other operating principles are also used. Relays are used where it is necessary

to control a circuit by a low-power signal (with complete electrical isolation between control and controlled

circuits), or where several circuits must be controlled by one signal. The first relays were used in long

distance telegraph circuits, repeating the signal coming in from one circuit and re-transmitting it to another.

Relays were used extensively in telephone exchanges and early computers to perform logical operations.

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Ultrasonic switch

We have used 6v,200 relay in this ultrasonic switch.

2.2 Software details/description

Diptrace

DipTrace is an advanced PCB design software application that consists of 4 modules: PCB Layout with

high-class shape-based auto-router, Schematic Capture, Component and Pattern Editors that allow you to

design your own component libraries. Besides being very simple to learn, this software has a very

intuitive user interface and many innovative features. For instance, a schematic can be converted to a

PCB with one mouse click.

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Ultrasonic switchChapter-3

Details of Technology

3.1 Ultrasonic Technology

This technology can be used for measuring: wind speed and direction (anemometer), fullness of a tank and

speed through air or water. For measuring speed or direction a device uses multiple detectors and

calculatesthe speed from the relative distances to particulates in the air or water. To measure the amount of

liquid in a tank, the sensor measures the distance to the surface of the fluid. Systems typically use a

transducer which generates sound waves in the ultrasonic range, above 18,000 hertz, by turning electrical

energy into sound, then upon receiving the echo turn the sound waves into electrical energy which can be

measured and displayed.The technology is limited by the shapes of surfaces and the density or consistency

of the material. For example foam on the surface of a fluid in a tank could distort a reading.

Ultrasound

Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing.

Although this limit varies from person to person, it is approximately 20 kilohertz (20,000 hertz) in healthy,

young adults and thus, 20 kHz serves as a useful lower limit in describing ultrasound. The production of

ultrasound is used in many different fields typically to penetrate a medium and measure the reflection

signature or supply focused energy. The reflection signature can reveal details about the inner structure of

the medium, a property also used by animals such as bats for hunting. The most well known application of

ultrasound is its use in sonography to produce pictures of fetuses in the human womb. There are a vast

number of other applications as well.

3.2 Wireless Technology:-

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Ultrasonic switch In telecommunications, wireless communication may be used to transfer information over short distances (a

few meters as in television remote control) or long distances (thousands or millions of kilometers for radio

communications). The term is often shortened to "wireless". It encompasses various types of fixed, mobile,

and portable two-way radios, cellular telephones, personal digital assistants (PDAs), and wireless

networking. Other examples of wireless technology include GPS units, garage door openers and or garage

doors, wireless computer mice, keyboards and headsets, satellite television and cordless telephones.

Wireless operations permits services, such as long range communications, that are impossible or impractical

to implement with the use of wires. The term is commonly used in the telecommunications industry to refer

to telecommunications systems (e.g. radio transmitters and receivers, remote controls, computer networks,

network terminals, etc.) which use some form of energy (e.g. radio frequency (RF), infrared light, laser light,

visible light, acoustic energy, etc.) to transfer information without the use of wires. Information is

transferred in this manner over both short and long distances.

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Ultrasonic switchChapter-4

Problem Formulation and Methodology

4.1. Problem Formulation:-

To set the ultrasonic sensor.

There is a big problem of sensing the ultrasonic signal from transmitter to receiver

In the Ultrasonic switch problem is occurred that the wired circuitry that make circuit bulky

and something less compatible

Solutions:-

In ultrasonic switch to sense the signal we put the receiver infront of the transmitter.

For the proper connection soldering of the components done individually.

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Ultrasonic switch4.2 Block diagram with detail

Figure:-Block Diagram of Ultrasonic Switch

Fig. 1 shows the block diagram of the ultrasonic switch. The transmitter uses a 555 based astable

multivibrator. It oscillates at a frequency of 40-50 KHz. An ultrasonic transmitter transducer is used here to

transmit ultrasonic sound effectively. The transmitter runs on a 9V battery. The ultrasonic receiver circuit

uses an ultrasonic receiver transducer to sense ultrasonic signals. It uses a two-stage amplifier, a rectifier

stage, and an operational amplifier in inverting mode. Output of operational amplifier is connected to a relay

through a complimentary relay driver stage. A 9V adapter can be used to power receiver circuit. When

switch S1 of transmitter is pressed, it generates ultrasonic sound. Ultrasonic receiver transducer receives the

sound and converts it to electrical variations of the same frequency. Transistors Q3 and Q4 amplify these

signals. The amplified signals are then rectified and filtered. The filtered DC voltage is given to inverting

pin of operational amplifier IC2. The non-inverting pin of IC2 is connected to a variable DC voltage through

VR2 which determines the threshold value of ultrasonic signal received by the receiver for operation of relay

RL1. The inverted output of IC2 is used to bias transistor Q5. When transistor Q5 conducts, it supplies base

bias to transistor Q6. When transistor Q6 conducts, it energises the relay RL1. The relay can be used to

control any electrical or electronic equipment. Frequency of ultrasonic sound gener-ated can be varied by

adjusting VR1. Adjust it for maximum performance. Ultrasonic sounds are highly directional. So when you

are operating the switch the ultrasonic transmitter transducer of transmitter should be placed towards

ultrasonic receiver transducer of receiver circuit for proper functioning. The receiver is always kept in

switched on position.

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Ultrasonic switch 4.3 Circuit diagram with details

Working

When switch S1 of transmitter is pressed, it generates ultrasonic sound. The sound is received by ultrasonic

receiver transducer. It converts it to electrical variations of the same frequency. These signals are amplified

by transistors T3 and T4. The amplified signals are then rectified and filtered. The filtered DC voltage is

given to inverting pin of op-amp IC2. The non- inverting pin of IC2 is connected to a variable DC voltage

via preset VR2 which determines the threshold value of ultrasonic signal received by receiver for operation

of relay RL1. The inverted output of IC2 is used to bias transistor T5. When transistor T5 conducts, it

supplies base bias to transistor T6. When transistor T6 conducts, it actuates the relay. The relay can be used

to control any electrical or electronic equipment. Important hints:

1. Frequency of ultrasonic sound generated can be varied from 40 to 50 kHz range by adjusting VR1. Adjust

it for maximum performance.

2. Ultrasonic sounds are highly directional. So when you are operating the switch the ultrasonic transmitter

transducer of transmitter should be placed towards ultrasonic receiver transducer of receiver circuit for

proper functioning.

3. Use a 9-volt PP3 battery for transmitter. The receiver can be powered from a battery eliminator and is

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Ultrasonic switchalways kept in switched on position.

4. For latch facility use a DPDT relay if you want to switch on and switch off the load. A flip-flop can be

inserted between IC2 and relay. If you want only an ON-time delay use a 555 only at output of IC2. � �

The relay will be energised for the required period determined by the timing components of 555 monostable

multivibrator.

5. Ultrasonic waves are emitted by many natural sources. Therefore, sometimes, the circuit might get falsely

triggered, espically when a flip-flop is used with the circuit, and there is no remedy for that.

4.4 Flow chart process

Ultrasonic Transmitter is  based on a 4011 quad 2-input NAND gate. Two of the gates, IC1a and IC1b, are

used as a conventional CMOS Astable circuit whose oscillation frequency is set by capacitor C1, resistors

R6 and R7, plus preset VR2, which adjusts the frequency. Gates IC1c and IC1d buffer the outputs from

IC1a and IC1b and drive the ultrasonic transmitter transducer, X1, in push-pull mode.

 In   the    Receiver circuit,  ultrasonic echo signal is received by transducer X2. It is first amplified by the

2-stage amplifier based on transistors TR1 and TR2. The output from TR2 is rectified by diode D1 and

smoothed by capacitor C4. The result is a voltage level at inverting terminal of IC2 which varies between

1·4V and 2·7V when X2 is not receiving ultrasound echoes, but falls to 1·2V when a strong enough echo

from an object is detected. The rectified signal goes to op amp comparator IC2's inverting input, pin 2.

The signal is compared with a reference voltage set by preset VR3, and applied to IC2's non-inverting

input, pin 3. The output at IC2 pin 6 is low when there is no echo, but swings high when an obstacle ahead

of the system is detected.

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Ultrasonic switch4.5 Component list

Transmitter Parts:

IC1 NE555 timer IC

VR1 10k variable resistor

R1 4.7k resistor

R2 18k potentiometer

R3 1k resistor

R4, R5 220 ohm resistor

C1 680 picofarad capacitor

C2 0.01uf capacitor

D1, D2 1N4148 Diode

T1 SL100 NPN transistor

T2 SK100 PNP transistor

S1 SPST momentary contact switch

XMTR Ultrasonic transmitter 40-50khz

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Ultrasonic switchReceiver Parts

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RCVRUltrasonic Receiver 40-50khz

RL1 6volt 200ohm resistor

IC2 CA3140

VR2 250k Variable Resistor

R6 390k Resistor

R7 470k Resistor

R8, R12 15k Resistor

R9 12k

R10, R13 10k

R11 4.7k

R14 100k Resistor

R15 33 ohm Resistor

C30.22uf ceramic capacitor

C4 0.1uf ceramic capacitor

C5 560n ceramic capacitor

T3,T4 BC548 NPN Transistor

T5 BC558 PNP Transistor

T6 SL100 NPN Transistor

D3,D4,D5 1N4148 Diode

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Ultrasonic switchChapter-5

Simulation & Results

Step-I :- In the step first the power supply of 9volts giving the supply to the circuitry.

The 9volts power supply is initially fed on the IC-555.

Step-II:- In the step second frequency of ultrasonic sound generated can be varied from 40 to 50 kHz

range by adjusting VR1. Adjust it for maximum performance.

Step-III:- In the step third the ultrasonic transmitter transducer of transmitter should be placed towards

ultrasonic receiver transducer of receiver circuit for proper functioning.

Step-IV:- For latch facility use a DPDT relay if you want to switch on and switch off the load. A flip-flop

can be inserted between IC2 and relay. If you want only an ON-time delay use a 555 only at output of � �

IC2. The relay will be energised for the required period determined by the timing components of 555

monostable multivibrator.

Finally the relay can operated by varying the potentiometer and putting the receiver infront of the

transmitter.

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Ultrasonic switch5.1 Layout

Figure:Layout of Transmitter

Figure: Layout of Receiver

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Ultrasonic switch

5.2 Project Flow

Figure:- Project Flow

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Ultrasonic switch

5.3 Actual Hardware Diagram

Figure: Hardware diagram of Ultrasonic switch

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Ultrasonic switchChapter-6

Applications,Limitations & Advantages

6.1 Applications

An ultrasonic switch is a sensor that uses sound waves to detect an object. This is done through a technique

using high frequency sound waves as the sensing medium. It can be used in either through beam or

proximity configurations.The general purpose ultrasonic switch and controller provides non-contect level

detection up to 24.6’(7.5m) with 3 SPDT 60 VA 1A relays. EchoSwitch 2 features an LCD display with

digital push button configuration. Each relay can be configured on a single set point alarm or latched on two

set points for automatic fill or empty in simplex, duplex or triplex control modes with integral timer delay.

The switch is well suited for a broad range of corrosive,waste and slurry type media.EchoSwitch 2 is

broadly selected for atmosphere day tank,pump lift station and sump applications.

It is used to control many electrical and electronics components.

The output of relay is used in door automation.

6.2 Limitations

One of the drawbacks to ultrasonic sensors is that there's no way to tell the difference between small objects

and large objects because the pulse that's emitted is cone shaped. Because of the shape, an echo will be

returned by all objects the pulse comes into contact with. A simple fix to this problem is to use rotating

sensors or multiple sensors.

6.3 Advantages

When used for sensing functions, the ultrasonic method has unique advantages over conventional

sensors:

Discrete distances to moving objects can be detected and measured.

Less affected by target materials and surfaces, and not affected by color. Solid-state units have

virtually unlimited, maintenance free life. Can detect small objects over long operating distances.

Resistance to external disturbances such as vibration, infrared radiation, ambient noise, and EMI

radiation.

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Ultrasonic switchFuture Scope & Conclusion

7.1 Future ScopeCompared to inductive position sensors or photoelectric sensors, ultrasonic sensors are used less often.

However, there are quite a few applications where the use of ultrasound technology has great benefits. In

addition to insensitivity to contamination, the decisive advantage is the principle of sonic time-of-flight

measurement used in almost all ultrasonic sensors. Even binary sensors are based on a time-of-flight

measurement, so a precise switching point and reliable distinction of several targets in the measurement field

present no problem. Furthermore, ultrasound technology provides a long sensing range with a comparatively

small sensor.

A great advantage of ultrasonic sensors is distance measurement. Ultrasonic sensors are particularly well-

suited for filling height measurement. There are a large number of cylindrical and rectangular designs that

are suitable for various installation conditions.

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Ultrasonic switch 7.2 Conclusion

The battery powered ultrasonic level sensor, a non-contact type sensor, is suitable for corrosion prone,

hazardous, and maintenance free applications. The devices available in the market all work on the same

basic principle of the generation and receiving of acoustic waves, but are different in their designs to fit

within specific industrial applications. When selecting an ultrasonic level detector, one needs to check

the possible application, working voltage, and operating range.

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Ultrasonic switch

References

http://en.wikipedia.org/wiki/Ultrasonicswitch

Ultrasonics Basics (Banner Engineering)

http://ultrasonicswitch.com/ultrasonicsensor.june 2010

Wireless Technologies.ultrasonic sensors.April 15 2008

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