A transducer is a device that is used to detect a signal or energy and convert it from its original form to the desired form. The process of detecting the presence or change in the signal in the surroundings is called sensing, while the process of converting the detected energy from one form to another is called transduction. Physical quantities such as pressure, temperature, the flow of fluids, sound waves, etc. can be easily detected and converted from one form to another with the help of transducers. The task of directly measuring the magnitude and other related properties of the signal values present in the surroundings is quite difficult as the physical attributes of the signal cannot be directly recorded. To overcome this demerit, transducers are employed that help converts the physical signal into an electrical format and enable easy measurement of the physical attributes of the signal. Some prime advantages of using transducers in signal measurement include ease of amplification or attenuation of the signal, wide operation range, low input power requirements, compact size, etc. While selecting the type of transducer, the user must observe if the device’s working principle matches the application’s needs. Also, factors such as sensitivity, operating range, accuracy, error factor, loading effect, noise cancellation capability, static characteristics, stability, and reliability must be considered before selecting a transducer for a particular application.
Uses of Transducers in Real Life
Transducers are used for a variety of applications in our daily life. Some of the prominent examples of real-life applications of transducers are given below:
1. Medical Diagnostic Equipment
A variety of medical diagnostic tasks such as obtaining the images of a foetus periodically to observe its growth, viewing the internal condition of the uterus, ovaries, and abdomen, monitoring the working of the heart, etc. make use of transducers. Also, transducers play a significant role in urology, orthopaedics, obstetrics, and ophthalmology. Transducers that are used for medical diagnosis typically tend to convert the physiological signals obtained from the body into electrical signals. The electrical signals then can be coupled to the output devices for observation and analysis purposes. The data recorded by such transducers can be recorded and displayed in the form of video signals, images, or graphs. Ultrasound sensors, 1D array transducers, 2D array transducers, and mechanical wobble transducers are some of the most prominently used transducers in medical applications.
Most manufacturing processes in automotive and aerospace engineering applications use internal combustion engines to drive the vehicles. Before deploying automotive and aerospace vehicles in real life, they are subjected to multiple performance test procedures, calibration examinations, and quality checks. For such purposes, numerous transducers such as pressure sensors, flow sensors, and Mensor transducers are used. To conduct such tests, the engine is required to be operated in an engine test cell. An engine test cell can be defined as a controlled environment where the system under observation is attached to load and the resultant characteristics are distinctly measured and recorded. Generally, an engine test cell includes a dynamometer, cooling system, ventilation system, exhaust system, fuel system, transducers, sensors, actuators, and various other related parts. The data gathered by the transducers attached to the engine test cells include barometric pressure, compressor inlet pressure, compressor discharge pressure, turbine inlet pressure, turbine discharge pressure, manifold absolute pressure, and exhaust black pressure values. The data is obtained in digital as well as analogue format and can be converted into any desired format. Further, the data is then interlinked to the data acquisition and processing units for analysis purposes.
3. Electric Cigarette Lighters
Electric cigarette lighters are a classic example of the daily use items that employ transducers for their prime operation. An electric cigarette lighter mainly contains a piezoelectric transducer in its internal circuitry that controls the generation or termination of the spark upon button press. When the user presses the button of the lighter, a spring-loaded hammer tends to strike the piezoelectric crystal placed in the lighter circuitry. This results in the generation of a voltage difference across the spark gap and ignites the gas.
4. Strain Gauges
Strain gauges are usually employed in applications where the user needs to measure the value of the mass of an object or compare mass related properties with a reference object or any other unknown quantity. Such devices typically make use of diaphragm transducers to detect changes in the electrical resistance of the device in response to the applied mechanical pressure. The advantages of using diaphragm transducers in strain gauges include high efficiency, sensitivity, and precision value.
Transducers are the devices that tend to form a stable base for the operation of almost all sound devices such as loudspeakers, microphones, repeaters, etc. Mostly, loudspeakers and headphone devices make use of sound transducers to detect the input electrical signals and generate corresponding sound signals. This is generally done by converting the input electrical signal into mechanical pressure. Further, mechanical pressure can be used to induce vibrations in the speaker membrane. The constant frequency vibrations caused in the speaker membrane ultimately get reflected as the output of devices or sound signals. Also, other types of transducers such as electrostatic transducers, electrodynamic transducers, balanced armature transducers, electromagnetic transducers, magnetostatic transducers, etc. can also be used in speakers to produce sound waves from a recorded or live electrical signal.
An antenna can be defined as a transducer device that can be used to convert a radio-frequency signal into an alternating current signal and vice versa. Based on the type of signal transmitted and received, antennas can be divided into two types, namely receiving antenna and transmitting antenna. The receiving antenna tends to take radiofrequency signal as input and outputs alternating current, while the transmitter antenna obtains electrical signal as input and radiates output in the form of radiofrequency. Receiver and transmitter antennas in conjunction can be used for long-distance as well as short-distance communications. Also, satellite communication, video transmission via dish antennas, and data transmission through microwave antennas tend to form some of the basic examples of applications in real life that make use of antennas as transducers.
7. Research Equipment
Since different types of transducers available in the market can be used to convert one form of energy into other formats, they can be used for multiple research and development purposes. Scientists and researchers employ transducers to convert the input signal into the desired format to perform experiments and/or to verify the existence of pre-existing laws and phenomena. The ability of transducers to convert the input signal into any desired format makes them best suited for all types of analysis procedures. Also, transducers can use a wide range of physical quantities such as pressure, stress, strain, flow, tension, force, mass, etc. as the input signal and can output the processed signal in the user’s desired format. Other advantages of using transducers for research, development, and analysis applications include remote operability, minimized friction and mass inactivity effects.
8. Measuring Distance
One of the prime applications of a transducer includes measuring the distance between two objects or estimating the distance of a target object from a particular point. For this purpose, ultrasonic transducers are generally employed that make use of the property of sound waves by virtue of which they get bounced back and travel in reverse direction upon striking an obstacle or any rigid surface. The electronic systems or circuits used for the task of distance estimation generally contain an ultrasonic transducer module embedded with the other circuit elements and components that handle the transmission and reception of signals as well as conversion of the processed input signal into the user’s desired format. Using transducers for distance measurement purposes is advantageous as they can be easily used in places that are hard to reach and are susceptible to causing health hazards. Also, the reliability of measuring devices that are equipped with ultrasonic transducers is significantly higher than the traditional measuring devices or gadgets.
9. Air conditioning Heating and Ventilation Devices
Air conditioning, heating, and ventilation devices primarily make use of temperature transducers to control and execute the device’s operations. The main objective of the temperature transducer embedded in the internal circuitry of such systems is to continuously keep monitoring the temperature of the air in the surroundings and communicate the observed data or variation in the temperature to the processing units of the device. The processors further analyse the difference between the user’s desired temperature and humidity characteristics and the current physical characteristics of the surroundings and execute the necessary operation to restore and maintain the ambient conditions. The transducers used in such applications are generally present in the internal circuitry of the device in the form of integrated circuits or chips. The input of the temperature transducers used in the heating, ventilation and air conditioning devices is generally an analogue signal, while the output is generated in the form of an electrical signal. The electrical signal is usually preferred as it is easier for analysis and observatory purposes.
10. Electronic Drum Pads
Electronic drum pads tend to form yet another example of the real-life applications that make use of transducers. Electronic drum pads are an electronic musical instrument that is usually considered an upgraded or advanced version of the acoustic drum kit. The working of electronic drum pads typically relies on a sound module or drum module and transducers. The sound module or drum module tends to act as the brain of the system that processes all kinds of available sound signals and generates a corresponding output. The sound module of electronic drum pads typically includes different sound effects from a variety of musical genres such as jazz, rock, hip-hop, brush, etc. and other features such as record beats, pre-recorded music lectures, play-along tracks, etc. The transducers used in electronic drum pads are basically embedded in the drum triggers or trigger pads. The main objective of the transducers used by the electronic drum pads is to sense the vibrations introduced by the music system and transform the input into an amplified electrical signal.
11. Load Estimation of an Engine
Transducers can also be utilized in various automobile applications such as to estimate the load of the engine. This can be done by using the transducers as MAP or manifold absolute pressure sensors in fuel injection systems to estimate the diverse absolute pressure value and maintain or ensure the correct combination of acceleration, emissions, fuel economy, and engine smoothness.
12. Knock of the Engine
Engine knock is caused when uneven combustion of the compressed air-fuel mixture takes place in the internal combustion engine of the vehicle. The premature combustion of the fuel mixture generally takes place due to high temperature and pressure. The knocking of the engine causes the vehicle to make sharp frequency sounds. A variety of pressure and temperature transducers are employed by automotive engineers and mechanics to observe and notice the knock of the engine.
13. Leak Testing
A variety of leak testing methods such as the differential pressure decay method make use of pressure transducers for their prime operation. The differential pressure testing method typically involves pressurizing the reference volume with a test part and measuring the pressure difference between the test item part and the non-leaking reference volume with the help of transducers.
14. Speed Breakers
Some speed breakers installed on the highways are embedded with pressure transducers that tend to take the pressure exerted by the vehicles as input and produce an electrical signal as output. The electrical energy produced as a result may be used to power various gadgets and electrical equipment such as light bulbs, fans, charging devices, etc.
A thermocouple or thermoelectric thermometer is a device that is generally used to measure the temperature of a surface or the surroundings. A thermocouple typically consists of two metallic wires that are connected to a measuring device. Thermocouples are basically passive transducers that tend to detect the magnitude of the temperature of an object or the heat energy present in the surroundings and convert the input into electrical form. The electrical form of the signal enables quick analysis and easy processing of data.
16. Pressure Level Indicators using Bourdon Tube
A bourdon’s tube is a mechanical device that is generally used to monitor pressure exerted by different types of fluids. Bourdon’s tube is yet another example of an application that demonstrates the process of transduction in real life. Bourdon’s tube typically contains components such as inlet pipe, socket block, stationary end of Bourdon tube, moving end of Bourdon tube, pivot and pivot pin, sector gear, indicator needle, and other parts. It obtains external pressure as input and produces its electrical equivalent as output. The instrument was invented in 1849 and is named after its inventor Eugene Bourdon who was a French engineer. The main advantage of using Bourdon’s tube for pressure measurement is that it does not require electrical power for its operation. Also, Bourdon tubes are relatively inexpensive, more compact, safe, accurate, and precise. Bourdon’s tube typically falls under the category of primary transducers as it is generally employed in combination with another type of transducer in most applications to detect the physical change of quantities and convert the input signal into an electric or physical format. Most pressure level indicating devices make use of Bourdon’s tube. Also, other real-life applications such as pressure monitoring systems employed in steam boilers, hot bathrooms, compressors, or to measure the pressure value of air in vehicles tube tires also make use of such transducers.