Electromechanical Transducer : Working, Types & Its Applications

A transducer is an electronic device used to change energy from one form to other. Generally, a transducer changes one form of energy signal to another form of energy signal. Examples of a transducer are; microphones, solar cells, incandescent light bulbs, electric motors, etc. These devices are frequently used where electrical signals are changed to other physical quantities like force, energy, light, torque, position, motion, etc. There are different types of transducers like current, pressure, magnetic field, thermocouple, piezoelectric, strain gauge, mutual induction, and electromechanical transducer. This article discusses an overview of an electromechanical transducer – working with applications.

What is Electromechanical Transducer?

An electromechanical transducer is a type of device used to convert either an electrical signal into sound waves like in a loudspeaker (or) converts a sound wave into an electrical signal like in a microphone. In other words, the device which converts mechanical motion into electric signals is known electromechanical transducer. The electromechanical transducer examples are; a loudspeaker, a piezoelectric transducer, a microphone & permanent-magnet instrument’s measuring mechanism.

Electromechanical Transducer Working Principle

An electromechanical transducer simply works by changing mechanical motion into variations of a current or voltage & vice versa. These transducers are mainly used as activating mechanisms within automatic control systems & also as sensors of mechanical motion within measurement & automation technology. The classification of these transducers can be done based on the conversion principle utilized as electromagnetic, resistive, magnetoelectric, electrostatic types and also the type of o/p signal like analog & digital types.

These types of transducers are estimated with respect to their static & dynamic characteristics, the sensitivity E = Δy/Δx, the static signal error, the o/p signal’s operating frequency range & the static conversion error.

Electromechanical Transducer Diagram

The electromechanical transducer which is used to implement the Capnography technique is shown below. The study of carbon dioxide expiration is called capnometry. The electromechanical transducer in the following diagram has an IR light source that produces broad-spectrum radiation in the 2 to 16 µm range. IR radiation sources that are utilized in capnography should have uniform emissivity, high irradiance, spectral uniformity & large radiant area. From real sources, the radiation is always low as compared to an ideal blackbody, which has the highest emissivity.

The quartz tungsten halogen lamps hot filament simply provides strong near IR output. In the above diagram, the broadband infrared light ray passes through an IR filter then it transmits light in the maximum absorption wavelength of the CO2 like 4.26 µm with 0.07 μm of bandwidth. At low frequencies, the light ray is sampled through a rotating chopper wheel. Once this wheel turns, then their re is a position wherever infrared light transmits throughout the sample chamber & the radiation is absorbed through available CO2 molecules within the exhaled air.

In a second position, infrared light transmits throughout the sample & the reference chambers. Here, the Reference chamber is sealed with CO2. In the remaining location, no light crosses the rotary wheel. The radiation that transmits throughout the wheel was not absorbed through CO2 molecules and is simply gathered by the photodetector, generally a GeAs photodiode.

The pulsed photodiode o/p current frequency is equivalent to the sampling &its amplitude is adjusted through the quantity of transmitted radiation. The oscillating signal intensity is processed to decide the concentration of the CO2 in the patient’s breath. So by using the capnography technique in real-time, the ventilation status of patients and also potential breathing complications can be monitored by Health care providers.

Electromechanical Transducer Types

There are different types of electromechanical transducers which are discussed below.

Linear Variable Differential Transformer

LVDT is an electromechanical transducer, used to change the object’s rectilinear motion to which it is connected mechanically into a variable voltage, current or electrical signal. Please refer to this link to know more about LVDT.

Please refer to this link to know more about LVDT.

Elastomeric Transducers

The elastomeric transducer is an electromechanical transducer used to change electrical energy into mechanical energy. The polymeric structures optimizing these transducers mainly depend on the properties of dielectric. The optimized members consist of silicone Q, polydimethylsiloxane PDMS & semicrystalline polyurethane PUR. So, semicrystalline polyurethane is mainly preferred due to its dielectric constant range from 3 to 10 & high ionic conductivity, particularly at elevated temperatures. Polydimethylsiloxane dielectric constant range is comparatively low ranging from 2.5 to 3 and Silicone Q is similar to semicrystalline polyurethane although it has a low glass transition temperature.

Piezoelectric Nanogenerator

The piezoelectric nanogenerator is one type of electromechanical transducer used to change the energy from mechanical to electrical using piezoelectric ZnO nanowires which can be activated through small physical motions & work in a huge range of frequencies. These are used in innovative healthcare applications because of their simple implementation, self-powering nature, and highly efficient energy conversion like electrical stimulation therapy, in the space of active detecting & human biomechanical energy harvesting to intermediary power above body devices.

Dielectric Elastomers

Dielectric elastomer (DEs) is an electromechanical transducer, used to change electrical energy into mechanical energy. These elastomers work in two modes like actuator and general. In actuator mode, it changes the energy from electrical to mechanical whereas, in general mode, it converts the energy from mechanical to electrical. These are smart material systems that generate large strains. These belong to the electroactive polymers group. These have a high elastic energy density & are lightweight.

Advantages and Disadvantages

The advantages of electromechanical transducers are discussed below.

• This transducer output can be used easily by transmitting & processing for measurement purposes.
• The electrical systems are controlled with an extremely small range of power.
• These transducers will reduce the friction effects as well as other mechanical non-linearities.
• Because of the integrated circuit technology, many systems are compact, portable & less weight.
• There is no chance of mechanical failures.
• Mass inertia problems can be reduced.
• No mechanical wear & tear.

The disadvantages of electromechanical transducers are discussed below.

• This transducer is expensive.
• While circuit designing, the aging effects & active components drift of parameters should be considered. So, this will make the design complex.

Applications

The applications of an Electromechanical Transducer are discussed below.

• The electromechanical transducer is used to change an electrical signal into sound waves or sound waves into an electrical signal.
• This transducer changes physical motion into an o/p voltage, the amplitude & phase where these are proportional to position.
• This transducer receives waves from an electric system & transmits them to a mechanical system.
• These are used for measuring vibration.
• This is used to provide the linear output that is proportional to the input of angular displacement.
• An electromechanical transducer like RVDT is mainly used for measuring angular displacement.
• This device changes the signal from electrical to mechanical or physical o/p through moving parts.
• This type of transducer is mainly designed for replacing the torque motor within the fixed nozzle flapper servo tap.
• RVDT electromechanical transducer converts an object’s rectilinear motion to which it is mechanically connected into an equivalent electrical signal.

What is the difference between an electromechanical transducer and an electrochemical transducer?

The electromechanical transducer is a device that either changes an electrical signal into sound waves otherwise changes a sound wave into an electrical signal. The electrochemical transducer is used to report changes in the form of an electrical signal which is proportional directly to the analyte concentration.

How do you select the right electromechanical transducer for a particular application?

There are many parameters that need to consider while selecting an electromechanical transducer like operating range, accuracy, operating principle, sensitivity, loading effect, environment compatibility, etc.

Can electromechanical transducers be used in hazardous environments?

When an electromechanical transducer is electrically connected to any equipment in a hazardous environment then an electrical safety barrier should be used within series by the connection.

How do you calibrate an electromechanical transducer?

The mechanical transducer must be calibrated throughout its period of service because the sensitivity of this transducer changes based on the usage & the stresses applied over the materials of which they are made. So, a reciprocity method is used to calibrate an electromechanical transducer which provides a description of the principle of the technique & after that its applications while calibrating an electromechanical transducer.

What are some common troubleshooting tips for electromechanical transducers?

• The troubleshooting is used to check whether a transducer is working or not with a voltmeter. Connect this transducer to the voltmeter & excite the transducer through the proper excitation voltage. After that measure the output voltage of the transducer at no load.
• Make sure whether load and pressure are constant or not.
• Verify excitation power supply stability.
• Check millivolt o/p through the voltmeter.
• Ensure for RFI or EMI interference.

Thus, this is an overview of electromechanical transducer – working principle, types, advantages, disadvantages & applications. A transducer that receives waves from an electric system & transmits them to a mechanical system is also known as an electromagnetic transducer. Here is a question for you, what is a transducer?