Transducer | Electrical transducers

The measurement of non-volatile quantities requires that a sensor device be used that transforms the magnitude of the physical quantities into electrical quantities. The device that converts energy from one form to another is called a transducer or electrically. They say,

The reason for converting a physical sign into an electrical signal is that the electrical signal can be easily transmitted or adapted and used for measurement. In modern times, the use of transducers has become necessary due to digital computers. This makes operation easier. The transducer present in the electron mechanization system detects or senses the quantities and amounts to be measured. Transducers provide proportional electrical output signals.

With the help of a transducer, unaccounted amounts are measured. Electrical measurement is easier than other measurement methods. Electrical measurements are more commonly used in telemetry. Heat, pressure, velocity of sound, heartbeat, blood pressure etc. or other physical activities are examples of unaccounted amounts. The specific amount measured with the help of a transducer is obtained as a useful output.

The transducer is broadly the instrument that transfers energy by pairing it in such a way that the units undergo a desirable change, but in general the transducer converts the information or signals into another form.

Almost all types of transducers are affected by temperature. All transducer manufacturers specify the temperature range within which the transducer can function correctly. Although the transducer is not completely destroyed by using it at temperature-forward and reverse temperatures, its performance is reduced. There are many practical considerations that need to be taken into consideration when choosing a transducer in addition to its functionality.
Such as humidity of the atmosphere, power expenditure, size, weight, other sub-resources etc.

Loudspeaker is an example of an electrical transducer that converts an electrical signal into a pressure wave (sound)

Types of Error in transducers

Inverse Transducer- Inverse transducer is a device. Which converts electrical quantity into non-electrical quantity. It is a precision actuator with electrical input and low power non-electrical output. A piezoelectric crystal acts as an inverse transducer, because its dimension changes due to mechanical displacement when its surface across voltage is applied.

Example - Moving current carrying in the magnetic field also behaves like an inverse transducer, as the carrying current is converted into force due to rotational displacement. Many data indicator and recording devices are also an inverse Transducer

Classification - Transducers are classified into the following classes

(i) Bassed on application - Depending on the applications, the transducers are of the following two types -

Primary Transducer- The transducer used in the first stage of measurement is called a primary transducer. It first measures the measurement signal. After sensing the primary transducer input signal directly converts it into electrical form. Thermistors and thermocouples fall under the category of primary transducers.
Secondary Transducer- The input signal in the secondary transducer is sensed by the detector. The output of this transducer is lower than the input signal. This transducer displays the input signal electrically. LVDT Is the prime example of a secondary transducer.

(ii) Based on Energy Conversion - With the help of a transducer, the signals are converted from one form to another, meaning there is also a change of energy. Depending on the energy conversion, there are two types of transducers -

Active Transducer - Active transducers are of the self-generating type. These transducers generate the voltage and current themselves. They convert the input signal into its corresponding electrical current or voltage without using any external power source. This type of transducer receives energy from the input signal itself to work. The output from the active transducer is very poor. Hence amplifiers are used with active transducers. Examples - thermo-electromagnetic pairs, piezoelectric pick-ups, light conductive cells etc.
Passive Transducer - Transducers that perform an electrical parameter, such as resistance. The inductance or capacitance changes according to the input signal is called passive transducer. This type of transducer requires external energy source for energy conversion. Examples are resistance thermometers, thermistors, voltmeter devices, differential transformers, photo emission cells, etc.

(iii) Based on Tendency of Signal - Depending on the tendency of the signals received at the output of the transducer, they are mainly of the following two types -

Analog Transducer - The analog transducer converts the input signal into an analog output signal. The output signal obtained from this is in the form of a continuous function over time. Examples - Thermistor, LVDT etc.
Digital Transducer - This transducer provides the output corresponding to the input in pulse form. This transducer can have any form of input signal, but only digital form is received as output. Example Digital Encoder.

Advantages of Electrical Transducer

Following are the major benefits of electrical Transducer

With its help, any type of energy can be amplified and attenuated in electrical form.
The energy of the transducer can be controlled with very little loss through electrical or electronic systems
With the help of a transducer, electrical energy can be transferred from one place to another
Due to the revolution in solid state electronics, large transducer circuits can be installed in a very small space through integrated circuits
Mechanization and control with electrical signals in transducers would be very easy
Solid state devices are used for amplification of electrical signals
Electrons are responsible for inertia in electrical transducers, so the effect of inertia is also reduced as the electron mass is reduced
In electric transducers the friction effect is very negligible
Electrical and electronic signals can be controlled with very little power with the help of electrical transducers

Convert the output of the transducer -

The measurement system uses transducers, signal conditioning and output devices. The output of the transducer cannot be received directly on the output device without conversion. Hence its output is modified or modified. The following are the main reasons for converting the output of the transducer -

To convert the output voltage and current of the transducer to digital coding
To balance the output of two or more transducers according to the already solved mathematical equations
amplify the transducer output directly.
nonlinear amplification of the transducer output, (v) to correct the input and thermal-electrical error
To perform impedance equalization
To equalize and boost the transducer limits