# Resistive Transducer Working and Its Applications

The resistive transducers are also known as resistive sensors or variable resistance transducers. These transducers are most frequently used for calculating different physical quantities like pressure, vibration, temperature, force, and displacement. These transducers work in both primary as well as secondary. But generally, these are used as secondary because the primary transducer’s output can work as an input to the resistive transducer. The output which is attained from it is adjusted against the amount of input & it provides the input value directly. This article discusses an overview of this transducer.

What is Resistive Transducer?

The resistive transducer can be defined as; the resistance of a transducer can be changed due to the effects of the environment.  Here, the resistance change can be calculated with the help of measuring devices like AC or DC. The main purpose of this transducer is to measure physical quantities such as vibration, displacement, temperature, etc.

he physical quantity measurement is fairly not easy. The physical quantities can be changed by using this transducer into variable resistance. By using the meters, it can be measured easily. The method of difference in resistance is extensively used within industrial applications.

This transducer works on both the primary & the secondary. The primary transducer converts the physical quantities to a mechanical signal whereas the secondary transducer converts to an electrical signal directly.

The major types of resistive transducer include potentiometers, resistive position transducers, resistive pressure transducers, thermistors, strain gauges, and LDR.

Working of Resistive Transducer

This is the most frequently used transducer to calculate pressure, temperature, force, displacement, vibrations, etc. To understand the working of a resistive transducer, the conductor rod is considered as an example of this transducer.

These transducers work on the principle of the length of a conductor which is directly proportional to the conductor’s resistance & it is inversely proportional to the conductor’s area. So, the denominated length of the conductor is ‘L’, the area is ‘A’ and resistance is ‘R’ and the resistivity is ‘ρ’.  It is stable for every material which is used in conductor construction.

R = ρL/A

From the above equation,

‘R’ is the resistance of the conductor.

‘A’ is the side view part of the conductor.

“L’ is the conductor’s length.

‘ρ’ – the resistivity of the conductor.

The transducer’s resistance can be changed because of the exterior environmental factors as well as the conductor’s physical properties.  The change in resistance can be measured using AC devices or DC devices. This transducer acts like a primary as well as the secondary transducer. A primary transducer is used to change the physical quantity to the mechanical signal whereas a secondary transducer is used to convert a mechanical signal to an electrical signal.

Resistive Transducer Circuit

The best example of this circuit is the sliding contact device. The circuit diagram of this is shown below. The sliding contact of this transducer mainly includes a long conductor whose length can be changed. One side of the conductor is connected whereas another side of the conductor can be connected to a brush/slider which moves through the conductor’s full-length.

The displacement of the object can be calculated by connecting it to the slider. Whenever energy is given to the object for moving them from its first position, then the slider moves with the conductor’s length.  So the length of the conductor will change to reflect on modify within the resistance of the conductor. A transducer like a potentiometer works on the sliding contact type principle which is used to calculate linear & angular displacement.

### Applications of Resistive Transducer

The applications of resistive transducer include potentiometer, resistance thermometer, strain gauges, thermistor, etc.

• These transducers are mainly used to calculate the temperature in several applications.
• The applications of resistive transducer include potentiometer, resistance thermometer, strain gauges, thermistor, etc.
• These transducers are used to measure displacement.
• The best examples of this transducer are potentiometers like rotator & translation. The resistance of these can be changed with the deviation within their lengths to measure the displacement.
• The semiconductor material’s resistance can be changed when the strain happens on it. This property can be used to measure force, displacement, and pressure, etc.
• The metal’s resistance can be changed due to temperature change. So this property can be used to calculate the temperature.
• The working principle of this is the thermistor materials temperature coefficient can be changed by the temperature. The temperature coefficient of the thermistor is negative which means this is inversely proportional to resistance.

The advantages of the resistive transducer include the following.

• These transducers give quick responses.
• These are available in different sizes and they have high resistance.
• The voltage otherwise current for both the AC & DC is suitable for calculating variable resistance.
• They are low-cost.
• The operation of these transducers is very easy and used in various applications wherever the necessities are not mostly severe.
• These are used to measure the huge amplitudes of displacement.
• Its electrical efficiency is extremely high and gives adequate output to let control operations.