Transducer
Transducers play an important role in the field of instrumentation and control engineering. Any energy in a process should be converted from one form into another form to make the communication from one rectification sector to another.
Transducer is a device which converts one form of energy into another form i.e,. the given non-electrical energy is converted into an electrical energy.
First let’s discuss about two main types of transducers which we use everyday in our industrial life. They are
Types of transducers:
There are two types of transducers, they are:
- Active transducers
- Passive transducers
Active transducers:
Active transducer is a device which converts the given non-electrical energy into electrical energy by itself. Thermocouple, Photovoltaic cell and more are the best examples of the transducers
Passive transducers:
Passive transducer is a device which converts the given non-electrical energy into electrical energy by external force. Resistance strain gauge, Differential Transformer are the examples for the Passive transducers.
Difference Between Active & Passive Transducer
The classification of transducers are made from the following basis:
Classification of transducers:
1. Based on the physical phenomenon,
- Primary transducer
- Secondary transducer
2. Based on the power type Classification,
- Active transducer
- Passive transducer
3. Based on the type of output the classification of transducers are made,
- Analog transducer
- Digital transducer
4. Based on the electrical phenomenon is a best Classification of Trasnducer,
- Resistive transducer
- Capacitive transducer
- Inductive transducer
- Photoelectric transducer
- Photovoltaic transducer
5. Based on the non-electrical phenomenon Classification of transducer,
- Linear displacement
- Rotary displacement
6. Based on the transduction phenomenon,
- Transducer
- Inverse transducer.
Factor to be considered while selecting transducer:
• It should have high input impedance and low output impedance, to avoid loading effect.
• It should have good resolution over is entire selected range.
• It must be highly sensitive to desired signal and insensitive to unwanted signal.
• Preferably small in size.
• It should be able to work n corrosive environment.
• It should be able to withstand pressure, shocks, vibrations etc..
• It must have high degree of accuracy and repeatability.
• Selected transducer must be free from errors.
Requirements of a good transducers
• Smaller in size and weight.
• High sensitivity.
• Ability to withstand environmental conditions.
• Low cost.