Electrical transducer
transducers that convert physical quantities into electrical quantities
Mechanical transducer
Transducers that convert physical quantities into mechanical quantities
Electrical transducer is a device which performs the followings:
1. Sense non-electrical quantity (e.g. temp, sound, light) as input
2. Transforms the input signal into electrical signals (i.e. voltage, current) proportional to the input measurement parameters (sensed quantity) as output.
TRANSDUCER = SENSING ELEMENT + TRANSDUCTION ELEMENT
CLASSIFICATION OF ELECTRIC TRANSDUCER
1)Classification based on Physical Effect
2)Classification based on Physical Quantity
3)Classification based on Source of Energy
1)Classification based on Physical Effect
The first classification of Transducers is based on the physical effect engaged to convert the physical quantity to electrical quantity. An example, is the change in resistance (physical quantity) of a copper element in proportion to the change in temperature.
The following physical effects are generally used:
Variation in Resistance
Variation in Inductance
Variation in Capacitance
Hall Effect
Piezoelectric Effect
2)Classification based on Physical Quantity
The second classification of Transducers is based on the physical quantity converted i.e. the end use of the transducer after the conversion. For example, a Pressure Transducer is a transducer that converts pressure into electrical signal.
Following is small list of transducers classified based on the physical quantity and corresponding examples
Temperature Transducer – Thermocouple
Pressure Transducer – Bourdon Gauge
Displacement Transducer – LVDT (Linear Variable Differential Transformer)
Level Transducer – Torque Tube
Flow Transducer – Flow Meter
Force Transducer – Dynamometer
Acceleration Transducer – accelerometer
3)Classification based on Source of Energy
Transducers are also classified based on the source of energy. Under this category, there usually two types of transducers:
Active Transducers
Passive Transducers
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