Transducers Flashcards
An electronic device that converts energy from one form to another.
Transducers
Process of converting energy from one form to another
Transduction
Output obtained from transducers is always in the _____ form.
Electrical
What are the main types of transducers?
Active Transducer
Passive Transducer
Does not require any power source in order to function
Active Transducers
Needs an external power source to operate
Passive Transducer
Is a passive transducer which varies the voltage of the electrical output from the cell when a torque is applied
Torque Transducer
Is a passive transducer which will vary the resistance of the cell when light falls on it.
Photocell
Is a passive transducer used to measure stress or pressure
Bonded Strain Gauge
Types of Transducers Based on Quantity to be Measured
Temperature Transducers
Pressure Transducers
Displacement Transducers
Oscillator Transducer
Flow Transducers
Inductive Transducers
Converts the thermal quantity into any physical quantity
Temperature Transducers
Types of Temperature Transducers
-Contact Temperature Sensor Types
-Non-Contact Temperature Sensor Types
-Thermistor
-Resistance Thermometers
-Thermocouples
-Integrated Circuit Temperature Transducers
The sensing element in this is in direct contact with the thermal source
Contact Temperature Sensor Types
The sensing element in this is not in direct contact with the thermal source
Non-Contact Temperature Sensor Types
What heat transfer is used in Contact Temperature Sensor Types?
Conduction
What heat transfer is used in non-contact sensor types?
Convection
The resistance changes with the change of temperature
Thermistor
Precision temperature sensors made from high-purity conducting metals
Resistance Thermometers
Resistance of Thermistors
0.5 to 0.75M
Consists of 2 junctions of dissimilar metals, such as copper and constantan that are welded
Thermocouples
A phenomenon in which a temperature difference between two dissimilar electrical conductors or semiconductors produces a voltage difference between the 2 substances
Seebeck Effect
transducer that use the temperature sensing element with monolithic electronic circuits as a combination for the measurement of temperature.
Integrated Circuit Temperature Transducers
Is a temperature sensitive zener diode
LM335
Used to measure pressure
Pressure Transducer
Measures large displacements such as brake pedal travel or pneumatic actuator displacement
Linear Variable Dependent Transducers (LVDT)
Used to measure force, pressure or displacement by converting it to a voltage.
Oscillator Transducer
Parts of an Oscillatory Transducer
Mechanical Linkage
Oscillator
Frequency Modulator
Force Summing Member
Used to link the input quantity to the secondary transducer
Mechanical Linkage
Used to generate desired frequency
Oscillator
Used for modification of output frequency from the oscillator for telemetry purpose
Frequency Modulator
Is used to change the capacitance or inductance of an LC oscillator circuit
Force Summing Member
Used to measure air and liquid flow velocity
Flow Transducers
Works by measuring the amount of a liquid, gas, or steam flowing through or around the flow meter sensors
Flow Meter
Types of Flow Meters
Capillary Thermal Mass
Immersible Thermal Mass
Vortex Shedding
Transit-Time Ultrasonic
Thermal heat is transferred between gas passing through a very small tube and a set of resistance temperature
detectors (RTDs) to measure the mass flow of the gas.
Capillary Thermal Mass
uses the thermal heat
transferred from a heated sensor immersed in the
flow to measure the mass flow of the gas
Immersible Thermal Mass
Measures mass and/or
volumetric flow of liquids, gases, and steam using
vortices shed from a sensor immersed in the flow and
a computed fluid density
Vortex Shedding
measure speed of a fluid
passing through a pipe using ultrasound.
Transit-Time Ultrasonic
Is the self-generating
type otherwise the passive type transducer.
Inductive Transducer
Types of Inductive Transducers
Simple Inductance
Two-coil Mutual Inductance
A simple single coil is used as a transducer
Simple Inductance
two different coils are arranged
Two-coil Mutual Inductance
Types of Transducers Based on Principle of Operation
Photovoltaic
Piezoelectric Transducer
Chemical
Mutual Induction
Electromagnetic
Hall Effect
Photoconductor
Converts light energy to electrical energy
Photovoltaic
Classification of Photoelectric Transducers
Photo-emissive Cell
Photovoltaic Cell
Photo-conductive Cell
Photodiode
Phototransistor
Is based on the emission of
electrons when the transducer is exposed to sunlight.
Photo-emissive Transducer
Consists of an anode
rod and a cathode plate enclosed in a vacuum glass tube.
Vacuum Phototube
It is the most popular and most widely used photo-emissive transducer.
Photomultiplier
Is also known as a solar
cell. It converts electromagnetic radiation into an electrical signal.
Photovoltaic Cell
It works on the principle of photoconductive effect.
Photo-conductive Cell
acts as a light-sensitive
device and converts the illuminated light into
an electrical signal.
Photodiode
Are similar to regular NPN
or PNP or FET transistors with three layers but with a light-sensitive base region.
Phototransistor
is a device that uses
the piezoelectric effect to measure changes in acceleration, pressure, strain,
temperature or force by converting this energy into an electrical charge.
Piezoelectric Transducer
Behaves in the
reverse manner of the piezoelectric sensor.
It is the one in which the electric effect will
cause the material to deform
Piezoelectric Actuator
Who discovered piezoelectric effect?
Pierre and Jacques Curie
states that when mechanical stress or forces are applied on quartz crystal, produce electrical charges on the quartz crystal surface.
Piezoelectric Effect
is anything that produces sound.
Buzzer
depends on acoustic cavity
resonance to produce an audible beep.
Piezoelectric Buzzer
It transforms the energy into some form of analytical signal.
Chemical
is a device that measures and detects chemical qualities in an analyze and converts the sensed chemical data into electronic data.
Chemical Sensor
Is the component of the
chemical sensor that comes into physical contact with the analyze
Receptor
In this type, two coils are used. One for generating excitation and another for output.
Mutual Induction
Is a transducer for non-contact
acoustic wave generation and reception in conducting materials.
Electromagnetic acoustic transducer (EMAT)
It is used for measuring the magnetic field by converting the field into an emf
Hall Effect
It converts the magnetic field into an electric quantity, readily estimated by the analog and digital measures.
Hall Effect Transducer
It is employed to convert light energy into electrical energy. It is composed of semiconductor substance.
Photoconductor
