Difference between Active Transducer and Passive Transducer

What Is The Difference between Active Transducer and Passive Transducer? . There are different physical forces which we cannot measure easily such as pressure, displacement, humidity and many more. But to measure all these forces, a device is necessary which can change the physical quantities into easily assessable energy. This conversion can be done by using the transducer. These devices play an essential role in fields like control engineering, instrumentation, etc. Any kind of energy must be changed while processing from one form to another to create the communication from one modification sector to a different one. This article discusses an overview of the active and passive transducer.

Read More : What Is the Difference Between AC and DC Motors?

What is Transducer?

The transducer is one kind of electrical or electronic component, and the main function of this is to change one kind of energy into another. The best examples of transducers are a microphone, a solar cell, an incandescent light bulb, and an electric motor. As these transducers play a key role while changing the energy from one form to another form.

What is an Active Transducer?

The type of transducer which can generate an output signal in the form of voltage or current without the need of external power supply is known as active transducer. In other words, the active transducer is one that requires an additional power supply to work.

Since the active transducer can generate its output itself, hence it is also known as self-generating transducer. The active transducer obtains the energy required to produce the output signal from the physical quantity that is to be measured.

A common example of active transducer is the piezo electric crystal. This is because when an external force is applied to the piezo electric crystal, it produces an output voltage, and for this it does not require any additional source of power. Another common examples of active transducers are tachogenerators, thermos-couples, etc.

Read More : What Is the Difference Between Sensor and Actuator?

Advantages of Active Transducers

• No external power is required. The active transducers work separately; that is why their construction is easier.
• Self-generating: These transducers have the capability of directly converting the measured quantity into an electrical form.
• Low cost: Compared to passive transducers, it is relatively easier to construct and therefore most often cheaper as well.

Disadvantages of Active Transducers

• Low resolution: Due to their ability to produce an output signal that is proportional to a measured parameter Active transducers have lower resolution as compared to passive transducers.
• Limited accuracy: It is also essential to remark that the accuracy of active transducers is less as compared to passive types.

What is a Passive Transducer?

The type of transducer that requires some additional source of power to produce the output is known as passive transducer. Therefore, a passive transducer requires an external power source to work. Passive transducers generate output signals when electrical parameters such as resistance, inductance, and capacitance change.

A common examples of a passive transducer is a linear potentiometer that is used to measure the displacement. It is a passive transducer because it requires an external power source to work, i.e. to measure linear displacement. Another example of passive transducer is a thermistor.

After discussing about the basics of active transducer and passive transducer, let us now discuss the key differences between them.

Read More : What Is the Difference Between Analog and Digital Multimeter?

Advantages of Passive Transducers

• High resolution: Another difference is that passive transducers are capable of yielding a higher accuracy due to their ability to detect small changes in physical quantities.
• Precise measurements: These transducers can ideally measure small changes in output, and therefore, they’re used where accuracy is needed.

Disadvantages of Passive Transducers

• External power required: Because passive transducers require the supply of external power, their design becomes complicated.
• More complex: Because they require extra circuitry and power control in their function, passive transducers are usually more complex in design than active transducers.

Differences between Active and Passive Transducer

Read More : Difference Between Single Phase and Three Phase Transformer

The main difference among the active and passive transducer are listed below.

Active Transducer	Passive Transducer
An active transducer can be defined as, a transducer which gives the output in different forms like current or voltage without using any exterior source of energy.	The passive transducer can be defined as the internal parameters of transducer like resistance-capacitance as well as inductance are changed due to the input signal.
The working principle of this transducer is, it uses the measured source to draw the energy.	The working principle of this transducer is, it uses exterior power to change the transducer’s physical properties.
The extra energy source is not necessary	It requires an extra energy source.
The resolution of this transducer is low	The resolution of this transducer is high
The designing of this transducer is very simple	The designing of this transducer is complicated
The output signal of this transducer can be generated from the signal which is to be calculated.	The output signal of this transducer can be obtained by receiving the signal from the exterior power source.
The best examples of this transducer mainly include PV cell, thermocouple, etc.	The best examples of this transducer mainly include a differential transformer, resistance strain, etc.
This transducer provides electric current otherwise voltage straight in reply to ecological stimulation.	It provides some change within passive electrical amount like resistance, capacitance, and inductance based on the simulation result.

Thus this is all about an overview of what is an active and passive transducer, and differences between them. From the above information finally, we can conclude that these types of transducers can change the physical energies into easily calculated energies. The active transducer changes the energy without using the auxiliary power supply whereas the passive transducer uses the exterior power supply for the conversion of energy.

Read More : Difference Between Schottky Diode and Shockley Diode

Comparison Between Active and Passive Transducers

Power Source

One of the key differences between active and passive transducers is the external power source. Active transducer does not require an external power source while passive transducers do.

Output

The output of the active transducer is in the form of a voltage or current signal. While the output of the passive transducer is in the form of a change in resistance, capacitance and inductance.

Resolution

The active transducer has low resolution and it is less sensitive to small changes. While passive transducer has high resolution and more sensitive to small changes due to external sources. The resolution is also adjustable by varying the external source.

Amplifier

The active transducer generates a very low power signal thus it requires an amplifier while the passive transducer does not require an amplifier.

Design

Active transducers have a very simple design and construction. While passive transducers are very complex to design and manufacture.

Cost

Active transducers are inexpensive and very economical due to their simple design. While passive transducers are expensive.

Examples

• Active transducers are thermocouples, piezoelectric crystals, photovoltaic cells, tachogenerator, etc.
• Passive transducers are potentiometers, thermistors, variable capacitors, etc.

Read More : What is the Difference Between Clipper and Clamper Circuits?

FAQs

What are examples of active transducers?

An active transducer is a transducer that includes its own power supply; examples of active transducers are a thermocouple and piezoelectric crystals.

Why are passive transducers more accurate?

Passive transducers are more accurate as compared to the active transducers because passive transducers do not require any external power to work as they only convert one form of energy into another form of energy; hence, they can measure small variations of physical quantities as compared to the active transducers.

Which type of transducer is more cost-effective?

When compared to passive transducers, active transducers have lower costs of production, mainly because their construction is simpler and does not require any kind of power supply.

What are the applications of active and passive transducers?

As a result, active transducers are suitable in applications where simplicity and cost are considerations, while passive transducers are used in measurement systems that require high accuracy.

Related Topics

• Voltage Stabilizer vs. Voltage Regulator: Key Differences Explained

• Transistor vs. Thyristor (SCR)

• Amplifier Vs. Operational Amplifier

• Static Balancing vs. Dynamic Balancing: Key Differences Explained

• What is the Difference Between Fuse vs. Circuit Breaker?

• Batteries in Series vs Parallel: The Ultimate Guide to Choosing the Best Configuration

• Blower vs. Fan: Key Differences, Uses, and Pros & Cons

• What Is the Difference Between ELCB vs. RCCB? A Detailed Guide