Electrical Transducers and Their Types

An electrical transducer is a component that is able to transform physical quantities into voltage or electric current, allowing for measurements to be made in the form of electrical signals. Electrical transducers can measure many properties, often being used for pressure, temperature, level, displacement, and much more. As the output signal is always proportional to the quantity that the device measures, transducers are quite reliable and useful for the applications that they serve.

Modern industrial applications are quite dependent upon instrumentation, that of which is used for the measurement and management and various operational variables. With instrumentation, aspects such as displacement, temperature, flow, angle, and level may all be managed with ease. For basic instrumentation systems, transducers are a crucial part that is relied upon for the conversion of energy.

Depending upon one’s needs, there are a number of transducer types that are classified by the quantities or attributes that they measure. In general, the most common types include temperature transducers, pressure transducers, displacement transducers, oscillator transducers, flow transducers, and inductive transducers. Such devices may also be categorized based on their principle of operation, common forms being photovoltaic, piezoelectric, chemical, mutual induction, electromagnetic, hall effect, and photoconductor transducers. As a final way of classifying transducers, such components may also be determined based on whether or not there is a required external power source.

If a transducer is capable of transforming quantities into measurable electrical signals without the need of an external power source, the component is known as an active transducer. With a fairly simplistic design, the self-generating device draws energy from the measurement system when it makes a measurement, and the generated output is typically small. Active transducers can come in a variety of types, the most common being the piezoelectric, photoelectric, and thermoelectric transducer.

For transducers that rely on external power sources, however, such devices are known as being passive. Generally, such variations generate their output signal in the form of variations in resistance, capacitance, or another type of electrical parameter. Then, this output is proportionately converted into a voltage signal or electrical current which can be measured. A photocell is a common example of a passive transducer, and such devices are capable of varying the resistance of the cell when exposed to light. With the assistance of a bridge circuit, the resistance change can be transformed into a proportional signal so that the photocell can accurately measure the intensity of light.

With their standard set of capabilities, transducers are often compared to sensors. While sensors are commonly employed for the means of detecting physical changes within a space, transducers serve to convert these changes or measurements into electric signals. Their similarity comes from the fact that sensors are a type of transducer, creating signals based on their detection which may then be used by a control system, information system, or a type of telemetry. Actuators are also commonly compared as well, being capable of receiving a source of energy to act upon the environment in a specific fashion.

1. steven helmer
2. Posted on August 15, 2021
electronics