O transducer is a device that transforms one type of energy into another. It can convert, for example, a physical magnitude such as position, velocity, temperature, light, among others, in a normalized electrical signal. This property is mainly used by sensors.
Operating diagram of a transducer
An example of a transducer is the MIC, which transforms sound energy into an electrical signal. Another example is the loudspeaker, which works inversely to the microphone, converting electrical signals into sound energy.
Transducers and sensors are often treated as if they have the same function, but they actually have different roles. The sensor detects a physical variable, which can be pressure, temperature or the intensity of a force, and the transducer transforms that measurement into an easy-to-measure quantity. It transforms a temperature signal into an electrical signal, for example.
Although they are not the same device, transducers and sensors can often come integrated, so they end up being called only as transducers.
Transducers can be classified as:
Active: generate an electrical signal in response to a stimulus and do not need to receive external energy to produce an output signal;
liabilities: need to be excited by an external power source to produce an output signal;
Passive Transducer Operating Scheme
Simple: When transduction is done in only one stage, as is the case with a position sensor that produces a variation in electrical voltage in the presence of a magnetic material;
Compounds: when the transduction is done in several stages between the input and output signal of the physical magnitude, which, in turn, is transformed into intermediate quantities during the process, as shown in figure a follow:
Working diagram of a composite transducer
human body transducers
The human body is equipped with transducers, and an example is our vision: the retina has millions of cells photoreceptors that receive light energy and transform it into electrochemical impulses, which are then decoded by the brain.
Hearing is also an example of a human body transducer. The ear receives sound energy from vibrations in the air, and this energy is transformed into electrical signals in the inner ear, which in turn are transmitted by the nerve to the brain.
By Mariane Mendes
Graduated in Physics
