How Does a Transducer Work
A transducer can be thought of as being a device which can sense and relay a signal, but in any case, the form of the energy must be changed. This is the primary characteristic of a transducer. Otherwise, it would just be a device that relays signals. So how does a transducer work?
Examples of Transducers
In the simplest definition: A transducer is a device that changes one form of energy to another. Sound to electricity, for example—which is what a microphone does, or electricity to sound—which is the function of a speaker. Yes, a speaker is essentially an electromechanical transducer and it uses magnets to change electrical pulses into audible vibrations.
Note that, in the word “electromechanical,” the “electro” refers to the type of energy coming into the speaker, which is electrical energy, and the “mechanical” refers to the type of energy coming out of the speaker. Another example is if the source of energy comes from underwater and the end result desired is an electrical signal. In this case, you’re talking about an acoustic hydrophone.
For Detecting Changes
A transducer can be used to detect pressure (such as air pressure), temperature, flow, acceleration, velocity, and the like, from a particular location where such things can be sensed and relayed to another place, such as a control room, where the resulting signal can be seen and interpreted. Modern day aircraft, for example, use transducers mounted in their fuselages and wings to give the pilots in the cockpit information on how high they’re flying and how fast they’re flying.
The signal that the transducers receive usually varies quickly. Think of the wind buffeting an airplane’s wing, for example. There will be small, local gusts or eddies throughout the wing, and even over only several seconds, the wind pressure on one part of the wing will change quickly—up and down. This creates what is called “noise,” and noise creates a very messy signal. To clean up this signal, a signal-conditioning unit is used to filter it, and, if the signal is too weak, to amplify it so that it can be easily seen by whomever’s watching.
Physiological Transducers
It’s also interesting to note that our biological senses are essentially transducers. Whatever the sense—touch (a mechanical input), hearing (a mechanical input, based on the frequency of sound waves in the air), smell (a chemical input) and sight (a light energy input)—these are immediately converted to electrical signals which our brain can make sense of, so that we can sense and interpret the world at large.
The next time you wonder how “does a transducer work,” keep in mind that it can be as simple as a microphone and that it can be as complicated as human sight!