An inquisitive child would ask a lot about what he sees around the house. While most of those questions may seem silly to adults, others simply make sense, and even make adults wonder for themselves. For instance, questions like “How does a microphone make one’s voice louder than normal?” or “Why is a flat iron hot?” can leave grownups scratching their heads.
Well, if you want to learn about how most of your home appliances work so that you can give your kids an accurate and informative answer whenever they ask, read on. Most of your home appliances work with the help of a device called a transducer, which is designed to convert one form of energy to another. For example, a speaker uses a transducer to convert electrical energy to sound waves.
Transducers can be categorized according to principle of operation, external power source requirements, and measurement quantity. In terms of operation, transducers can be classified as photovoltaic (commonly found in solar cells, which convert heat energy into electric energy) and piezoelectric (i.e. those that produce sound waves above the frequency audible to the human ear).
In terms of the need for external power sources, transducers fall under two types: active and passive. Active transducers do not need any power source to operate. The best example for this is a thermocouple. A passive transducer, on the other hand, requires an external power source. A photocell, for instance, will only produce photos when it makes contact with light.