March 24, 2015

Transducers are devices that convert different forms of energy from one to another; such as physical quantity into a proportional electrical quantity such as voltage or an electrical current. This can be measured in a multitude of ways, such as temperature, or pressure. There are several different types of transducers, many relating to everyday life such as light bulbs, thermometers, and microphones. There are two main types of Transducers. One type of Transducer is based on Quantity to be measured. This is where you will find Temperature, Pressure, Displacement, and Flow Transducers. Another type is based on the Principle of Operation. These include Photovoltaic, Piezoelectric, Chemical, Mutual Induction, Electromagnetic, Hall Effect, and Photoconductors.
There are also Active and Passive Transducers. The difference between these two is their source of power. Active transducers do not require any power to operate, while passive transducers need an external power source to operate. Active transducers work off of energy conversion. This means they produce an electrical signal equal to the physical quantity of use. A common active transducer is a thermocouple. Passive Transducers are more complex when requiring power. The output signal they form come in different variations, these could me capacitance or another electrical parameter. This electrical source needs to be converted to an equivalent current. An important thing to remember when dealing with any type of transducer is that they are not 100% efficient, meaning during the conversion process of electric, some energy is lost, which would result in heat. A common household example is 100 watt bulb found in your home. Not all 100 watts is in the form of light, much of that power is heat given off.