The system in the diagram above conasts of a microphone, an amplifier and a loudspeaker. The microphone detects the sound waves and transforms them into an electrical signal. The amplifier receives the signal and increases its strength Finally, the amplified electrical signal is transmitted to the loudspeaker, that converts it back into sound IF the microphone weren't included in the system. the amplifier couldn't handle the sound. Either way, without a loudspeaker we wouldn't hear a louder sound despite the amplification stage. The whole process is possible thanks to transducers, which allow the performance of useful tasks or functions, because they convert one physical quantity to another physical quantity, or one form of energy into another. Inparticular, electrical transducers convert physical quantities like sound. speed or light, minto trasportare ingres while mechanical transducers convert deplacement sebstameran Anput transducer output transduce trasduttore di unita electrical quantities. physical quantities into mechanical quantities,like displacement, pressure or force. INPUT AND OUTPUT TRANSDUCERS In addition, transducers can be classified as input transducers or sensors and output transducers or actuators. In simple terms, sensors convert physical events into electrical signals, whereas actuators convert electrical or other forms of energy into physical events. In the example in the Warm up, the microphone works as the input transducer while the loudspeaker is the output transducer. Transducers are part of bigger systems: they are essential in monitoring and control systems. If these systems didn't have transducers to provide input and output data, they wouldn't be able to interact with the surrounding environment. Such interaction could be anything like reading the status of a signal from a switch or triggering a particular output to light up an LED. SENSORS Sensors are transducers that can 'sense' a wide range of different energy forms,such as movement, electrical signals, thermal or magnetic energy and others .They detect physical changes in the form of energy, and convert them into signals that can be understood and used by a processor or a human operator. Therefore, their role is crucial in the data acquisition process, which relies on the information provided by sensors to keep the desired parameters and processes under control. ACTUATORS Actuators can be seen as the opposite of sensors, as they are used in systems to perform output functions that can control and modify a process or the operations of a machine. Let's have a look at some examples. • Motors can provide movement. Everyday applications include the motor in a washingmachine it is switched on when the clothes are loaded for washing and switched off at the end of the wash Motors are also found in microwave ovens (to turn the food around), air-conditioning units (to drive the fan) and in industrial applications to move machinery and robotic arms. • Light bulbs and LEDs provide light, or indicate something, as in traffic lights. Lights are present in car dashboards to show if any of the car systems: has problems. In manufacturing processes, lights can signal ongoing activities or faults. • Buzzers can produce noise. For example, the buzzer in a microwave oven emits a signal when the food is cooked. Louder noises can be made using a siren or an electric bell, for example in burglar alarm systems. • Heaters are suitable for keeping the correct temperature of rooms, fluids or air in buildings and inside machines.
