Input/ Output Devices
A Linear Variable Differential Transformer, or LVDT for short, is an electromechanical position transducer (sensor) which provides accurate and frictionless positional feedback information about the linear mechanical position of an external force or object. As its name suggests, the linear variable differential transformer works on the same principle as the AC transformer but instead of…
As we saw in the previous input interfacing tutorial, an interface circuit allows one type of circuit to be connected to another type of circuit that may be of a different voltage or current rating. But as well as interfacing input devices such as switches and sensors we can also interface…
The Thermistor is a solid state temperature sensing device which acts a bit like an electrical resistor but is temperature sensitive. Thermistors can be used to produce an analogue output voltage with variations in ambient temperature and as such can be referred to as a transducer. This is because it creates a…
Interfacing is the method of connecting or linking together one device, especially a computer or micro-controller with another allowing us to design or adapt the output and input configurations of the two electronic devices so that they can work together. But interfacing is more than just using the software program of…
Electrical DC Motors are continuous actuators that convert electrical energy into mechanical energy. The DC motor achieves this by producing a continuous angular rotation that can be used to rotate pumps, fans, compressors, wheels, etc. As well as conventional rotary DC motors, linear motors are also available which are capable of…
Sound is the generalised name given to “acoustic waves”. These acoustic waves have frequencies ranging from just 1Hz up to many tens of thousands of Hertz with the upper limit of human hearing being around the 20 kHz, (20,000Hz) range. The sound that we hear is basically made up from…
We have seen in this section on Input/Output Devices that transducers are devices which convert one form of energy into another. For example, microphones convert sound waves into electrical signals, motors convert electrical energy into mechanical energy, or light bulbs convert electrical energy into light. Either way, Transducers in their many forms can be…
The linear solenoid works on the same basic principal as the electromechanical relay seen in the previous tutorial and just like relays, they can also be switched and controlled using bipolar transistors or MOSFET’s. A “Linear Solenoid” is an electromagnetic device that converts electrical energy into a mechanical pushing or pulling force…
These types of temperature sensor vary from simple ON/OFF thermostatic devices which control a domestic hot water heating system to highly sensitive semiconductor types that can control complex process control furnace plants. We remember from our school science classes that the movement of molecules and atoms produces heat (kinetic energy)…
Thus far we have seen a selection of Input devices that can be used to detect or “sense” a variety of physical variables and signals and are therefore called Sensors. But there are also a variety of electrical and electronic devices which are classed as Output devices used to control or operate some external physical…
As their name implies, Position Sensors detect the position of something which means that they are referenced either to or from some fixed point or position. These types of sensors provide a “positional” feedback. One method of determining a position, is to use either “distance”, which could be the distance between two…
A Light Sensor generates an output signal indicating the intensity of light by measuring the radiant energy that exists in a very narrow range of frequencies basically called “light”, and which ranges in frequency from “Infra-red” to “Visible” up to “Ultraviolet” light spectrum. The light sensor is a passive devices that…