Fig. Capacitive transducers (source: directindustry.com) Capacitive Transducers The capacitive transducer is the capacitor with variable capacitance. The capacitive transducer consists of two parallel metal plates that are separated by the dielectric material such as air. We are familiar with the equation of capacitor which is given as In a normal capacitor, the … Read more
What is an analog-to-digital converter? An analog-to-digital converter (ADC) is a system that converts an analog signal to a digital signal. For example, a sound picked up by a microphone into a digital signal. The output of a microphone, the voltage at a photodiode or the signal of an accelerometer are the examples of the … Read more
Figure. RVDT In the previous article, we have learned about Linear variable differential transformer (LVDT). Rotary Variable Differential Transformer (RVDT) is a variation of LVDT and used to sense angular displacement. It is a passive transducer. In short, RVDT provides a variable alternating current (AC) output voltage that is linearly proportional to the angular displacement … Read more
In Inductive transducers, the basic principle is that self-inductance of a single coil or the mutual inductance between two coils is changed by a quantity to be measured i.e. measurand. Usually, the measurand could be a rotary or linear displacement, force, pressure, torque, velocity, acceleration, and vibration. For example, LVDT is an inductive transducer which … Read more
Modulation The term modulation means ‘to change‘ or ‘to modify‘. Modulation is the process of transmission of the information signal (low-frequency audio signal) using a high-frequency carrier signal. Modulation is the basic requirement for transmitting the message signal through free space. Modulating Signal The information bearing signal is called the modulating signal. Modulated signal The signal … Read more
Frequency Modulation It is the process in which the frequency of the carrier signal is varied by the modulating signal while the amplitude remains same. It is different from Amplitude modulation as there is amplitude variation. Let carrier wave be ec = A Sin (ωct + φ) = A Sin (fct + φ) fc = carrier wave … Read more
Amplitude Modulation(AM) The process of varying amplitude of the high-frequency or carrier wave in accordance with the intelligence (code, voice or music) to be transmitted, keeping the frequency and phase of the carrier wave unchanged, is known as the amplitude modulation. Modulating Signal The information bearing signal is called modulating signal. Modulated signal The signal … Read more
A sensor producing an electrical output, when combined with some interfacing hardware is termed to be an intelligent sensor. Intelligent sensors are also called smart sensors, which is a more acceptable term now. Sensors + Interfacing hardwares = Smart sensors This type of sensor is different from other types of sensors because it carries out … Read more
In many applications such as audio applications, it is useful to represent a signal in terms of sample values taken at appropriately spaced intervals. The signal can be reconstructed from the sampled waveform by passing it through an ideal low pass filter. In order to ensure a distortionless reconstruction, the original signal must be sampled … Read more
So far we have seen different types of pulse modulation. In this article, we are going to talk about Pulse Code Modulation (PCM). Pulse Code Modulation (PCM) Pulse Code Modulation (PCM) is a different type of pulse modulation because it is a digital process. Though it uses sampling techniques. The PCM generator produces a series of … Read more