Author: John Mulindi
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Capacitors, Capacitance and Charge
Introduction to Capacitors A capacitor is an electrical device that is used to store electrical energy. A capacitor consists of two metal plates separated by an insulator called a dielectric. It stores electricity in the form of an excess of electrons on one plate and a deficiency on the other. In this state, the capacitor…
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Pneumatic Actuators
Valves cannot control a process by themselves. Manual valves require an operator to position them to control a process variable. Valves that must be operated remotely and automatically require special devices to move them. These devices are called actuators. Actuators may be pneumatic, hydraulic, electric solenoids or motors. In this article we look at specifically…
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Radio Frequency (RF) and Microwave Spectral Analysis
The display of electromagnetic radiation as a function of wavelength is termed to as electromagnetic spectrum. Based upon the wavelengths, the spectrum is divided into various frequency bands as illustrated in the figure below: With the rapid advancement of wireless technology and satellite sensor technology, there is need for more and more accurate field measurements…
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What is a Mechatronics System?
Mechatronics Mechatronics can be defined as a rapidly developing interdisciplinary field of engineering dealing with the design of products whose function relies on the integration of mechanical and electronic components coordinated by a control architecture. The primary disciplines that are important in the design of mechatronic system include mechanics, electronics, controls and computer engineering. A…
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The Basic Principle of Operation of an Oscillator
An oscillator is the basic element of ac signal sources and generates sinusoidal signals of known frequency and amplitude. The main applications of oscillators are as sinusoidal waveform sources in electronic measurements. Oscillators can generate a wide range of frequencies (from a few Hz to many GHz) as per the application’s requirement. Even though, an…
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Series and Parallel Circuits
Series Circuits The figure below shows three resistors R1, R2, and R3 connected end to end i.e. in series with a battery source of V volts. Since the circuit is closed, a current I flow and the voltage across each resistor may be determined from the voltmeter readings V1, V2, and V3. In a series…
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Factors to consider when selecting a Motor for a particular application
When selecting a motor for a specific industrial application, there are several factors and specifications that you should consider. We look at these factors that will guide you when choosing the appropriate motor for your industrial use. The following are some of the key questions or factors that you should consider when choosing the suitable…
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Performance Characteristics of Digital Measurement Instruments
In this article, we discuss the performance characteristics of digital instruments i.e. Resolution Accuracy Linear errors Settling time Temperature sensitivity Monotonicity Resolution This is defined as the smallest increment in voltage that can be discerned. It is the reciprocal of the number of discrete steps in the Digital to Analog (D/A) converter input. Resolution depends…
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Pulse Width Modulation (PWM) Speed Control of a DC motor
We can control the speed of a motor using an open loop control or closed loop control strategy. The open loop control is the simplest form of motor control; here we simply set the drive voltage value and the motor characteristics and the load determines the operating speed & torque. But you will find that…
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Root-mean-square (r.m.s.) value
We know that a current passing through a resistance has a heating effect, the magnitude of which we measure in watts, that is power is given by This shows that power (or heat) dissipated in a resistance is proportional to either square of the current or the voltage. Related: The Basics of Electric Circuits Consider…