Author: John Mulindi
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Key Instruments Used By Electronics Engineers
Multimeter This is also called volt-ohm-milliammeter (VOM). It is a general purpose instrument having the circuitry and switching arrangement for measuring ac/dc voltage or ac/dc current or resistance. It is simple, compact and portable instrument because the only power it uses is the battery for the ohm-meter. Multimeters can be analog or digital type. Multimeters…
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Key Facts about Thyristor DC Motor Drives Operation
For motors up to a few kilowatts the armature converter draws power from either a single phase or 3-phase utility supply. For large motors, 3-phase power supply is preferred because the waveforms are much smoother although traction uses single-phase with a series inductor to smooth the current. A separate thyristor or diode rectifier is used…
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Step by Step Guide: How to Check and Test a Power Transformer
Testing of power transformers is continuous monitoring of faults in all units of such equipment and their timely removal after detection. All this is achieved with one objective continuation of the continuous activity of a significant node in the power supply system of many energy consumers. A variety of tests are used to determine the…
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The Basics Facts about Photons
Photons are the elemental units of electromagnetic spectrum. For example, white light is composed of a number of different kinds of photons, some are red photons, some are blue photons, etc. Note that, there is no white photon; instead the combination of the various colored photons when they interact with your eyes, your brain perceives…
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General Principles of Radio Broadcasting, Transmission and Reception
Radio communication is the radiation of radio waves by the transmitting station, the propagation of these waves through the space and their reception by the radio receiver. The figure above shows the general principles of radio broadcasting, transmission and reception. We can divide the entire arrangement into 3 major sections, namely: Transmitter This equipment is…
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Introduction to Radio Broadcasting, Transmission and Reception
In radio transmission, it is necessary to send audio signal e.g. music, speech, etc. from a broadcasting station over great distances to a receiver. This communication of audio signal does not employ any wire and is sometimes called wireless. The audio signal cannot be sent directly over the air for appreciable distance. Even if we…
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The Fundamentals of Oscillators in Communication Systems
A communication system consists of an input device, a transmitter, a transmission medium, receiver and output device. The input device can be a computer, sensor or oscillator, depending on the application of the system, while the output device could be a speaker or computer. The input device and transmitter makes up the source section. The…
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Back emf and Torque Equations of a DC motor
The effect of the force in a magnetic field may be used to cause the rotation of a motor armature. A single loop of a conductor shown in the diagram above has its ends connected to a simple commutator; which comprises two copper segments insulated from each other. The commutator and loop are fixed to…
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Digital vs. Analog Instruments
Electronic instruments mainly voltmeters used either transistor or vacuum tubes. The later one is called The Vacuum Tube Voltmeter (VTVM) and the former one is called the Transistorized Voltmeter (TVM). In almost every field of electronics, VTVMs have been replaced by TVMs because of their numerous advantages. In TVM, due to the absence of a…
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Integral (Reset) Control Systems
Integral (Reset) control Reset/Integral control describes a controller in which the output rate of change is dependent on the magnitude of the input. Specifically, a smaller amplitude input causes a slower rate of change of the output. This controller is termed to as integral controller because it approximates the mathematical function of integration. This integral…