Author: John Mulindi
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Basic Features of Power Semiconductor Controlled Drives
Power electronics deals with the applications of solid state electronics for the control and conversion of electric power. The conversion systems require switching power semiconductor devices on and off. The key components of an electric drive controlled by a power semiconductor converter are illustrated in the figure below: The converter regulates the flow of power…
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How to calibrate a dc voltmeter
An instrument may be calibrated by comparing its reading with that of a more accurate instrument when both are measuring the same quantity. The more accurate instrument is used as a standard for comparison purposes. The figure below illustrates the method for calibrating a dc voltmeter. An appropriate dc voltage level is applied from the…
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How to calibrate a dc ammeter
The figure below shows two dc ammeters connected in series, so that they are both measuring the same current. An ammeter may be calibrated by comparing it to a more accurate (standard) ammeter measuring the same quantity. The accuracy of the standard instrument should be at least four times better than the instrument to be…
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What are PLC-Based Water Treatment Plants?
Most of the water treatment plants in the previous decade were manually operated. However, they were automated to a certain degree using relays or electrical control panels but the system was not reliable and required a lot of space. In this modern era, water treatment facilities are automatically operated using PLC or Programmable Logic Controllers…
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Analog Proportional Controller
An analog controller typically employs op-amps to provide the necessary gain and signal processing. Let’s consider the flow control system below: In the system above, the controller’s function is to maintain the flow of a liquid through a pipe at 6 gallons/minute. This system consists of: The flow valve is operated with a signal…
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Tuned Amplifier Applications
A tuned amplifier operates over a band of frequencies centered on a resonant frequency. Its two main requirements are to provide high gain and good selectivity. We have several applications in telecommunications systems where it is necessary to amplify a narrow band of frequencies centred on one frequency. A typical example is shown in the…
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Applications of Filters in Telecommunication Systems
Electronic filters have many applications in the telecommunication and data communications industry. For example, they are used in a multichannel communication system employing a technique known as time-division multiplexing (TDM). In this system, several channels are transmitted through a medium such as optical fiber or through a co-axial cable or waveguide. Multiplexing means combining several…
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How does diesel engine generate electricity?
What is power plant? A power plant is a facility that converts the energy of fuels into electricity. The term power plant is often used to refer to a coal-fired, nuclear, natural gas, or oil-fired electric generating station. Power plants are typically large industrial facilities that provide enough electricity to supply an industrial town or…
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Toggle Switches
Toggle switches are available in various contact configurations. Each switch consists of one or more poles, where each pole is actually a separate switch. The switch contact configurations include: Single-pole/single-throw switch (SPST) This is the simplest switch. It has a single set of contacts that can either open or close. Its contact configuration is illustrated…