Measurement of electrical energy consumption today

Electromechanical energy counters were popular for more than 50 years, but today you can find them only in older houses or in low budget appliances because today electronic energy counters taking their place. And there are meny reasons to do so. For instance measurement accuracy, flexibility, multi-rate support, memory, statistics, remote reading and control, automatic register and so on. All these features can be buil in to one small chip which will serve with high reliability and low price. Lets see how energy (active power) consumption is measured. Active power which is required in form of alternate current (AC) can be calculated as average power over one period:  

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Oscilloscope probes for accurate signal measurements

Oscilloscope Probes Measuring signals with oscilloscopes may be challenging task especially high frequency ones. Without proper oscilloscope probes correct measurement of high speed time domain signals wouldn’t be possible. For high speed measurement you should consider signal parameters like amplitude, source impedance, rise time and bandwidth.   There is a wide variety of probes available – passive, active, current-measurement, optical, high voltage and differential. But let’s narrow discussion to probes that are used to measure signals with wide bandwidth and short rise times. There are also many variations on what probe is proper. As probes are potential load to measured circuit, it is important to know its sensitivity to resistive, capacitive or inductive loading. Incorrectly chosen probe (like high capacitance) can distort fast rising signal. Some circuits may not tolerate probes at all (high speed amplifiers).

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Reliable soldering with fluxes

Reliable soldering can be achieved by soldering clean surfaces. Usually surfaces are cleaned with abrasives and solvents, but after surface is cleaned surface immediately oxides especially when heated. During oxidation surface is covered by thin oxide film which prevents solder from contacting to metal. This is why flux is used in soldering process. In order to remove/deoxidize surface flux must be applied during soldering. Flux chemically removes surface oxide when heated and makes good metal to solder contact.   (Image source: https://www.tpub.com/neets/book4/12o.htm) There are several categories of soldering fluxes: Acid Flux (or commonly known fluxes: Zinc chloride, hydrochloric, ammoniac); Organic Flux; Rosin Flux. Each flux has their own specifics and may be used for different soldering technologies.

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What is worst-case timing analysis

Probably many of you PC hardware people have faced similar problems when assembling computer from different parts and it seemed to work properly. But under some circumstances system just crashes without any known reason. Even in my practice I had a sound-card that that works well, but time at the time it just crashes and then computer hangs. Of course I can blame drivers or operating system, but there is another probability that there can some timing failures occur. There are lots of complex production around us that may have a number of undefined failures due to lack of timing worst-case analysis. Failures may occur due to power supply fluctuations, thermal changes or other conditions. Worst-case analysis encounter all available information of condition variations that can affect performance of components. Worst-case analysis shows if electronic design meets specifications under variable conditions like temperature, voltage or other variables. Only detailed analysis can prove if design will work reliable under all operating conditions. An it is proved that it is much better to design reliable hardware than fix the problems later. In many ways worst-case analysis may be implemented in various manufacturing phases automatically. By including several simple tests may save lots…

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Electronic design and development process

There are so many ways of designing and developing of electronic devices, that it is hard to think which would fit your needs and desires. But there are common steps that probably fit in most cases that allow to implement the electronic system from top to bottom: 1) Defining the requirements of electronic system; 2) Collecting information on components to be used; 3) Evaluate the components with respect to the requirements; 4) Block diagram of preliminary design; 5) Do a preliminary timing and load analysis; 6) Define functionality logic; 7) Draw schematic using CAD software; 8) Do device design and simulation; 9) Perform detailed timing analysis and simulation and adjusting the design; 10) Double-check signal loadings, buffering as needed; 11) Document the design and generate a net list and bill of materials; 12) Generate layout of a printed circuit board; 13) Prototype design; 14) Program the memories and programmable logic for testing. 15) Debug and verify operations using oscilloscope/logic analyser or other debugging tools; 16) Update and complete documentation as the design changes. Those are general steps and the order may vary or even several tasks may be performed in parallel. Usually software is written in parallel with hardware design…

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Chemical effects of electricity

Electronics depend on chemistry more than you can imagine. In order to generate electricity there are many methods used, one of them is chemical. Remember batteries, where electricity is generated because of chemical reactions inside cell. Also in conductors like liquids and gases electricity is carried not by electrons as it is in solid constructions(copper, aluminum, etc.), but by ions – molecules with electric charges. Even non distiled water contain enough ions to be conductive. Lets go through several chemical effects of electricity. Electrolysis Electrolysis is a decomposition of liquid compound by passing electric current through liquid called electrolyte(salt water, copper sulphate, sulphuric acid). Electrolysis is used very widely in industry like electroplating of metals, refining of copper and extraction of aluminum from ore. To make electrolysis happen there are two conductors used cathode(-) and anode(-).  

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