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

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Oscilloscope Probes Measuring signals with oscilloscopes may be a 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 the discussion to probes 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 circuits, it is important to know their sensitivity to resistive, capacitive, or inductive loading. Incorrectly chosen probes (like high capacitance) can distort the fast-rising signal. Some circuits may not tolerate probes at all (high-speed amplifiers).

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

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

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