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The range and complexity of electrical equipment has increased dramatically in recent years. An unwanted consequence of this rise is the creation of harmonic currents, which can cause voltage distortion and quality problems. Also known as damping resistors, harmonic filters reduce distortions in power systems, which can be produced by nonlinear loads such as arc furnaces and switch-mode power supply (SMPS). Harmonics can have adverse effects on the power supply network. If the nonlinear loads produce unwanted harmonics, they ...
Date：2019-09-04 [More+]
There are a vast array of power supplies on the market, and the variety of resistor applications in those designs broaden the selection dramatically. Engineers from power supplier factorys often consult high voltage resistors, like HPMRY, PMRY, EE series, MPF series from Microhm Electronics. So, for the purpose of this article, power supplies will be referred to as devices that have fixed DC outputs up to several kV. Whatever the application, power supply designers must be aware of specific regulations on safety or the enviro...
Date：2019-09-04 [More+]
Metal film leaded resistors are almost the definitive standard used these days. Cost, reliability, and availability of close tolerance product means that they are almost universally used for general purpose leaded resistor, HPMRY series, PMRY series, EE series, NLT series from Microhm Electronics are your best options when choosing metail film resistors. Another advantage of metal film resistors is that they generate low levels of noise as a result of their construction and technology. Offering a high tolerance as well as pro...
Date：2019-09-02 [More+]
Current flows through circuits when a voltage is applied to them. One way to limit this flow is with a resistor. Precision resistors, power resistors and shunt resistors are ready in Microhm Electronics for engineers option. How well resistors oppose current flow depends on their resistance. Ordinary resistors obey Ohms Law, where the voltage, V, is equal to the current, I, multiplied by the resistance, R. Resistors can be tested in and out of circuit by measuring their resistance. They may be tested in circuit by measuring t...
Date：2019-08-30 [More+]
Besides the corresponding precise calibration measuring devices also precise calibration resistors are required for the calibration of testers. These calibration resistors, like Microhm Electronics MVR2321-4, MVR3825-4, MVR4618-4 and NSR, serve to let certain test currents flow at various test methods and test voltages. In doing so it is tested to what extent the measured voltage and current values indicated by the tester to be calibrated correspond to the measured values of an external measuring device. Minor deviations with...
Date：2019-08-27 [More+]
The function of resistors is to oppose the flow of electric current in a circuit. Therefore their primary parameter is the resistance value. The manufacturing tolerance must be adequately chosen for each specific application. The ultimate resistance value may deviate from the specification because of many reasons. One is the temperature coefficient of resistance, or TCR, which is often specified for precision applications. Stability defines the long term variations of the resistance. After a long duration of electric load, th...
Date：2019-08-26 [More+]
Power resistors are designed to withstand and dissipate large amounts of power. In general they have apower ratingof at least 5 Watt. They are made from materials with a high thermal conductivity, allowing efficient cooling. They are often designed to be coupled with heat sinks to be able to dissipate the high amount of power. NLR series and MVR series from Microhm Electronics are very popular precision power resistors with heatsink, Nual series is a traditional metal-clad power resistor. Some might even need forced air or li...
Date：2019-08-24 [More+]
The ability to measure low values to tight tolerances is a concern to both the manufacturer and the user. Microhm Electronics low ohm resistors with tight tolerance covering shunt resistosrs, metal foil resistors, metal film resistors and more. The problem is compounded in the cases of high current shunts where the self-heating will cause the in-service resistance value to be different than that obtained with low current level measuring equipment. Therefore, the measurement conditions must be defined at the time of specificat...
Date：2019-08-22 [More+]
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