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400-803-9333Wirewound power resistors are usually rated with respect to continuous power, which can be insufficient for e-mobility applications. A typical application is the pre- and discharge of large capacitors, often referred to as soft start. In this case the pulse-handling capability of the resistor is also very important. This capability can be determined over a large range of pulse durations by combining theoretical basics with finite element simulations of the respective thermal performance. The results can be generalized so that...
Date：2019-11-19 [More+]Global provider of engineered electronics for performance critical applications, Microhm Electronics, has announced the heatsink specifically designed to optimise the thermal performance of its NLR series and MVR series power resistors. Providing a combination of high surface area, cooling performance, compact dimensions and light weight, the PCB mounting heatsink is suitable for use in power supplies, power amplifiers, motor drives and inrush current control applications requiring resistors operating in the 20-100W range. H...
Date：2019-11-13 [More+]A device to measure electric current is called an ammeter. Most modern ammeters measure the voltage drop over a precision resistor with a known resistance. The current flow is calculated by using Ohms law: Ohms Law I=V/R Most ammeters have an inbuilt resistor to measure the current. However, when the current is too high for the ammeter, a different setup is required. The solution is to place the ammeter in parallel with an accurate shunt resistor. Another term that is sometimes used for this type of resistor is ammeter shunt...
Date：2019-11-06 [More+]Ultra-precision, high-side current sensing is crucial in applications where the correct amount of current entering or leaving the battery needs to be measured to a very high degree of precision. A layout designer and design engineer need to take to measure ultra-high precision voltage drop across a shunt resistor. These measurements are enhanced utilizing the proven Kelvin sensing methods with a four-terminal sense resistor. Microhm Electronics MVR2321-4, MVR3825-4 and MVR4618-4 are most used 4-termial Kelvin resistors. Ultra...
Date：2019-11-06 [More+]When an electrical current passes through a resistor due to the presence of a voltage across it, electrical energy is lost by the resistor in the form of heat and the greater this current flow the hotter the resistor will get. This is known as the Resistor Power Rating. Resistors are rated by the value of their resistance and the electrical power given in watts, (W) that they can safely dissipate based mainly upon their size. Every resistor has a maximum power rating which is determined by its physical size as generally, the ...
Date：2019-11-05 [More+]In recent years, renewable energy options have become much more efficient and feasible. This has led to a large adoption of these applications, an especially poignant point in the face of current environmental issues. However, just like all other power generation methods these applications require resistors. Microhm Electronics provide various power resistors for this application, such as TO-220 type, TO-247 type, NUAL series, MMS series and more. With the recent news that E.ON UK plans to power more than 3.3 million custome...
Date：2019-11-04 [More+]Current sensing is a critical function in electronic systems but comes with complexities that are often underestimated. This part we discuss current sense resistors. MPR series, MVR series and MMS series form Microhm Electronics are popular current sense resistors. Accurately measuring current flow is not nearly as easy as measuring voltage and is even more difficult when trying to measure the current flowing through a load connected to relatively high-power supply voltages. Current sense resistors, also called shunt resistor...
Date：2019-11-04 [More+]Current sense resistors are very low value resistors used to measure the current flowing through it. Microhm Electronics MVR2321-4, MPR series, MMS series are most often used current sense resistor. The current through the resistor is represented by the voltage across the resistor, so by applying I = V/R as set down by the famous school teacher Georg Simon Ohm, the current is proportional to the voltage across the resistor. This simple introduction to the topic is the beating heart of the rest of this current article. The to...
Date：2019-11-01 [More+]