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The impact of temperature upon resistor performance is reflected, both internally, in terms of its effects on component operation; and externally, in terms of resistor behavior within the installation environment. Inherent to resistor design is the concept that, as electrical current flows through a resistor, it generates a certain amount of heat. This is a phenomenon known as the Joule effect. The thermal response created by the Joule effect then induces relative mechanical changes, or stresses, within the resistor. These s...
Date：2019-12-04 [More+]
Illustrations of the benefits of low TCR may be found within thousands of successful applications. In this paper, well see how low TCR and high precision resistors benefits below applications. Precision Instrumentation Transmille, a leading UK manufacturer of high-accuracy digital multimeters (DMMs), was seeking a resistor component for a new series of 8.5- and 7.5-digit units. To achieve necessary 8.5-digit accuracy, the specified resistor needed to offer extremely low TCR, high-precision, repeatability, low thermal EMF, lo...
Date：2019-12-03 [More+]
For most electronic circuits the power rating is not a key parameter, since those resistors dissipate low amounts of energy of one watt or less. In power electronics however, the power rating is an important characteristic. Generally speaking hereto is referred when power ratings are one watt or higher. Typical applications include power supplies, dynamic brakes, power conversion circuits, power amplifiers and heaters. Nual series of Microhm are typical dynamic brakes. The nominal power rating is defined for a certain ambien...
Date：2019-12-02 [More+]
In 1952 the IEC (International Electrotechnical Commission) decided to define the resistance and tolerance values into a norm, to ease the mass manufacturing of resistors. These are referred to as preferred values or E-series, and they are published in standard IEC 60063:1963. These standard values are also valid for other components like capacitors, inductors and Zener diodes. The preferred values for resistors were established in 1952, but the concept of the geometric series was already introduced by army engineer Renard in...
Date：2019-12-02 [More+]
The electronics industry has evolved at a remarkable rate over the past two decades. New techniques and advances have helped shrink equipment size and have put pressure on manufacturers of discrete components, such as manufacture resistors, to develop devices that approach the ideal in performance. Naturally, not every engineer needs an entire high-performance package for their circuitry. Resistors with much poorer specifications can be used satisfactorily in many applications, so the question of need is divided into four ba...
Date：2019-11-29 [More+]
Wirewound precision resistors have some important characteristics. First, they can have very tight resistance tolerances. 0.005% is commonly achieved, such as PWP/PWS series of Microhm Electronics. More important, they are stable maintaining their precision over time because they are made with stable materials. Their TCR (Temperature Coefficient of Resistance) is low (10ppm/C) and can be controlled by selecting special wire alloys. In the past, the bulk of the resistor market went to carbon composition products. They are not...
Date：2019-11-29 [More+]
Resistance measurement applications, for example using string pots to measure movement, measuring thermistors/RTDs for temperature, measuring the resistance on test samples, and many more applications, are often mentioned by users. This article involves resistors ultilizing in low resistance measurement. Microhm Electronics MPR series (LFS series), NMS series, MMS series are often seen in low resistance measurement situation. First, lets consider the cables which are connecting the device to be measured to the instrument: If ...
Date：2019-11-28 [More+]
A variable resistor consists of a track that provides the resistance path. The two terminals of the machine are connected to both the ends of the track. The third terminal is associated with a wiper that decides the motion of the track. The motion of the wiper throughout the track helps in increasing and decreasing the resistance. Microhm Electronics NRS series can be made to variable resistor. The track is generally made of a mixture of ceramic and metal or can be made of the carbon as well. As the resistive material is req...
Date：2019-11-26 [More+]
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