Internationally, Isabellenhütte belongs to the leading manufacturers of low-impedance and high precision resistors. Regardless whether of simple design or heavily-loadable power resistors: our series of products satisfy the highest demands. In 1987 we were the first in the world to produce the SMD-mOhm current-measuring shunt. Up until today we set standards in this technology.

Small temperature coefficient, low thermoelectric voltage, high long-term stability, low inductance and high (pulse-)loadability: these are the essential requirements on precision resistors for current sensing. Some of the features can be determined through resistance materials, other factors can be influenced by the design.

We distinguish two production technologies: ISA-PLAN® (foil resistors in etching technology) and ISA-WELD® (electron-beam-welded Cu-Manganin®-Cu strips).

Using etching technology, the resistance elements are manufactured from foils of the precision resistance alloys (Manganin®, Zeranin® and Isaohm®), that are mounted electrically insulated on a good heat-conducting metal substrate. The planar structures permit low-inductance design forms and very low thermal internal resistances. An optimized current-density distribution avoids the danger of Hot Spots.

Besides the conventional two and four-wire current-measuring resistors, presently five SMD product families are available. They offer a variety of possible uses, among others, in the fields automotive, power electronics, motive power engineering, energy measurement and medicine technology.

 

The resistors of the patented ISA-WELD® process consist of solid electron-beam-welded composite material made from copper and one of our resistance alloy. It can be adapted to almost any optional form or application using stamping and bending techniques and therefore enables a high degree of design flexibility. The so-called SMD shunts are used in high-current applications of the automobile industry, battery charging technology, motive power engineering and in electronic energy meters.

Both technologies complement one another and enables the industrial production of high precision resistors in the value range of 5 µOhm to 100 Ohm. The planar structure of the precision resistors permits a simple realization of the four-wire connection technique.

Our high precision resistors guarantee: