Our precision and power resistors primarily differ in terms of their manufacturing technologies. ISA-PLAN® (etched foil resistors) and ISA-WELD® (electron beam welded composite material of Cu-MANGANIN®-Cu). These two technologies enable us to meet the most demanding applications: high long term stability, continuous load capacity as well as high pulse power rating, minimized dissipated energy in high current metering, low inductance- and TC-values and low thermoelectric voltage against copper. Both technologies complement each other which results in a large portfolio of precision resistors in the value range of 2 µOhm to 470 Ohm.
Our precision resistors guarantee
- High permanent power in small sized construction
- Extremely low TC-values
- Very good long term stability
- Low ohmic resistor values start at 2 µOhm
- High continuous load and pulse load capability
- Standard delivery meeting the closest tolerances
- Thermoelectric voltage against copper eliminated as far as possible
ISA-WELD® - TECHNOLOGY
The resistors of the patented ISA-WELD®-method consist of massive, electron beam welded composite material of copper and one of our resistor alloys (MANGANIN®, ZERANIN®, ISAOHM®, Aluchrom). This composite material can be adapted to almost any form by punching and bending and enables highest flexibility in the field of application design. These shunts are used in high current applications of the automobile industry, industrial- and power electronics, battery charging, drive technologies and for electronic energy metering.
The resistors are punched out of three longitudinally welded strips in which the procedure is very flexible. Thickness and widths of the strips are as variable as the resistor materials used. The almost free shaping capability in the punching, bending and stamping process leads to increasing design solution options for the application in question.
The composite material is welded continuously at the strip in a vacuum via electron beam and without any additional material. Additionally the strips are cleaned upon machine entry and the flanks are finish machined. By doing this impurities or oxides in the weld can be avoided and physically different materials can be welded cost-effeciently - with zero-defects. A special advantage is the small welding area with about one third of the metal thickness. Due to this the transition occurs abruptly which minimises the influence of the alloy area to the resis-tor value and the electric features of the metering resistor. Your advantage as user: the connection of resistor material and copper during the component assembly on the electrical panel or busbar must not be done by yourself.
The comparatively low leading resistance of the copper connections make sure that the total resistance value is only marginal higher than the actual measuring resistor. The total load is reduced to a minimum by doing this.
Additionally the heat which is generated in the resistor material is dissipated very efficiently in the conterminal copper connection.
Due to an extremely high conductivity the massive copper connections additionally ensures a uniform current density and heat distribution in the resistor. Hot Spots can be avoided this way and a high pulse and permanent load can be achieved.