Latest resistor family offers powerful current measurement in the smallest of spaces

Isabellenhütte will exhibit its latest WAx resistor family at the PCIM. The family's resistance values are achievable in small sizes from 1mOhm to 0.5mOhm.

With the latest resistor series, the company is closing a gap in its portfolio for very low resistance values in small sizes. In relation to their small size, the resistors in the series measure relatively high currents and, therefore, offer a very good cost-benefit ratio. Resistance values from 2mOhm were already possible with the last FMx series. The new WAK (size 1206) and WAF (size 1213) resistors can also offer resistance values of 1mOhm and 0.5 mOhm. The WAF with a resistance value of 0.75mOhm is also currently under development.

These low-resistance values in the smallest sizes are made possible by the production process of roll cladding, which the company has used here for the first time. In this process, a copper strip and a strip made from one of the company's own resistance alloys, Manganin or Zeranin, are rolled together to form a mechanically stable duo strip. The final component geometry is punched out of the duo strip – the WAF is very small, measuring just 3.1mm x 3.3mm; the WAK is only half the size. Thanks to the resistor alloys used, the resistors benefit from high long-term stability, a very good temperature coefficient and a high load capacity with low inductance (<0.5nH). All components are AEC-Q200 qualified and are also provided in these small sizes with an initial tolerance of ±1%; i.e. each component produced is individually trimmed at the company. To optimise the technical properties of the components, we recommend using the layout shown in the datasheet.

These resistors are already in series production and are ideal for a wide range of applications. Example applications with limited space, where a low weight of all components is also required, are drives for e-bikes or e-scooters and drones, for example for land surveying, as well as BLDC motors, e.g. in white goods applications.

See the resistor family at PCIM from 11 to 13 June 2024.