These current sense resistors are predominantly used in automotive application in the DC/DC convertor output block and in battery management. The basic circuitry followed is that these low ohms resistors are connected in series with the load, and the potential difference between both terminals are measured by an IC to determine the quantum of current flow. The performance of IC’s available today has made great strides which enable them to measure current more accurately by being able to read ever diminishing potential differences.
The result of this is that by using ultra low resistance values it is possible to detect even large currents in excess 160 AMP, with lower power consumption as compared to devices being used at present. Using the older thick film technology, these low ohms resistors are made by screen printing the resistive element and electrodes on an alumina substrate and generally speaking these thick film resistors which are available today have resistance range in tens of milliohms. The electron beam welded metal band resistors have a very rugged construction where the different resistance alloys selected are welded to the copper electrodes. The very nature of the construction of these resistors contributes to excellent heat dissipation as compared to the thick film variety.
Using this technique it is possible to made devices with resistance range of several milliohms which mean a much lower resistance value as compared to thick film devices and with the characteristic of superior heat dissipation as compared to the thick film devices, hence lending itself to providing a smaller & more reliable device. Hence, the metal strip resistors offer higher power and very precise temperature co-efficient of resistance as compared to thick film devices.
Further since these electron Beam welded metal band resistors can be made having resistance value much lower than thick film devices, they have the added advantage over thick film devices by being able to exploit the property of the latest IC’s which can now measure even the smaller potential differences.
At HTR, being an ISO/TS 16949:2009 company, we are committed to offering our automotive customers the full range of resistive devices using the latest electron beam technology to contribute to the quest of enhanced detection accuracy, reduction in the size of the devices and in conserving power consumption.
To this end we offer the following series.