New shunt resistors developed for products with higher rated power

This rise in demand has been fuelled by increasing computerisation in the automotive and industrial markets, along with the rapidly expanding current control application sector and the trend towards high-current circuit designs. In response, Farnell element14 now stocks Rohm's PSR Series shunt resistor which is available in the ultra-low resistance range from 0.2mohm to 3mohm and provides high rated power (4W, 5W), making it ideal for current detection in large-current applications. Rohm relies on special techniques to satisfy high power requirements and ensure high measurement accuracy even in the ultra-low-ohmic (0.2mohm) region, which requires the ability to bond copper electrodes without variations. This is achieved through original precision welding technology to join the resistive metal to thick copper electrodes, achieving high heat capacity with excellent thermal dissipation characteristics. This increases power-handling capability (5W class) while improving productivity. Since the temperature coefficient of resistance in metals increases as the resistance value decreases, ROHM uses a high-performance alloy material for the resistive metal, ensuring a superior temperature coefficient of resistance even at ultra-low resistances, says the company. Typical applications for the PSR series include Inverters, Li-ion battery maintenance and charging, DC brush motors, DC-DC conversion and AC/DC conversion.