Contactless potentiometers

1999/03/21 Kortabarria Olabarria, Beñardo - Elhuyar Zientzia

• Elektronika

The potentiometers are an instrument that allows to increase or decrease the volume of radio, musical apparatus or television, modify the speed of the agitator or fan and, in general, modify the intensity of a magnitude. Its use is enormous and around 4,000 million are manufactured annually worldwide. They operate by continuously modifying the electrical voltage that basically feeds a circuit. Most potentiometers have a resistance and a cursor that slides over it and wear out by friction.

A non-electric contact potentiometer has recently been presented at the Institute of Materials Sciences of Spain. The electrical voltage variation is magnetically modulated using magnetoresistant manganese materials. These materials modify their ohmic resistance when they are inside a small magnetic field.

Researchers have presented a prototype and industrial development has now begun. The objective is the industrial manufacture of magnetic potentiometers, as they will be much cheaper than traditional ohmic potentiometers. Together with the researchers of the aforementioned Institute of Materials Sciences, the Navarra company of Electronic Components (Nacesa), the CEIT technology center of Gipuzkoa and the University of the Basque Country participated in the project.