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MALVERN, PENNSYLVANIA — Nov. 15, 2012 — Vishay Precision Group, Inc. (NYSE: VPG) today announced that its Vishay Foil Resistors brand (VFR) has released a new video that compares the stability and accuracy of three different current sense precision resistor technologies used in solar panels: thick film, metal band, and next-generation Bulk Metal® Z-Foil. The short video demonstrates how an increase in ambient temperature results in a change in accuracy and stability in thick film and metal band resistors; but has no effect on the Z-Foil resistor.
Using a scaled-down model of a typical solar cell energy system, the video introduced today highlights the accuracy and stability of VCS1625Z current sense resistors under increasing ambient temperatures. In the demonstration, 50 mΩ thick film, metal band, and VCS1625Z current sense resistors of the same size are used to monitor the charging current from the solar cell to a battery.
After the initial output is recorded, the ambient temperature is increased using a controlled heat gun. With an increase in ambient temperature, the thick film and metal band devices lose their stability and accuracy. The VCS1625Z resistor, however, continues to provide a precise reading of the output current regardless of the heat applied. Furthermore, the resistor’s stability won’t change due to self heating when carrying increased current loads.
“One of the most important aspects of designing and using alternative energy sources like solar cells is accurately and consistently measuring the current flow using a real current sense precision resistor with four terminals,” said Yuval Hernik, senior director of application engineering for Vishay Foil Resistors. “A very real concern in the accuracy of this measurement is the effect of variant ambient temperatures on resistors in different real-world environments.
“For alternative energy equipment in remote locations, it can be very expensive to access, repair, and calibrate systems. Therefore, applications such as power supplies, calibration units, and power monitors in wind and solar energy equipment require component technologies with unquestioned accuracy, stability, and reliability to minimize cost and improve efficiency. Vishay Foil Resistors’ current sense devices have a clear advantage over all other technologies in these applications.”
About VPG Foil Resistors
Distinguished by the premier brands Vishay Foil Resistors, Powertron, and Alpha Electronics, VPG Foil Resistors is part of Vishay Precision Group (VPG), producing the most precise and stable resistors available. The portfolio comprises products in a variety of resistor and package configurations to meet the needs of a wide range of applications: discrete resistors and resistor networks in surface mount and through-hole (fixed-lead) configurations; customized chip resistor networks; precision trimming potentiometers; and discrete chips for use in hybrid circuits. The foil resistors and current sensors are used in applications requiring a high degree of precision and stability, such as in medical testing equipment, semiconductor equipment, precision measuring instruments, aerospace, and military applications.
About Vishay Precision Group
Vishay Precision Group (VPG) is an internationally recognized designer, manufacturer and marketer of: components based on its resistive foil technology; sensors; and sensor-based systems specializing in the growing markets of stress, force, weight, pressure, and current measurements. VPG is a market leader of Foil Technology Products, providing ongoing technology innovations in precision foil resistors and foil strain gages, which are the foundation of the Company’s Force Sensors Products and its Weighing and Control Systems. The product portfolio consists of a variety of well-established brand names recognized for precision and quality in the marketplace. To learn more, visit VPG at www.vishaypg.com