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Director, Global Marketing Communications,
MALVERN, Pa. — March 11, 2014 — Vishay Precision Group, Inc. (NYSE: VPG) today announced that its Vishay Foil Resistors brand (VFR) has released a new video that demonstrates the advantages of using Bulk Metal® Foil current sense resistors in lithium ion (Li-ion) battery charge-control circuitry. The video compares the stability of Bulk Metal Foil with thin film and metal strip technologies when exposed to extreme temperatures.
Li-ion battery chargers are complex and challenging circuits. They require accurate current and voltage monitoring to avoid undercharging — resulting in reduced capacity — or overcharging, which can lead to catastrophic failure. Ultimately, the circuit's performance is determined by the accuracy and stability of its current sense resistor. In extreme environments, the stability of the resistor is even more critical due to factors such as TCR, power coefficient, and thermal EMF.
To illustrate this, the video released today utilizes an ultra-precise resistance bridge to measure and monitor the stability of thin film, metal strip, and Bulk Metal Foil 50 mΩ, 1625 current sense resistors when subjected to temperatures of +125 °C and -40 °C. Under these conditions, the thin film and metal strip devices demonstrate a great sensitivity to heat and cold, resulting in unstable performance. The Bulk Metal Foil VCS1625Z resistor, however, is highly stable with very little change in resistance.
“When working with Li-ion batteries in high-reliability applications where people's lives are at stake or battery packs are being utilized in remote locations, there is no room for error,” said Yuval Hernik, senior director of application engineering for VFR. “The relative stability among the technologies shown in this video applies even to lesser extremes of temperature. The poor TCR and thermal EMF characteristics of thin film and metal strip devices could easily put the battery they are monitoring at risk of rupture or fire. Vishay Foil Bulk Metal Foil current sense resistors, however, achieve the necessary stability and accuracy for charge-control circuitry, and play a key role in ensuring Li-ion battery safety.”
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
About VPG Foil Resistors
VPG Foil Resistors, a part of Vishay Precision Group (VPG), produces the most precise and stable resistors available. Distinguished by the premier brands Vishay Foil Resistors, Powertron, and Alpha Electronics, the VPG Foil Resistors portfolio includes 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. These devices 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. To learn more, visit www.vishayfoilresistors.com
Bulk Metal is a registered trademark of Vishay Precision Group, Inc.