- Buyers Guide
Vishay Precision Group Inc. announced that its Vishay Foil Resistors (VFR) brand 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.
Link to video: http://www.vishaypg.com/foil-resistors/videos/?video=34
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."
Further information about Vishay Foil Resistors products is available at www.vishayfoilresistors.com.
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