LEM's Sentinel 3+ is a battery-monitoring transducer that measures
the voltage, temperature and impedance of cells and complete batteries in
uninterruptible power supply (UPS) installations of all sizes up to mega-watt
back-up power supplies for data centers and hospitals. Sentinel 3+ reports its
measurements - on valve-regulated lead-acid (VRLA), gel or flooded stationary
batteries - to supervisory systems over a dedicated communications bus, and
offers a unique capability to assess the true state-of-health of UPS batteries
while they are in service. Sentinel 3+ gives complete confidence that battery
arrays will deliver their rated power when called on to do so, and identifies
weak and failing cells without the need to remove them from service for cycling
Technology developments such
as the availability of fast insulated-gate bipolar transistors (IGBTs) reduce
costs by eliminating transformers from their circuit configurations. The
battery packs that the Sentinel product monitors are operated in a floating
voltage mode: the battery is subjected to higher ripple currents, and the
monitoring circuitry must handle high common-mode voltages, with superimposed
high-amplitude, fast transients.
LEM's Sentinel 3+ has upgraded
algorithms to address more challenging measurement environments and improved EMC
immunity and enhanced robustness. Sentinel 3+ delivers voltage measurements
over a range of 0.9 to 16 V with an accuracy of +/-0.5 percent; impedance
measurement from 0.05 to 250 mO with repeatability of +/-2 percent.
Sentinel 3+ features Common Mode Transient Immunity up to 20 kV/µsec with a
common-mode voltage level of +/-600 V, and a transient repetition rate of 20
During a teardown of the iPad Air and Microsoft Surface Pro 3 at the Medical Design & Manufacturing Show in Schaumburg, Ill., an engineer showed this "inflammatory" video about the dangers of maliciously mishandling lithium-ion batteries.
The Window Watcher stops the burglar before he does damage or enters the house. House alarm service companies set off alarms and call the service only after the burglar has damaged and entered the house.
If you’re designing a handheld device or industrial machine that will employ a user interface, then you’ll want to check out the upcoming Design News Continuing Education Center course, "Engineering Principles Behind Advanced User Interface Technologies.”
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.