Researchers at the Korea Advanced Institute of Science and Technology (KAIST) have developed a wireless power system offering inductive power transfer of up to 5 m between the transmitter and receiver coils (see video demo at 1:04, below). Based on compact magnetic dipole type coils with cores (see image below), the "Dipole Coil Resonant System (DCRS)" measures 3 m x 10 cm x 20 cm and was able to deliver a maximum output power of 1,403 W at 3 m, 471 W at 4 m, and 209 W at 5 m. Power efficiency was 36.9% at 3 m, 18.7% at 4 m, and 9.2% at 5 m. See the research paper: "Innovative 5m-off-distance Inductive Power Transfer Systems With Optimally Shaped Dipole Coils."
The overall configuration of the Dipole Coil Resonant System, showing primary and secondary coils.
Researchers at George Washington University's Micro-propulsion and Nanotechnology Laboratory have combined graphene flakes with carbon nanotubes using a simple manufacturing approach to create a low-cost, high-performance paper-based supercapacitor. The device's specific capacitance is claimed at 100 F/g -- on par with that of some other types of ultracapacitors, but able to be achieved with cost advantages, according to the researchers. For details, see the research paper: "Paper-Based Ultracapacitors With Carbon Nanotubes-Graphene Composites."
In product news, Linear Technology has introduced a high-efficiency 17-V, 2-A synchronous monolithic step-down regulator. The LTC3624 offers a Vout range down to 0.6 V, a quiescent current of 3.5 µ, fixed frequency (1MHz/2.25MHz), and 95% max efficiency.
A new current-sensing solution for battery management systems from ams requires no shunt resistor. Based on an AS8510 data-acquisition front end, the AS8510 reference design measures current to an accuracy of ±1% by monitoring the voltage drop across a copper track on the PCB.
Murata Power Solutions has announced new 2-W high-isolation dual-output DC/DC converters suitable for "high/low"-side IGBT drive applications. Packaged in an industry-standard SIP format and achieving a 0.81-W/cm3 power density, the MGJ2 series comprises 12 models with nominal 5-, 12-, 15- or 24-VDC inputs and +15/-5-, +15/-8.7-, or +20/-5-VDC outputs.
International Rectifier has expanded its StrongIRFET power MOSFET portfolio with the addition of 14 60-V(BR)DSS devices. Aimed at a wide variety of industrial applications, the MOSFETs feature ultra-low RDS(on), very high current-carrying capability, a soft body diode, and a 3-V typical threshold voltage.
Behlman Electronics has introduced an AC power source/frequency converter/inverter it designed that can simulate any worldwide utility, as well as aircraft and shipboard power. The microprocessor-controlled Model PF1352 delivers 1350 VA of regulated AC power in a 3.5"-high rack-mount-convertible benchtop unit.
Vishay Intertechnology has introduced eight new FRED Pt ultrafast recovery rectifiers in low-profile SlimSMA packages. The new VS-2EJH0xxM3/VS-3EJH0xxM3 devices offer reverse voltages of 100 and 200 V, reverse recovery time down to 25 ns, and typical forward voltage drop of 0.74 and 0.72 V for the 2- and 3-A devices, respectively.
Last, Cornell Dubilier Electronics has announced the availability of a new capacitor series for 3-phase AC power harmonic filtering. The Type PFCH capacitors have ratings ranging from 0.5 KVAR to 17.5 KVAR at 240 Vac, 0.5 to 30 KVAR at 480 Vac, and 1 KVAR to 25 KVAR at 600 Vac.