 Alpha-Core Introduces new Line of Amorphous Magnetic C-Cores for High Frequency Electronics Applications
Alpha-Core, a division of Bridgeport Magnetics Group, Inc., has introduced a new line of Magnetic Amorphous C-Cores. With its improved magnetic properties, Amorphous Cores offer several advantages over cores made of Silicon Steel, Ferrite and Powdered Iron such as almost 50 percent size and weight reduction due to its much higher saturation induction. Its ultra-thin lamination thickness of one mil (25 um) results in much lower core losses. Amorphous Cores can operate at higher frequencies at the same flux level while conventional steel cores as the frequency increases must operate at lower flux densities and to compensate the designer must use larger size cores. Another advantage is a wide operating temperature range from -55°C to 130°C.
The properties of Amorphous C-cores make them highly suitable for transformers in Switching Mode Power Supplies (SMPS) operating at frequencies from 400 Hz to 20 KHz and inverters in Welding Equipment, Wind Turbines and Solar Panels. Other uses that benefit from Amorphous cores include output filter chokes in large SMPS, Power Factor Correction Chokes in UPS systems and High Power Lamp Ballasts. The amorphous magnetic alloy is made in a process in which molten metal is cast into thin ribbons.
Alpha-Core will stock Amorphous Cores with power ratings (Wa cm2) from 3.3 to 966.0. List prices start at $5.12 for the smallest size.
 Low-Noise Aerospace-Qualified Magnetometer
Bartington Instruments has recently been taking enquiries from customers about the Mag629 three-axis magnetometer. Users of this magnetometer have traditionally been from the defense sector, perhaps not surprisingly since the Mag629 complies with a number of Military Standards, including those related to temperature and vibration.
However, the 629’s robustness means it is capable of operating in particularly harsh environments and its two-piece construction enables its use in an extremely wide range of applications. For example, the Mag629 is well suited for airframe compensation on standard aircraft but can just as easily be mounted on land or sea-based vehicles.
The three sensor axes are arranged to have a common point of intersection (concurrent), clearly defining the “center of measurement” of the magnetic field being examined. The tough and compact sensor head is normally separated from the electronics module by a one meter cable, but this can be modified, within certain parameters, to suit the customer’s requirements.
The Mag629 features low noise (<8pTrms/_Hz @ 1Hz), bandwidth of 1.1 kHz, ±75 μT full scale range, concurrent sensing axes, -55°C to 55°C continuous operating temperature range, two part construction, operates from a 28 V supply, and is tested to MIL-STD-202G, MIL-STD-810C, MIL-STD-810F and many others.
 Quantum Design Unveils New Physical Property
Quantum Design has unveiled a new addition to its Physical Property Measurement System (PPMS) product line.
The PPMS DynaCool meets Quantum Design’s highest standards of cryogenic and magnetic sensitivity, automated system functionality and expandable customization. This cryo-free system uses a single two-stage Pulse Tube cooler to cool both the superconducting magnet and the temperature control system, providing a low vibration environment for sample measurements. In addition, it employs a unique He-based gas flow control system that provides rapid temperature cycling and accurate temperature control. The PPMS DynaCool also comes equipped with an integrated Cryopump used to pump out the sample space to a vacuum of < 10-4 Torr.
Boasting a standard temperature range of 400 K to 1.9 K and magnetic fields up to 14T, the PPMS DynaCool allows for a wide range of measurement options such as heat capacity, thermal transport and electrical transport. Additional measurement options include a vibrating sample magnetometer (VSM), VSM oven, dilution refrigerator and 3He refrigerator.
 High Sensitivity Telecoils for Hearing Aid Compatible with Mobile Phones
PREMO enlarges its telecoil family with the new TP0602 series, a reliable and sensitive coil for applications in hearing aids.
The TP0602 is wound with thin copper wires less than 25 micron (up to 0.012 mm diameter) and inductance values between 40 and 170 mH. This telecoil achieves a high sensitivity to magnetic field in 1 kHz (operation frequency in this kind of devices). The ferrite core material provide a stable performance in a wide range of temperatures (-10ºC to 40ºC).
Its surface mounting device (SMD) configuration allows an easy integration in an automatic printed circuit board assembly process, avoiding handling of the piece that could damage winding wire of the piece. That makes this piece different regarding main existing telecoils, commonly with a pig-tail wires or “thru-hole” configuration (that requires an additional wave soldering process).
These components, included in most of existing hearing aid devices, work as a magnetic field sensor, turning the magnetic field into electric voltage as a standard microphone does with the acoustic energy. This allows the hearing handicapped people to receive the signal from a magnetic inductive loop located in public buildings and transports.
Telecoils are particularly useful for telephone communication because they permit the volume control of a hearing aid to be turned up without creating feedback, and background noise can be reduced especially when using cell phones in noisy places. The user can change the phone coil in manual or automatic way to create a magnetic field as intensive as to transmit the signal to hearing aid.
A hearing aid is compatible with mobile phones when meets the FCC’s technical standard for hearing aid compatibility and must have a telecoil. Since February 18, 2008, mobile phone manufacturers and service providers had to ensure that at least 50 percent of all handsets marketed in the US meet the requirements of ANSI C63.19:2006.
The quality and reliability of these telecoils has been evaluated positively for the main hearing aid manufacturers. PREMO´s telecoil product range offer different sizes to allow its inclusion in most hearing aids models in the market. These series, TC0502, TP0602, TC0902 and TC1102 are available also with “custom” electrics characters according to customer needs.
New Tools Boost Performance of Superconducting Magnet Simulator
Cobham Technical Services has delivered new modeling tools that extend the accuracy and speed of multi-physics finite element simulation used to develop superconducting magnets. The tools exploit advanced finite element meshing algorithms and other facilities to boost simulation accuracy while simultaneously halving simulation times.
The advanced finite element meshing algorithms and other tools were developed as part of the company's role in the UK's IMPDAHMA project. IMPDAHMA (Integrated Modeling Package for Designing Advanced HTS Materials Applications) - partially funded by the UK government's Technology Strategy Board - was led by superconducting magnet supplier Oxford Instruments whose aim was to obtain an integrated design and modeling environment.
Three organizations collaborated in IMPDAHMA: Oxford Instruments NanoScience, Cobham Technical Services and The Institute of Cryogenics at Southampton University. As well as leading the project, Oxford Instruments was responsible for manufacturing and testing sample magnets that included high temperature superconductor (HTS) materials and measuring material properties of composites. Southampton’s role was to obtain very precise measurements of the constituent materials at cryogenic temperatures – a crucial element to getting accurate simulation results – and also to validate the environment against Oxford Instruments’ tests. Cobham’s task was to develop its existing low temperature superconductor (LTS) simulation tools to include both LTS and HTS materials, while improving performance and accuracy.
The tools provide a direct link from the advanced superconducting magnet design and material know-how represented in Oxford Instruments' Magnet Design Database to the superconducting 'quench' solver in Cobham Technical Services' multi-physics Opera tool chain for the modeling, simulation, analysis and optimization of electromagnetic related equipment.
Understanding the quenching process - a rapid, highly non-linear and potentially dangerous change of state from superconducting to resistive mode - is critical for this design area because superconducting magnets operate close to their critical current for reasons of performance and cost. Accurate quench simulation depends on a complete specification of the wires, coils, materials and protection circuits used in the magnetic system.
Cobham Technical Services' work during the project has resulted in three new capabilities for Oxford Instruments. The most fundamental advance is in the finite element meshing algorithms that divide a 3D computer design model of a magnet down into smaller connected elements to allow numerical solution. Models can now be meshed using a 'mosaic' mixture of prism, hexahedral and pyramidal element shapes (as well as the tetrahedral elements that were available previously), to enhance the accuracy of the simulation solution. This mosaic meshing also improves the speed of the subsequent coupled multi-physics transient thermal and eddy current simulations. Assembling the non-linear thermal equations at each time step is much more efficient, and eddy current skin effect in conducting formers can be captured with fewer elements. The transient thermal and electromagnetic simulations were also configured so that they can run in parallel on different processors to further improve speed of execution.
Cobham Technical Services also enhanced the capability of Opera’s electrical circuit modeling, including a brand new graphical interface, which describes the power, drive and protection circuitry that is essential to superconducting magnet operation (and current dissipation when a magnet goes into quench). And the company provided a direct link to Oxford Instruments' materials database, which represents the complex non-linear properties of superconducting materials. A new materials database structure that will be integrated into a future version of Opera was developed to hold the wealth of materials information created in the project. However, this database is also extendable to hold materials data for many other electromagnetic design applications.
The new Integrated Modeling Environment that has resulted from the IMPDAHMA work has been validated by The Institute of Cryogenics. Oxford Instruments conducted tests on two high-field NMR (nuclear magnetic resonance) systems used for validation. A 20 Tesla magnet with LTS coils was used initially, and an LTS magnet with additional HTS coil inserts (potentially capable of achieving a field of up to 25 Tesla) was used as new software tools and materials data became available. The tests showed very encouraging agreement between the real-world measurements and calculated values.
The new version of the Opera package that will incorporate most of these new resources will be released before the end of 2010.
New Lines of Common Mode Toroid Power Inductors/Chokes
Prem Magnetics, Inc. has introduced several series of common-mode chokes for reducing unwanted common-mode noise signals on a power line. Comprising a total of 128 parts utilizing seven different mounting packages, the SPCM series covers inductance values ranging from 65.0 uHy to 120 mHy and current values ranging from 0.3 ADC to 30 Arms.
All of these common mode chokes utilize toroidal core construction that offers a small size and reduced EMI. Mounting styles are printed circuit board mount incorporating either through-hole or surface mount technology (SMT). Component orientation is configured for reduced height or reduced board real estate. Many of these chokes incorporate a winding separation spacer that provides 1 to 3 mm creepage distance for safety agency compliance, and all units use UL94V0 materials.
Package dimensions for these series range from 14.5 mm square by 10.8 mm Ht. to 40 mm by 40 mm by 19 mm Ht. Pricing ranges from $1.39 to $5.67 in production quantities.
Piezo Ceramics for Medical Applications
A new brochure from piezo specialist PI on medical applications of piezo ceramic actuators and components is available for download at:
http://www.pi-medical.net/Motion_Control_Medical_Design_Catalog.pdf
 Piezo motors and actuators have several advantages over classical motion control components. Examples are:
- Sterile / high bake-out temperatures
- No lubricants required,
- Non-magnetic principle (MRI …)
- Vacuum compatible
- Smaller, higher force
- Faster response
- Direct linear motion w/o conversion losses.
Application Examples
- Piezo ceramics for pumps, nebulizers and atomizers
- Piezo motors for micro liquid dispensing
- Non-Magnetic piezo motors for Imaging / OCT, MRI
- Scanning stages for bio-research microscopy
- Hexapod robots for computer aided surgery
|
Download a PDF Copy of the 
