Magnetic Tape Analysis "Sees" Tampering in Detail
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This image, produced by the new NIST forensic tape analysis system, clearly reveals an overdubbing. The new recording is visible from the left bottom of the image to about 188 millimeters on the distance counter, the large smudge at 216 mm was made by the erase head, and the original recording is visible starting at about 220 mm. |
The National Institute of Standards and Technology (NIST) has developed an improved version of a real-time magnetic microscopy system that converts evidence of tampering on magnetic audio and video tapes — erasing, overdubbing and other alterations — into images with four times the resolution previously available. This system is much faster than conventional manual analysis and offers theadditional benefit of reduced risk ofcontaminating the tapes with magnetic powder. NIST recently delivered these new capabilities to the Federal Bureau of Investigation (FBI) for validation as a forensic tool.
Earlier versions of this system made images with a resolution of about 400 dots per inch (dpi). The new system uses four times as many magnetic sensors, 256, embedded on a NIST-made silicon chip that serves as a read head in a modified cassette tape deck. The NIST read head operates adjacent to a standard read head, enabling investigators to listen to a tape while simultaneously viewing the magnetic patterns on a computer monitor. Each sensor in the customized read head changes electrical resistance in response to magnetic field patterns detected on the tape. NIST developed the mechanical system for extracting a tape from its housing and transporting it over the read heads, the electronics interface, and software that convert maps of sensor resistance measures into digital images.
The upgrade included quadrupling the image resolution to 1,600 dpi, the capability to scan both video and audiotapes, complete computer control of tape handling and the capability to digitize the audio directly from the acquired image. The software displays the audio magnetic track pattern from the tape to identify tiny features, from over-recording marks to high-intensity signals from gunshots. The system is designed to analyze analog tapes but could be converted to work with digital tapes, according to project leader David Pappas.
The new nanoscale magnetic microscope also has been used experimentally for non-destructive evaluation of integrated circuits. By mapping tiny changes in magnetic fields across an integrated circuit, the device can build up an image of current flow and densities much faster and in greater detail than the single-sensor scanners currently used by the chip industry, says Pappas.
The FBI’s Forensic Audio, Video and Image Analysis Unit receives hundred of audiotapes for analysis annually, representing evidence from crimes such as terrorism, homicide and fraud. The FBI provided partial funding for development of the NIST tape imaging systems.
Vacuumschmelze Supplies Magnet Systems for XFEL Pilot Project 
Vacuumschmelze GmbH & Co. KG (Hanau) is contributing VACODYM magnets and VACOFLUX components to the construction of a free electron laser (FEL) prototype at the DESY research centre in Hamburg. FELs have been built and operated for almost 25 years. Magnetic structures in the FELs in use today have a maximum length of a few meters.
The DESY (German Electron Synchrotron) laboratory in Hamburg is currently the scene of a European project to design a superlative, revolutionary light source incorporating undulator structures several hundred meters in length.
The project called for ultra-high-quality magnets with mechanical tolerances only detectable using specialist measuring devices. VAC's VACODYM magnets and VACOFLUX components met these high standards and were chosen for the prototypes. This February, staff from VAC's Hanau-based Systems Production Division installed the magnet systems in the first prototypes.
The next step will be to "shim" or adjust the completed structure on-site at DESY in Hamburg, where performance of the VAC components will be measured against the project's high quality specifications. The findings and experience gained in the construction of the prototype structures will be incorporated into the design of the finished laser.
Magnetic Gorilla Post Parking Solution
Pacific Cascade's Gorilla Post system can be found holding its ground in the cities of Sacramento, Miami, Houston, Seattle and Portland; outside of hotels, theme parks and convention centers; and on university campuses, office complexes, transportation concourses and more. Enabling parking enforcement of reserved single spaces, the semi-permanent magnetic post system is strong, flexible and can be installed, or removed, by one person in under five seconds.
Weighing eight pounds, the Gorilla Post is easy to carry and place into service. Once in place, it has 380-psi vertical lift resistance making it virtually impossible to remove without the special post-pulling tool. Standing 48-inches high and made of durable polyethylene, the posts are visible from street-level, and return upright even after a 15 mph impact. The secret is its six-inch Neodymium magnetic base and 3/16-inch thin plate that couples to the street or sidewalk, holding the post in place.
"Larger cities are removing existing parking meters and replacing them with multi-space meters. When using multi-space meters, business owners or city employees have no way to 'bag' a parking space, temporarily holding or reserving a spot," explains Craig Myers, national sales manager with Adams Magnetic Products Co. "Pacific Cascade developed a magnetic-based sign that reads, 'Reserved -- Customer Parking Only,' or some other such message. This quickly grew from a standard item to very customized, magnetic assemblies," says Myers.
The product family continues to evolve, said Mark Curtis, president of Pacific Cascade. Adams also helped Curtis adapt his concept to a custom-order granite bollard for the City of Portland. "These stone columns were installed as parking delineators and, if hit, they would be nearly impossible to replace or repair. So, we carefully designed and secured a magnetic base similar to our Gorilla Post bollards, but capable of holding the 13-inch diameter, 30-inch tall stone structures."
"It's been an exciting project and there's even more new products and improvements underway," Myers previews. "After five years, we have established a relationship that goes beyond customer and supplier. We help with materials sourcing and services, just-in-time inventory management, references and referrals, and look forward to seeing each other in-person whenever possible, not just because he's a good client, but because he's a good guy and we glad to be a part of his continued success."
Magnetic Kit Encoders for Brushless DC Motors Offer High-Speed, Accuracy and “Fit and  Forget” Reliability with Compact, End-of-Shaft Mounting
Solid State magnetic rotary encoder kits from Renishaw combine high-speed and accuracy with exceptional compactness and no-wear “fit and forget” reliability. Breakthroughs in simplicity, essentially just a magnet and an AM256 chip, the Renishaw rotary encoders are a suitable fit for end-of-shaft mounting and motor feedback with axial length of 1/8 inch (3 mm) and diameters down to ¾ inch (19 mm). Suitable for demanding high-speed applications, the compact, low-mass, no-wear encoders enable rotational speeds to 60,000 rpm. Robust industrial designs, the kit encoders handle motor stall and overload, high shock and vibration conditions, and wide temperature range from-40°C to continuous operation at 125°C.
The versatile magnetic encoders are available with absolute, incremental and analog outputs in a range of industry standard formats with resolutions from 6 to 12 bit (2.6° to 0.08°). By simple addition of a magnet into the end of the motor shaft and the location of a small PCB module just clear of the shaft, high purity sine and cosine signals are produced at one cycle per turn. Absolute shaft position can then be determined to high resolution for feedback and commutation control.
Highly immune to stray magnetic fields in the motor, the AM256 sensor uses a self-compensating array of Hall effect sensors and analog processing techniques. The large array of Hall sensors, coupled with very accurate conditioning of the signal outputs, ensures high purity signals, accuracy to ±0.3° and resolution to 12 bit (4,096 counts per rev).
Equally smooth control is provided in both motor turn directions, non-contact, no-wear design and high reliability silicon processes yield industry-leading reliability figures even at elevated temperatures.
Weapons Detection Portal 
QUASAR Federal Systems (QFS) recently incorporated its state-of-the-art passive magnetic sensing technology into a portal useful for detecting, and localizing, weapons within a second on persons entering public buildings such as libraries, schools and post offices, in addition to privately owned buildings. QFS’ screening system also scans crowds attending public forums such as sports stadiums, theme parks and theaters. Moreover, the QFS portal is well suited for screening containers carried into buildings and monitoring people walking from one part of a facility to another. And, unlike metal detectors used today, the system quickly detects and differentiates between weapons and small communication transceivers such as cellular phones and two-way radios, which are security threats, if smuggled into secure areas. Most metal detecting systems in use today rely on transmitters located in the frame of the detector applying amagnetic field to induce electric currents in metallic objects. Such metal detectors then measure the perturbation of the imposed magnetic field caused by the presence of metallic objects. Such systems take advantage of their control of the applied field to generate a signal sufficient to discriminate the measured signals from environmental “noise” and detect the metal. Such scanning systems interact with heart pacemakers and metal plates in people, however, so all applied screening systems such as those in airports require that those searched must give their consent or endure a time-consuming, whole-body “pat down.”
.jpg) On the other hand, QFS’ passive magnetic-based screening systems do not require transmitters to induce electric currents. Rather they measure changes in the Earth’s magnetic field, isolating environmental interference without transmitting pulses of magnetic energy. Nevertheless, QFS’ screening system achieves markedly increased accuracy and sensitivity within mini-seconds at frequencies well below the environmental magnetic field level – with fewer false alarms than systems currently used. QFS’ systems do not interact with medical devices and as they do not require transmitters, it is possible to embed the systems in support columns, entrance turnstiles or door frames, thereby becoming inconspicuous to those who are screened, an important feature to many operators. The system is based on high-performance magnetic induction sensors that QFS developed under Department of Defense (DOD) and National Science Foundation (NSF) research programs.
Additional features of QFS’ screening portals include:
- a video and/or still camera to photograph each screened subject – and saved for a set time;
- colored indicators alert security operators to the exact area on persons where weapons may be present (see illustration above), thereby letting security personnel localize their pat-downs and other secondary security procedures; and
- adjacent sensors may be added to the portal structure that identifies anyone attempting to pass a detectable item around the structure.
Allegro Introduces a New Low-Voltage, Full-Bridge Brushless DC Motor Driver 
Allegro introduces a new full-bridge motor driver designed to drive low voltage bipolar brushless DC motors. Commutation of the motor is achieved by use of a single Hall element sensor to detect the rotational position of an alternating-pole ring magnet. A high density CMOS semiconductor process allows the integration of all the necessary electronics. This includes the Hall element sensor, the motor control circuitry and the full output bridge. Low-voltage design techniques have been employed to achieve device functionality down to 1.8 V VDD. This fully integrated single chip solution provides enhanced reliability (including reverse battery protection and output short circuit protection) and eliminates the need for any external support components.
Allegro’s A1442 employs a soft-switching algorithm to reduce audible switching noise and EMI interference. A micro power sleep mode can be enabled by an external signal, to reduce current consumption for battery management in portable electronic devices. This feature allows for the removal of a FET transistor for switching the device on and off. In addition, the device offers an active function for motor braking. Motor braking can be used to improve stop/start cycles for caller ID feature in vibration mode.
The A1442 is optimized for vibration motor applications such as cellular phones, pagers, electronic toothbrushes, hand-held video game controllers and low power fan motors. The small package outline and low profile make this device well suited for use in applications where printed circuit board area and component headroom are at a premium.
It is available in a lead (Pb) free (leadframe plating Nickel Palladium) 6-pin MLP microleadframe package for surface mount, with exposed pad for enhanced thermal dissipation. The 6-pin MLP/DFN (Suffix EW) package, with dimensions 1.5 mm by 2 mm by 0.4 mm, makes it the thinnest MLP currently in the marketplace. It is priced at $0.39 in quantities of 1,000 and has a 6 to 8 week typical lead-time to market.
New Design Flow Allows ZTE to Meet Strict EMI/EMC Requirements
Ansoft Corp. has announced a strategic partnership with ZTE Corp., China's largest listed
telecommunications equipment provider of customized network solutions for telecom carriers worldwide.
Using Ansoft signal and power integrity analysis software, ZTE engineers are now able to predict radiated emissions and induced interference from printed circuit boards (PCBs) and to examine multiple PCBs within a cabinet to determine trends for system-level emission. The new design methodology has allowed ZTE to eliminate expensive build-test-repeat iterations in their design cycle.
"Our engineers are very experienced in PCB design and needed to expand capabilities for EMI/EMC. Previously, we were using expensive and time-consuming prototyping and testing to make sure the design performance met requirements," said Mr. Zhu Shunlin, chief engineer of
the EDA group at ZTE. "Ansoft's design methodology and technical support team helped us solve this issue, improve product performance, reduce cost and speed our time to market. We have taken our R&D team's capabilities to the next level."
The design flow is comprised of Ansoft's HFSS, the industry-leading full-wave electromagnetic field simulation software; SIwave, a full-wave electromagnetic field simulator optimized for
PCB signal and power integrity analysis; and DesignerSI, an integrated schematic and design management front-end for signal integrity analysis and system verification. ZTE engineers perform board-level simulations in SIwave to produce accurate full-wave modeling and to develop design rules so they can design with EMC compliance in mind. They combine results from individual board simulations in more comprehensive HFSS simulations of full 3D systems
including multiple boards placed in a backplane and chassis. This design flow has allowed ZTE to improve signal integrity, reduce emissions and eliminate unnecessary shielding.
"With the increased clock speed and operating frequencies of today's PCBs, it is essential that companies adopt an electromagnetic-based design flow to understand the performance of
high-speed electronic products," said Thomas Flynn, vice president of sales at Ansoft. "It is an honor to partner with ZTE and help them achieve first-pass system success in designing their high-performance telecommunications equipment."
Clayton R. Paul, Mercer University Engineering Professor, To Receive IEEE Teaching Award
2.jpg) The IEEE has named Clayton R. Paul as the recipient of its 2007 Undergraduate Teaching Award, recognizing his sustained excellence and creativity in the preparation of instructional materials and inspirational teaching of undergraduate engineering students. A prolific author, he has devoted his life to promoting greater understanding of electromagnetic compatibility. The IEEE is the world’s leading professional association for the advancement of technology.
Sponsored by the IEEE Education Society, the award recognizes exceptional accomplishments in education with curricula pertaining to the fields represented by the IEEE membership.
Paul is the Sam Nunn Professor of Aerospace Systems Engineering and professor of electrical and computer engineering at the Mercer University School of Engineering in Macon, Ga. He has devoted his life to teaching undergraduates about electrical engineering, motivating high school students to consider careers in engineering and publishing textbooks and other instructional materials tailored to his courses. He also has been actively involved in IEEE student chapters as a faculty advisor.
In addition to teaching, Paul has held positions at the US Air Force Rome Air Development Center in Rome, N.Y., where he conducted extensive research in modeling crosstalk in multi-conductor transmission lines and printed circuit boards and at the IBM Information Products Division in Lexington, Ky. in the area of electromagnetic compatibility (EMC) design of electronic systems. He has written or co-authored 16 textbooks and other instructional materials and has published numerous technical papers in his primary research area of EMC.
Paul has a bachelor’s degree from The Citadel in Charleston, S.C., a master’s degree from the Georgia Institute of Technology in Atlanta, and a doctoral degree from Purdue University in Lafayette, Ind., all in electrical engineering. He is emeritus professor of electrical engineering at the University of Kentucky, where he was a faculty member for 27 years. An IEEE Fellow, he has won numerous awards for his teaching excellence and ability to inspire students.
Sypris Test & Measurement Relocates Chicago Calibration Lab
Sypris Test & Measurement, Inc., a subsidiary of Sypris Solutions, Inc., recently relocated its Chicago A2LA - accredited Calibrations Laboratory to a new suite within the same building. The newly renovated space is twice the size of the previous suite, which allows the Lab to expand its offerings and to more easily accommodate the growing customer demand.
“After experiencing a record breaking year in 2006, the Lab is looking forward to breaking that record again in 2007 with the new space and facility,” said Leonard Gaffney, district manager. The Chicago Lab will continue to offer calibration services throughout Illinois, Missouri, Iowa, Wisconsin, Minnesota and North Dakota in addition to continuing to support many of the Company’s domestic and international customers.
The Lab’s new address is 2055 Army Trail Road, Suite 114 – 116, Addison, IL 60101. The Lab phone (630-620-5800) and fax (630-620-0584) numbers will remain the same. |
