Power Cord Research Articles

Tapped Energy

AbstractWhether in an espresso machine or a bulldozer — embedded technical microsystems are in demand. Through “energy harvesting”, it should be possible to supply them with power from their immediate surroundings, without the need of batteries or power cords.

Noninvasive current sensor for household appliances and compensation for installation variation

The lack of natural resources requires a more efficient use of energy. This study proposes a noninvasive coil current sensor for energy efficiency in the home. The proposed sensor is used to detect current in two-wire power cords used by household appliances. Moreover, the proposed sensor has no contact with the conductors in the power cords, ensuring a safe measurement process. Mathematical models and experiments are conducted to verify the characteristics and performance of the proposed device. In addition, this study develops relevant algorithms and the method for reducing installation variation. Using the developed algorithms, the measurement errors caused by an installation gap were reduced to less than 3%. The information provided by the current sensor supports home energy management systems and encourages energy-saving behaviors for every household member, resulting in an increasingly efficient energy usage.

Experiments on ferrimagnetism

Ferrimagnetism undoubtedly deserves a proper place in the undergraduate laboratory on electricity and magnetism. Four student experiments on ferrimagnetism are considered: (i) the hysteresis loops and permeability of a ‘soft’ ferrite; (ii) the differential permeability versus a dc bias; (iii) the frequency dependence of the complex permeability and (iv) the electromagnetic interference suppression by ferrite chokes and beads. Two ferrite cores taken off a low-frequency choke and a power cord are used. The measurements are simple and straightforward and show the important properties of ferrites and their applications. The values of the permeability of the ferrite core determined in experiments (i)–(iii) are in reasonable agreement. The frequency dependence of the complex permeability of the ferrites is similar to that given by the manufacturers. The capability of absorbing electromagnetic waves in a definite frequency range shown in experiment (iv) demonstrates one of the principles of Stealth technology. The equipment necessary for the experiments can be found in many student laboratories.

Bacterial power cords

Geochemical reactions in upper layers of marine sediments are coupled to those in deeper zones. It turns out that centimetre-long bacterial filaments acting as electrical cables are the metabolic link between the layers. See Article p.218 A major challenge for multicellular organisms is that of supplying every cell with food and oxygen. Nils Risgaard-Petersen and colleagues report a surprising solution to the problem, arrived at by multicelluar filamentous Desulfobulbaceae bacteria several centimetres long, living in the upper layers of marine sediments sampled in Aarhus Bay, Denmark. These organisms seem to function as living electric cables, transporting electrons from sulphides generated in organic matter in deeper anoxic sediments to the oxygen available in the surface layers. These living micro-cables raise a host of topics for future research, and could also find technological applications.

Mobile Applications as Tools to Support Embodied Learning

Mobile learning (mLearning) is a rapidly expanding area of educational research. Theorists, researchers, and instructional designers are excited about the potential contributions of mobile technology to the field of education. Mobile tools such as Apple’s iPad or Galaxy Tab have sparked this interest based on their ability to provide high-powered computing within a small, extremely portable form factor. Learners are no longer constrained by the desktop or the power cord of a laptop. Unfortunately, much of mLearning research has focused on transferring eLearning on to mobile devices, instead of investigating the unique characteristics of mobile tools that can be used to define mLearning as a distinct type of learning. This paper begins the task of situating mLearning as a distinct type of learning by first considering the theoretical and pedagogical affordances unique to it. Then, the authors transition into a discussion of embodied learning and how the literature related to this field supports the use of mobile tools for educational purposes that go well beyond the deliver of eLearning instructional content. From there, the authors move to a discussion of the logistical challenge of melding mobile tools within formal learning environments. Next, the paper reports the results of an investigation into the current state of mLearning applications and how the majority of these applications fail to leverage the hardware features of mobile tools that can potential result in deeper understanding of concepts and skills. Finally, the authors provide implications and future directions for developers and educators.

How was Haiti?

How was Haiti? Sadath Sayeed "She smelled of milk and urine. Chacko marveled at how someone so small and undefined, so vague in her resemblances, could so completely command the attention, the love, the sanity of a grown man." —Arundhati Roy from The God of Small Things Father and Son Twenty minutes before I was to be taxied to the airport in Port-au-Prince, the baby boy handed to me did not breathe continuously. He didn't breathe at all. Born a few hours earlier at home—probably in one of the hundreds of make-shift tent cities. I did ask if the baby cried after he came out of mom. Yes. He didn't suckle well and stopped crying. Dad decided to get help. Climbed onto a moped with his baby wrapped in a blanket. Must have tucked him under one arm and rode between piles of rubble to the closest health care facility. People at this other place tried to help his baby boy breathe. They pushed air into his mouth like you are doing. After a few minutes, they said that they couldn't help anymore. "Go to the University hospital." From a shirt sleeve pocket, he pulled a crumpled white piece of paper with some writing scribbled on it. I gathered it documented this last visit. They took the time to hand him a note before they sent him on his way. What did Dad think? Thanks for the note. Okay, now what? Swaddle my baby. Tuck him under one arm. Hop on my moped. Strained Resources L'Université d'État d'Haïti has been the main teaching hospital for all of the country for decades. Many, if not most, formally trained Haitian health care providers have spent some time in Port-au-Prince at this institution. As important as it is, it has suffered from neglect over many, many years. The earthquake made matters exponentially worse. [End Page 98] Dad must have been directed to the pediatric service when he arrived. There, a few Haitian pediatric residents and nurses were doing what they did every morning. Tending to an overcrowded patient population of babies, children, and parents. The pediatrics building was left uninhabitable. All inpatient and outpatient care took place on a street where the tents had been erected. In the ICU, tent twenty beds filled a space probably meant for ten military style cots. Metal cribs and full adult hospital beds were jammed next to one another to fill every possible nook. Parents slept on the adult beds with their sick children or underneath the cribs. Siblings too. Outside, hundreds of parents would line up starting at six a.m. and stand in line for hours so that they could get their children seen in a couple of smaller tents that were used to run the outpatient clinics. Moms would fan their kids under the shade of trees on the side of the road. Feed them some milk or juice while they waited. Smile at us passers-by. They seemed to possess a bottomless well of patience. Power cords with extension wires littered the street-hospital floor under the canopy. When it rained, we were only modestly concerned about electrocution. A single 1950's style metal desk with two worn out chairs greeted visitors to the entry way and was usually occupied by some of the medical staff. A single, large metal fan that had collected enough dust and soot in its circular cage to look bearded hummed a breeze toward the desk. A bottomless well of patience and resiliency. In the popular media, this last word has been thrown around a lot to describe the character of the Haitian people. It is insufficient. Their adversity is truly absurd. Sense cannot be made of the scene in the pediatrics tents months after the earthquake struck, nor elsewhere on that campus, let alone outside its walls. The local medical staff hadn't been paid a dime in many months even prior to the earthquake. They suffered unimaginable losses during the earthquake. They still came to work. "We love our children. They love us too." What so many of us think of as charity...

Ask George

In this column, BI&T features questions and answers between AAMI members and Joint Commission expert George Mills. Become part of the discussion and ask questions about those subjects that matter to you the most. You can submit your Joint Commission question at this link: www.aami.org/tmcconnect/askgeorge.html. Or to join AAMI's Joint Commission e-forum, which is open to all AAMI members, visit www.aami.org/tmcconnect/discussiongroups.html. Some of the questions and answers may have been edited for space, style, and clarity.In discussions around best practice maintenance strategies for endoscopes, there is some confusion regarding which scopes are involved. At first, it seemed all scopes of rigid and flexible origin, but then I heard that solid scopes were to be treated the same as OR instruments. I am assuming rigid scopes are solid scopes. Are they therefore handled the same as OR instruments with OR/central sterile oversight, and all flexible scopes are for clinical engineering oversight?The driving issue is the concern for cross contamination. I have consistently asked that both flexible and rigid endoscopes be added to the medical equipment inventory, on a voluntary basis, to create another look at the reprocessing environment affecting scopes.Is there a Joint Commission standard that requires life-support equipment be plugged into the red emergency power outlets? I've never heard of this, but a consultant is referencing EC.02.04.01 EP2 and EC.02.05.03 as the standards this requirement falls under.There is a requirement for emergency power to be supplied in the Utilities Management section for those items listed in EC.02.05.03, such as “equipment that could cause patient harm when it fails, including . . . blood, bone, and tissue storage systems.” The Joint Commission expects the organization to conduct a risk assessment whenever these decisions are required, to identify proper response to the potential risk.A few years ago, some people believed that The Joint Commission required defibrillators to be plugged into receptacles that were also powered by the emergency power system. This was never a Joint Commission requirement, but an opportunity for the organization to determine what best met the needs of the organization.I have a question related to relocatable power taps. Our hospital is installing a new electronic medical record system. They'll be integrating our ventilators so that data will flow into the patient record. The solution being used on mobile equipment is a small, 12-volt PC that will attach permanently to each vent. IT wants to use a hospital-grade, multiple-outlet adapter. The small transformer would be plugged into the strip. The outlet strip is hefty enough to handle the ventilator as well as the humidifier. We would then have only one power cord for the three devices. As long as we perform our electrical safety tests on the devices as a group, is it acceptable to use these for this purpose?This was discussed at a Healthcare Interpretation Task Force meeting without resolution. NFPA 70, 99 and 101 all have regulations that control the electrical components in a patient room, none supporting use with medical equipment. Pending formal action, The Joint Commission has allowed organizations to conduct a risk assessment to determine the appropriateness of these power taps. At a minimum, we have said that they should be hospital grade, prohibit “daisy-chaining” (linking one power tap from another), and confirm the circuits supplying power are adequate.Regarding rental equipment documentation: If we use a reputable company that we have used for many years and have a good relationship with, can we use their test and safety inspection documents as our own?This is up to your organization to manage, as The Joint Commission does not accredit the service company, but your organization. The requirement for the equipment to be tested and safety inspections completed is the accredited organization's responsibility, and you should be able to show why your process is acceptable. Some organizations conduct random sampling of the work performed by the contracted service to document effectiveness.

A Flexible Inductive Coil Tag for Household Two-Wire Current Sensing Applications

This paper presents a flexible inductive coil tag for sensing the electric current in the two-wire power cords of household goods. The tag is fabricated using a complementary metal-oxide semiconductor compatible SU-8 flexible technology which provides unique device characteristics of low-cost, reliability and pervasiveness. With a 30-turns coil design in an area of 0.5 × 1 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , the coil tag can provide sensitivity of 18 and 21 μV/A for detecting 50-and 60-Hz electric current in the ampere regime, respectively.

Special issue on energy harvesting in wireless networks

Energy consumption has emerged as a key issue for designing next generation wireless networks. Having to periodically recharge mobile devices using power cords hampers the mobile operation of the devices. On the other hand, energy-constrained wireless networks, such as sensor networks, have limited lifetime due to the difficulty in replacing or recharging batteries in the nodes. Energy harvesting is a promising approach that addresses these issues as it powers mobile devices and, in general, wireless networks by scavenging energy from the ambient environment. Specifically, the networks can be made self-sustaining by harvesting energy from rich sources including solar power, electromagnetic waves, thermal energy, wind energy, salinity gradients, and kinetic energy. The recent emphasis on green communications also provides a strong motivation for developing energy harvesting based communication techniques. This has become all the more urgent because the electricity consumption of the fast expanding networks that handle mobile devices has grown rapidly, and will soon contribute significantly to global warming.

Powering a Ventricular Assist Device (VAD) With the Free-Range Resonant Electrical Energy Delivery (FREE-D) System

Wireless data communication technology has eliminated wired connections for data transfer to portable devices. Wireless power technology offers the possibility of eliminating the remaining wired connection: the power cord. For ventricular assist devices (VADs), wireless power technology will eliminate the complications and infections caused by the percutaneous wired power connection. Integrating wireless power technology into VADs will enable VAD implants to become a more viable option for heart failure patients (of which there are 80 000 in the United States each year) than heart transplants. Previous transcutaneous energy transfer systems (TETS) have attempted to wirelessly power VADs ; however, TETS-based technologies are limited in range to a few millimeters, do not tolerate angular misalignment, and suffer from poor efficiency. The free-range resonant electrical delivery (FREE-D) wireless power system aims to use magnetically coupled resonators to efficiently transfer power across a distance to a VAD implanted in the human body, and to provide robustness to geometric changes. Multiple resonator configurations are implemented to improve the range and efficiency of wireless power transmission to both a commercially available axial pump and a VentrAssist centrifugal pump [3]. An adaptive frequency tuning method allows for maximum power transfer efficiency for nearly any angular orientation over a range of separation distances. Additionally, laboratory results show the continuous operation of both pumps using the FREE-D system with a wireless power transfer efficiency upwards of 90%.

모발건조기의 전기화재 위험요소에 따른 화재 감정기법 연구

In this study, investigation and appraisal method for the scene of a fire according to electrical fire hazards of hair dryer which is usually used at living space are presented. Hair dryer is briefly composed of heating part, wind part and control part. Electrical fire hazards of hair dryer are insulation destruction of power cord, ignition by overheat of heating coil, scattering spark on inside dust, overheat of motor by fan shackle, ignition by carelessness of user, and so on. Fire cause by hair dryer can be perceived through investigation about half-disconnection of power cord, contact badness of power plug, verification of heating coil, fan and switch. These results are expected to be utilized effectively in a countermeasure to prevent an electrical fire by hair dryer.

A Secure Smart-Metering Protocol Over Power-Line Communication

A smart-metering system is a system that meters electricity, gas, and water consumption and manages their supply by controlling measuring devices remotely. Power-line communication (PLC) does not require a separate communication line and can be easily installed by utilizing power-line infrastructure. PLC also allows users to easily connect measuring devices to the PLC network by plugging the power cord into an electrical outlet. Therefore, a smart-metering system over PLC has been considered as one of the most appropriate technologies for meter reading and automatic control, which are essential in realization of a smart grid. We propose a secure smart-metering protocol including: 1) key materials generation and provisioning to devices without exposure; 2) initialization to authenticate devices in the network and share keys between devices before exchanging data, (3) secure transmission of meter-reading data, and 4) revocation management to handle discarded devices from the network. Especially, our protocol provides strong authentication of devices and data: It prevents a single point of failure by adopting secret sharing through multiple certificate authorities. It also reduces the risk of denial-of-service attacks on the server by hop-by-hop authentication for data transmitted from terminal nodes to the server.

ATTENUATION IN EXTENDED STRUCTURES COATED WITH THIN MAGNETO-DIELECTRIC ABSORBER LAYER

Thin absorbing layers containing magnetic alloy or ferrite inclusions can be efiectively used for attenuating common-mode currents on extended structures, such as power cords, cables, or edge- coupled microstrip lines. An analytical model to evaluate attenuation on the coaxial line with the central conductor coated with a magneto- dielectric layer is proposed and validated by the experiments and numerical modeling. The analytical model is validated using available magneto-dielectric samples of difierent thicknesses. This model can serve for comparing and predicting the absorptive properties of difierent samples of magneto-dielectric materials, whose compositions may be unknown, but dielectric and magnetic properties can be determined by independent measurements over the specifled frequency ranges. From modeling the absorption in a coaxial line with a wrapped central conductor, it could be concluded whether it is reasonable to use this particular material in such applications as a shield on an Ethernet or other cable, for reducing potential common-mode currents and unwanted radiation in the frequency range of interest.

Transfer of Electricity in Energy Engineering

This paper aims to suggest and research a revolutionary method-transfer of electricity in outer Space with distance of hundreds of millions kilometers by ultra-cool plasma cables. Theory of plasma cable transferring is offered, developed and its possibilities researched. Offers conclusions from the research of a revolutionary new idea-transferring electric energy in the hard vacuum of outer space wirelessly, using a plasma power cord as an electric cable (wire).Transference of hundreds kilowatts of energy to Earth’s Space Station, transferring energy to the Moon or back, transferring energy to a spaceship at distance 100 million of kilometers, the transfer energy to Mars when one is located at opposite side of the distant Sun, transfer colossal energy from one of Earth’s continents to another continent wirelessly – using Earth’s ionosphere as cable, using Earth as gigantic storage of electric energy, using the plasma ring as huge MagSail for moving of spaceships.

P204 Travel with CPAP machines: how frequent and what are the problems?

Introduction and Objectives Obstructive sleep apnoea (OSA) is common and most patients are relatively young. CPAP is the standard treatment. This questionnaire survey aimed to improve the understanding of the problems which patients on CPAP face during travel and while away from home. Methods 150 patients on CPAP were randomly selected from our patient database and sent a postal questionnaire. They were asked the number of times they had travelled in the last 2 years and specific questions about the last three trips. These included mode of travel, duration of trip, change in CPAP use, problems with transport and use of CPAP. Patients were asked to specifically document whether they used CPAP during travel. All patients are offered a letter regarding their CPAP therapy to facilitate travel. Results 101 questionnaires were returned (men=69, mean age=60.5 years). 58 (men=50, mean age 59.4 years) had travelled in the last 2 years on 211 occasions. Data were collected for 139 trips. In 13 trips the CPAP machine was not taken. Reasons included weight, space and check in concerns. 84 trips were within Europe and 7 to North America. 93 trips were by air. On 22 trips, respondents reported the “CPAP letter” was needed for check in. In 7 of the 93 trips by air, problems with checking in the CPAP machine were encountered. In all but 4 trips the CPAP machine was carried as hand luggage. In 33 trips problems with use of CPAP due to the short power cord was reported. CPAP was used less often abroad. CPAP was rarely used during travel. Individual statements highlighted problems with security and check-in. Conclusions Patients with OSA travel abroad frequently and usually take their CPAP machine with them. In a significant number there are problems with check-in of the CPAP machine and we strongly recommend patients are provided with a “CPAP letter”. Improved dissemination of information is needed to patients and airport staff regarding OSA and CPAP. We recommend patients carry extension cords and power adaptors. The reason for less use of CPAP abroad is not clear and needs further explanation.

Assessment of electromagnetic interference suppression performance of ferrite core loaded power cord

An evaluation methodology of the electromagnetic interference (EMI) suppression performance of a ferrite core clamped onto a power cord under its actual operating condition is proposed. With known electrical parameters of a ferrite core, the true EMI suppression performance of the ferrite core at a specific location on a power cord under its intended operating condition can be determined. Based on a two-probe inductive coupling approach, the current probes are clamped on the power cord and the EMI attenuation of a ferrite core loaded power cord can be assessed more objectively without the actual operation interrupted. Taking into account the common-mode impedance of the ferrite core and the common-mode impedances of the power cord terminated with the intended source and load, the true EMI suppression performance of the ferrite core located at different positions along the power cord can be evaluated with confidence. The measured EMI suppression has also been validated with the simulation results using the transmission line model.

Electrical Safety in the Operating Room

demonstrates that even today, theoperating room (OR) is not always a safe workingenvironment. Despite years of education on electricalsafety, combined with policies and precautions dictated bynational watchdog agencies such as the National FirePrevention Agency, a nurse sustained a serious, life-threatening electrical shock while performing her duties inthe OR. How could this happen, given our advancedunderstanding of both the physics and hazards of electric-ity? To understand and learn from this important casereport, we begin with a brief review of some relevantelectrical safety principles.Electricity can stimulate muscle cells to contract, and canthus be used therapeutically in devices such as pacemakersor defibrillators. Electrical current can also trigger grandmal seizures, and this effect is used beneficially in electro-convulsive therapy. However, contact with a large electri-cal current, whether alternating current (AC) or directcurrent, can lead to injury or death.Utility companies supply electrical energy in the form ofAC of 120 or 230 V at a frequency of 60 Hz (50 Hz in Europe).The60Hzreferstothenumberoftimesthatthecurrentcyclesper second. A typical power cord consists of two conductors.One designated as “hot” carries the current to the load; theother is neutral or “ground” and it returns the current to thesource. The root mean square potential difference betweenthe two is 120 V.To receive a shock, one must contact an electrical circuit attwo points, and there must be a potential difference thatcauses current to flow between those points. When an indi-vidual contacts a source of electricity, damage usually occursin one of two ways. First, the electrical current can disrupt thenormal electrical function of cells. Depending on its magni-tude, the current can contract muscles, paralyze respiration,cause seizures, or lead to ventricular fibrillation. The secondmechanism involves the dissipation of electrical energythroughout the tissues. An electrical current passingthrough any resistance increases the temperature of thatsubstance. The power dissipated as heat equals the squareof the current multiplied by the resistance (

Forensic Engineering Critique Of The Methodology Eliminating Fire Cause Possibilities

In A Case Involving A Residential Fire With Fatalities, Plaintiff Experts Alleged That The Fire Originated In A Bedroom As A Result Of An Electrical Failure In An Oscillating Pedestal Fan. At The Time Of The Fire, The Fan Was Plugged Into A Six Foot Extension Cord That Was Lying On The Floor Under The Bed And Plugged Into A Standard 115 Volt Duplex Receptacle. The Plaintiffs, Specific In Their Allegations, Opined That The Failure Occurred In The Rotary Switch That Controlled The Speed Of The Fan Even Though No Physical Evidence Of A Failure Of That Nature Was Identified Or Collected During The Analyses Of The Fire Scene. Since No Physical Evidence Of A Failure Was Identified, Nfpa 921, Guide For Fire &amp; Explosion Investigations, Requires That All Other Potential Ignition Sources In The Area Of Origin Be Eliminated As A Possible Cause. Plaintiffs Eliminated The Power Cord For The Fan, The Extension Cord And The Cord Plug And Cord Receptacle Connection Under The Theory That The Material Was Pvc With A Vw-1 Fire Rating. Plaintiffs Testified That The Self Extinguishing Characteristics Of Vw-1 Material Were Such That, Even With An Electrical Failure In One Of Those Components That Resulted In The Ignition Of The Material, There Would Be Insufficient Heat Released To Ignite The Box Spring For The Bed. Plaintiffs Also Eliminated Improperly Discarded Smoking Material As A Potential Cause.Efendants Were In Sharp Disagreement With Plaintiff Case In Chief Regarding The Elimination Of The Vw-1 Materials As A Potential Fire Cause, Since The Material Will Combust In Situations With A Sustained Electrical Fault. Defendants Conducted Tests Which Not Only Demonstrated An Electrical Failure With Ignition At The Extension Cord Plug Receptacle Interface, But Also That The Burning Vw-1 Pvc Released Sufficient Heat Energy To Ignite A Box Spring Similar To The Box Spring Involved In The Fire. The Results Of Those Tests Assisted In The Resolution Of The Case Prior To Trial.

Power Cords Linked to Sparks, Fires

Biomedical Safety & Standards 39(21):p 161,163, December 1, 2009. | DOI: 10.1097/01.BMSAS.0000363971.93200.ee

Development of a Compact Switched-Reluctance Motor Drive for EV Propulsion With Voltage-Boosting and PFC Charging Capabilities

This paper presents a compact battery-powered switched-reluctance motor (SRM) drive for an electric vehicle with voltage-boosting and on-board power-factor-corrected-charging capabilities. Although the boost-type front-end DC/DC converter is externally equipped, the on-board charger is formed by the embedded components of SRM windings and converter. In the driving mode, the DC/DC boost converter is controlled to establish boostable well-regulated DC-link voltage for the SRM drive from the battery. During demagnetization of each stroke, the winding stored energy is automatically recovered back to the battery. Moreover, the regenerative braking is achieved by properly setting the SRM in the regenerating mode. The controls of two power stages are properly designed and digitally realized using a common digital signal processor. Good winding current and speed dynamic responses of the SRM drive are obtained. In addition, the static operation characteristics are also improved. In the charging mode, the power devices that were embedded in the SRM converter and the three motor-phase windings are used to form a buck-boost switch-mode rectifier to charge the battery from utility with good power quality. All constituted circuit components of the charger are placed on board, and only the insertion of power cords is needed.