ISOLOOP MAGNETIC COUPLERS REPLACE OPTO-COUPLERS ABSTRACT Couplers, also known as "isolators" because they electrically isolate as well as transmit data, are wi Download at Google Play · Office PowerPoint. Explore Isoloop Magnetic Couplers with Free Download of Seminar Report and PPT in PDF and DOC Format. Also Explore the Seminar Topics. Explore IsoLoop Magnetic Couplers with Free Download of Seminar Report and PPT in PDF and DOC Format. Also Explore the Seminar Topics Paper on.
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Isoloop Magnetic Coupler - Download as Powerpoint Presentation .ppt /.pptx), PDF File .pdf), Text File .txt) or view presentation slides online. isoloop magnetic coupler - Download as Word Doc .doc), PDF File .pdf), Text File .txt) or read online. doc. IsoLoop Magnetic Couplers Replace Opto-Couplers in. Industrial Systems. A new generation of couplers weathers the storm of noise with high speed and.
Published on Dec 17, Abstract Couplers, also known as "isolators" because they electrically isolate as well as transmit data, are widely used in industrial and factory networks, instruments, and telecommunications. Every one knows the problems with optocouplers. They take up a lot of space, are slow, optocouplers age and their temperature range is quite limited. For years, optical couplers were the only option. Over the years, most of the components used to build instrumentation circuits have become ever smaller. Optocoupler technology, however, hasn't kept up.
In fig. Figure -2 For spin-dependent scattering to be a significant part of the total resistance, the layers must be thinner than the mean free path of electrons in the bulk material.
It is therefore not surprising that GMR was only recently observed with the development of thin film deposition systems. The spins of electrons in a magnet are aligned to produce a magnetic moment. Magnetic layers with opposing spins impede the progress of the electrons higher scattering through a sandwiched conductive layer.
In a giant magneto resistive sensor, the resistance of two thin ferromagnetic layers separated by a thin nonmagnetic conducting layer can be altered by changing the moments of the ferromagnetic layers from parallel to antiparallel.
The following chart shows a typical characteristic for a GMR material: Figure-3 Notice that the output characteristic is omnipolar, meaning that the material provides the same change in resistance for a directionally positive magnetic field as it does for a directionally negative field. This characteristic has advantages in certain applications. For example, when used on a magnetic encoder wheel, a GMR sensor using this material will provide a complete sine wave output for each pole on the encoder thus doubling the resolution of the output signal.
In a GMR, isolator data travels via a magnetic field through a dielectric isolation to affect that resistance elements arranged in a bridge configuration.
Figure-5 Basic circuit of Isoloop Magnetic Coupler. The current in the planar coil produce a magnetic field. The magnetic field produced by the field coil of the input affects the spin of electrons in the anti-ferromagnetic layers, reducing the resistance of the bridge sensors. The isolation transmitter is simply coil circuitry deposited on a layer between the GMR sensors layers and the thick film magnetic shielding layer see Figure 5. Current through this coil layer produce the magnetic field, which overcomes the anti ferromagnetic layers there by reducing the sensors resistance.
The manufacturing process allows thick film magnetic material to be deposited over the sensor elements to provide areas of magnetic shielding or flux concentration. Various op-amp configurations can be used to supply signal conditioning from the bridges outputs. This forms the basis of an isolation receiver. Single resistor elements are the smallest devices and require the fewest components, but they have poor temperature compensation and usually require the formation of some type of bridge by using external components.
Alternatively they can be connected in series with one differential amplifier per sensor resistor. Half bridges take up more area on a chip but offer temperature compensation, as both resistors are at the same temperature. Half bridges can be used as field gradient sensors if one of the resistors is some distance from the other.
They can function as field sensors if one of the resistors is shielded from the applied field. The large output signal of the GMR sensor element Introduction means less circuitry, smaller signal errors, less drift, and better temperature stability compared to sensors where more amplification is required to create a usable output.
The GMR Switch holds its precise magnetic operate point over extreme variations in temperature and power supply voltage. This is a low cost method. The current produces a magnetic field, which is proportional to the current in the planar coil. The resulting magnetic field produces a resistance change in the GMR material, which is separated from the planar coil by a high voltage insulating material.
Since the GMR is sensitive parallel to the plane of the substrate, this allows a considerably more compact construction than would be possible with Hall sensors. The resistance change in GMR material, which was caused by the magnetic field, is amplified by an electronic circuit and impressed upon the output as a reproduction of the input signal.
Since changes in the ground potential at the input, output or both doesnt produce a current in the planar coil, no magnetic field is created.
The GMR material doesnt change. In this way safe galvanic signal isolation is achieved and at the same time a corresponding common mode voltage tolerance.
High bandwidth. Widespread electrical and communications networks often have nodes with different ground domains. The potential difference between these grounds can be AC or DC, and can contain various noise components.
Grounds connected by cable shielding or logic line ground can create a ground loop-unwanted current flow in the cable.
Ground-loop currents can degrade data signals, produce excessive EMI, damage components, and, if the current is large enough, present a shock hazard. Galvanic isolation between circuits or nodes in different ground domains eliminates these problems, seamlessly passing signal information while isolating ground potential differences and common-mode transients. Adding isolation components to a circuit or network is considered good design practice and is often mandated by industry standards.
Isolation is frequently used in modems, LAN and industrial network interfaces e. Optocouplers transmit signals by means of light through a bulk dielectric that provides galvanic isolation Magnetic couplers transmit signals via a magnetic field, rather than a photon transmission, across a thin film dielectric that provides the galvanic isolation. As is true of optocouplers, magnetic couplers are unidirectional and operate down to DC. But in contrast to optocouplers, magnetic couplers offer the high-frequency performance of an isolation transformer, covering nearly the entire combined bandwidth of the two conventional isolation technologies.
The spin of electrons in a magnet is aligned to produce a magnetic moment. Magnetic layers with opposing spins magnetic moments impede the progress of the electrons higher scattering through a sandwiched conductive layer. This arrangement causes the conductor to have a higher resistance to current flow.
An external magnetic field can realign all of the layers into a single magnetic moment.
When this happens, electron flow will be less effected lower scattering by the uniform spins of the adjacent ferromagnetic layers.
This causes the conduction layer to have a lower resistance to current flow.
Figure 2—In both a and b, the A layers are the nonmagnetic conductive layer and the B layers are adjacent magnetic layers of opposing orientation. Layers with parallel magnetic moments will have less scattering at the interfaces, longer mean free paths, and lower resistance.