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Thorlabs: Fast Photodiode 201/579-7227 Silicon Photo-Diode Detector | ![]() |
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US $135.00 | 13d 10h 40m |
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Thorlabs: Fast Photodiode Silicon Photo-Diode Detector: Laser Opics: For Parts | ![]() |
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US $45.00 | 22d 15h 20m |
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Silicon Diode Detectors
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Can you answer my question concerning frequency detection?
My question was: Where can I buy a radio frequency detector that can detect frequencies in the low 3 to 20 Hz range?
My answer was:
I was told that if I'm going to use a coil, a diode and an LED. I need to have some sort of amplifier before the diode, since the signal that I pick up would almost certainly be less than the 0.6V threshold voltage of a silicon diode. And that I may also wish to put a capacitor across the coil to remove higher frequencies.
What is a COIL, DIODE or LED and CAPACITOR? Where can I get one of these already made?
What kinds of stores sell them?
If you can add or expound on this I would appreciate it.
Thank you for your answer
try with google, the research engine
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No items matching your keywords were found.
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Thorlabs: Fast Photodiode 201/579-7227 Silicon Photo-Diode Detector | ![]() |
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US $135.00 | 13d 10h 40m |
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Thorlabs: Fast Photodiode Silicon Photo-Diode Detector: Laser Opics: For Parts | ![]() |
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US $45.00 | 22d 15h 20m |
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THORLABS DET100 400-1100nm, silicon photo-diode laser beam detector | ![]() |
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US $99.00 | 3d 9h 33m |
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Thorlabs: Fast Photodiode 201/579-7227 Silicon Photo-Diode Detector | ![]() |
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US $135.00 | 13d 10h 40m |
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15 pcs - 1SS99 NEC Silicon Schottky Detector & Mixer Diode | ![]() |
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US $6.95 | 15d 19h 28m |
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Thorlabs: Fast Photodiode Silicon Photo-Diode Detector: Laser Opics: For Parts | ![]() |
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US $45.00 | 22d 15h 20m |
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RARE! Detector Silicon Diode D103 (USSR-1969). 15 PCS | ![]() |
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US $15.00 | 17d 12h 31m |
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200 pcs - 1SS99 NEC Silicon Schottky Detector & Mixer Diode | ![]() |
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US $43.50 | 1d 9h 12m |
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THORLABS DET100 400-1100nm, silicon photo-diode laser beam detector | ![]() |
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US $99.00 | 3d 9h 33m |
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Planar Silicon Strip Radiation Detectors $197.72 Planar silicon strip sensors became very popular in the last two decades in inner tracking systems of largescale particle physics experiments, like the CMS detector at CERNs new particle accelerator LHC (Large Hadron Collider). With its more than 24,000 sensors it currently represents the largest silicon tracker in the world. This book reviews the quality assurance scheme established for testing those silicon sensors. It describes the full readout chain and delivers results from first tests of the tracker as a whole. The book concludes with a discussion about conceptual problems in the current design and proposes potential improvements for future projects like the proposed International Linear Collider. Author: Bergauer, Thomas Binding Type: Paperback Number of Pages: 296 Publication Date: 2009/01/01 Language: English Dimensions: 9.00 x 6.00 x 0.62 inches |
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Development of Advanced Silicon Drift Detectors $46.31 No Synopsis Available |
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The Physics of Particle Detectors $122.67 Here is a comprehensive introduction to the physical principles and design of particle detectors, covering all major detector types in use today. After discussing the size and energy scales involved in different physical processes, the book considers nondestructive methods, including the photoelectric effect, photomultipliers, scintillators, Cerenkov and transition radiation, scattering and ionization, and the use of magnetic fields in drift and wire chambers. A complete chapter is devoted to silicon detectors. In the final part of the book, Green discusses destructive measurement techniques. Throughout, he emphasizes the physical principles underlying detection and shows, through appropriate examples, how those principles are best utilized in real detectors. Exercises and detailed further reading lists are included. Author: Green, Dan/ Ericson, T./ Landshoff, P. Y. Series Title: Cambridge Monographs on Particle Physics, Nuclear Physics and Cosmology Series Number: 12 Binding Type: Paperback Number of Pages: 376 Publication Date: 2005/07/14 Language: English Dimensions: 6.69 x 9.60 x 0.77 inches |
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Compound Semiconductor Radiation Detectors (Hardcover) $333.37 "Although elemental semiconductors such as silicon and germanium are standard for energy dispersive spectroscopy in the laboratory, their use for an increasing range of applications is becoming marginalized by their physical limitations, namely the need for ancillary cooling, their modest stopping powers, and radiation intolerance. Compound semiconductors, on the other hand, encompass such a wide range of physical and electronic properties that they have become viable competitors in a number of applications. Compound Semiconductor Radiation Detectors is a consolidated source of information on all aspects of the use of compound semiconductors for radiation detection and measurement. Bringing together information scattered across many disciplines, this book summarizes the current status of research in compound semiconductor radiation detectors. It examines the properties, growth, and characterization of compound semiconductors as well as the fabrication of radiation sensors, with particular emphasis on theX- and gamma-ray regimes. It explores the limitations of compound semiconductors and discusses current efforts to improve spectral performances, pointing to where future discoveries may lie. A timely resource for the established researcher, this book serves as a comprehensive and illustrated reference on material science, crystal growth, metrology, detector physics, and spectroscopy. It can also be used as a textbook for those new to the field of compound semiconductors and their application to radiationdetection and measurement"-- |
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Silicon Carbide $93.99 Silicon carbide (SiC), also known as carborundum, is a compound of silicon and carbon with a chemical formula SiC. It occurs in nature as the extremely rare mineral moissanite. Silicon carbide powder has been massproduced since 1893 for use as an abrasive. Grains of silicon carbide can be bonded together by sintering to form very hard ceramics which are widely used in applications requiring high endurance, such as car brakes and ceramic plates in bulletproof vests. Electronic applications of silicon carbide as light emitting diodes and detectors in early radios were first demonstrated around 1907, and nowadays SiC is widely used in hightemperature/highvoltage semiconductor electronics. Large single crystals of silicon carbide can be grown by the Lely method; they can be cut into gems known as synthetic moissanite. Silicon carbide with high surface area can be produced from SiO2 contained in plant material. Author: Surhone, Lambert M./ Timpledon, Miriam T./ Marseken, Susan F. Binding Type: Paperback Number of Pages: 138 Publication Date: 2010/07/18 Language: English Dimensions: 6.00 x 9.02 x 0.32 inches |
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Aircraft Detectors $24.99 Aircraft Detectors - Photographic Print |
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NonCrystalline Silicon for Uncooled Infrared Detection $176.84 The increasing popularity of infrared (IR) detectors in thermal imaging and pollution control is progressively stimulating the industry to enhance the detection efficiency, and ultimately the performancecost ratio of IR cameras. Developing new IRsensitive materials, operating at room temperature without cooling, is undoubtedly a winning strategy which this book adopts by investigating the properties of noncrystalline silicon, with emphasis on borondoped hydrogenated amorphous silicon, used as resistive material for microbolometers. The contents are combined in order to drive professionals in IR sensors, as well as material scientists and graduate students in applied physics and engineering, from basic design parameters, such as temperature coefficient of resistivity and noise, down to the specifications for material deposition. Featuring a blend of theory and experiments (Raman spectroscopy, Xray diffraction, optical absorption and resistivity measurements), the analysis encompasses the effects of BCl3doping and hydrogenation on the electronic structure, phonon spectra and electrical transport of amorphous and microcrystalline silicon materials. Author: Pitassi, Stefano Binding Type: Paperback Number of Pages: 266 Publication Date: 2009/07/01 Language: English Dimensions: 9.00 x 6.00 x 0.60 inches |
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DIODE $12 When these electrical items fail there is little choice but to renew - With this genuine Suzuki par.. |
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Particle Detectors $60.67 No Synopsis Available |
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Goose Motion Detectors(Pack of 24) $12.5 HONKING GOOSE MOTION DETECTOR. This will get the intruders attention. These wholesale bulk cheap discount motion detectors can go anywhere. |
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Silicon $116.03 No Synopsis Available |
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US Army Engineers Using Mine Detectors $79.99 US Army Engineers Using Mine Detectors - Premium Photographic Print |
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Escort 9500i & 9500ix Radar Detector, Escort - Radar Detectors - Radar Detectors $599.94 Radar Detectors by Escort. Escort 9500ix Radar Detector Features - The Escort 9500ix Radar Detector provides 360-degrees of all-band radar and laser detection. Completely immune to police radar detector-detectors. TrueLock Signal Rejection uses GPS to eliminate false alerts by location and frequency-no more false alarms. Variable Speed Sensitivity provides protection based on vehicle speed-no parking-lot false alerts. SpeedAlert announces vehicle speed during each alert. Escort 9500i Radar, Escort 9500ix Radar Detector - Videos, Installations & Reviews. For the top selection of Escort Radar Detectors shop online today. The Escort 9500i Radar, Escort 9500ix Radar Detector - Videos, Installations & Reviews will improve and personalize your vehicle. Radar Detectors by Escort - selected by many auto enthusiasts in the top automotive discussion forums. Escort 9500ix Radar Detector for your vehicle will deliver the results you are looking for! Escort 9500ix Radar Detector - Radar Detectors - Radar Detectors. |
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Digital Illuminance Meter LX1330B 200000 Lux Luxmeter |
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DT-1301 Digital LCD Lux Foot-candle Luxmeter Light Meter |
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2 Valve Superhet using car valves and Altoids tins
Eddy current
Explanation As the circular plate moves down through a small region of constant magnetic field directed into the page, eddy currents are induced in the plate. The direction of those currents is given by Lenz's law. When a conductor moves relative to the field generated by a source, electromotive forces (EMFs) can be generated around loops within the conductor.
These EMFs acting on the resistivity of the material generate a current around the loop, in accordance with Faraday's law of induction. These currents dissipate energy, and create a magnetic field that tends to oppose the changes in the field. Eddy currents are created when a moving conductor experiences changes in the magnetic field generated by a stationary object, as well as when a stationary conductor encounters a varying magnetic field. Both effects are present when a conductor moves through a varying magnetic field, as is the case at the top and bottom edges of the magnetized region shown in the diagram.
Eddy currents will be generated wherever a conducting object experiences a change in the intensity or direction of the magnetic field at any point within it, and not just at the boundaries. The swirling current set up in the conductor is due to electrons experiencing a Lorentz force that is perpendicular to their motion. Hence, they veer to their right, or left, depending on the direction of the applied field and whether the strength of the field is increasing or declining. The resistivity of the conductor acts to damp the amplitude of the eddy currents, as well as straighten their paths. Lenz's law encapsulates the fact that the current swirls in such a way as to create an induced magnetic field that opposes the phenomenon that created it. In the case of a varying applied field, the induced field will always be in the opposite direction to that applied. The same will be true when a varying external field is increasing in strength. However, when a varying field is falling in strength, the induced field will be in the same direction as that originally applied, in order to oppose the decline. An object or part of an object experiences steady field intensity and direction where there is still relative motion of the field and the object (for example in the center of the field in the diagram), or unsteady fields where the currents cannot circulate due to the geometry of the conductor. In these situations charges collect on or within the object and these charges then produce static electric potentials that oppose any further current.
Currents may be initially associated with the creation of static potentials, but these may be transitory and small. Eddy currents generate resistive losses that transform some forms of energy, such as kinetic energy, into heat. In many devices, this Joule heating reduces efficiency of iron-core transformers and electric motors and other devices that use changing magnetic fields. Eddy currents are minimized in these devices by selecting magnetic core materials that have low electrical conductivity (e.g., ferrites) or by using thin sheets of magnetic material, known as laminations. Electrons cannot cross the insulating gap between the laminations and so are unable to circulate on wide arcs. Charges gather at the lamination boundaries, in a process analogous to the Hall effect, producing electric fields that oppose any further accumulation of charge and hence suppressing the eddy currents.
The shorter the distance between adjacent laminations (i.e., the greater the number of laminations per unit area, perpendicular to the applied field), the greater the suppression of eddy currents. The conversion of input energy to heat is not always undesirable, however, as there are some practical applications. One is in the brakes of some trains known as eddy current brakes. During braking, the metal wheels are exposed to a magnetic field from an electromagnet, generating eddy currents in the wheels. The eddy currents meet resistance as charges flow through the metal, thus dissipating energy as heat, and this acts to slow the wheels down.
The faster the wheels are spinning, the stronger the effect, meaning that as the train slows the braking force is reduced, producing a smooth stopping motion. Strength of eddy currents Under certain assumptions (uniform material, uniform magnetic field, no skin effect, etc.) the power lost due to eddy currents can be calculated from the following equations: For thin sheets: For thin wires: where: Bp - peak flux density (T), d - thickness of the sheet or diameter of the wire (m), - resistivity (m), D - penetration depth or skin depth (m). Therefore, the following things usually increase the size and effects of eddy currents: stronger magnetic fields - increases flux density B faster changing fields (due to faster relative speeds or otherwise) - increases the frequency f thicker materials - increases the thickness d lower resistivity materials (aluminium, copper, silver etc.) Some things reduce the effects weaker magnets - lower B slower changing fields (slower relative speeds) - lower f thinner materials - lower d slotted materials so that currents cannot circulate - reduced d or coefficient in the denominator (6, 12, etc.) laminated materials so that currents cannot circulate - reduced d higher resistance materials (silicon rich iron etc.) very fast changing fields - due to skin effect the above equations are not valid because the magnetic field does not penetrate the material uniformly. Applications Repulsive effects and levitation In a fast varying magnetic field the induced currents, in good conductors, particularly copper and aluminium, exhibit diamagnetic-like repulsion effects on the magnetic field, and hence on the magnet and can create repulsive effects and even stable levitation, albeit with reasonably high power dissipation due to the high currents this entails. They can thus be used to induce a magnetic field in aluminum cans, which allows them to be separated easily from other recyclables.
With a very strong handheld magnet, such as those made from neodymium, one can easily observe a very similar effect by rapidly sweeping the magnet over a coin with only a small separation. Depending on the strength of the magnet, identity of the coin, and separation between the magnet and coin, one may induce the coin to be pushed slightly ahead of the magnet - even if the coin contains no magnetic elements, such as the US penny. Superconductors allow perfect, lossless conduction, which creates perpetually circulating eddy currents that are equal and opposite to the external magnetic field, thus allowing magnetic levitation. For the same reason, the magnetic field inside a superconducting medium will be exactly zero, regardless of the external applied field. Identification of metals In coin operated vending machines, eddy currents are used to detect counterfeit coins, or slugs. The coin rolls past a stationary magnet, and eddy currents slow its speed. The strength of the eddy currents, and thus the amount of slowing, depends on the conductivity of the coin's metal. Slugs are slowed to a different degree than genuine coins, and this is used to send them into the rejection slot. Vibration | Position Sensing Eddy currents are used in certain types of proximity sensors to observe the vibration and position of rotating shafts within their bearings. This technology was originally pioneered in the 1930s by researchers at General Electric using vacuum tube circuitry. In the late 1950s, solid-state versions were developed by Donald E. Bently at Bently Nevada Corporation. These sensors are extremely sensitive to very small displacements making them well suited to observe the minute vibrations (on the order of several thousandths of an inch) in modern turbomachinery.
A typical proximity sensor used for vibration monitoring has a scale factor of 200 mV/mil. Widespread use of such sensors in turbomachinery has led to development of industry standards that prescribe their use and application. Examples of such standards are American Petroleum Institute (API) Standard 670 and ISO 7919. Electromagnetic braking Main article: Eddy current brake Eddy currents are used for braking at the end of some roller coasters. This mechanism has no mechanical wear and produces a very precise braking force. Typically, heavy copper plates extending from the car are moved between pairs of very strong permanent magnets. Electrical resistance within the plates causes a dragging effect analogous to friction, which dissipates the kinetic energy of the car. The same technique is used in electromagnetic brakes in railroad cars and to quickly stop the blades in power tools such as circular saws. Structural testing Eddy current techniques are commonly used for the nondestructive examination (NDE) and condition monitoring of a large variety of metallic structures, including heat exchanger tubes, aircraft fuselage, and aircraft structural components. Side effects Eddy currents are the root cause of the skin effect in conductors carrying AC current. Similarly, in magnetic materials of finite conductivity eddy currents cause the confinement of magnetic fields to only a couple skin depths of the surface of the material. This effect limits the flux linkage in inductors and transformers having magnetic cores.
Other applications Metal detectors Eddy current adjustable-speed drives Eddy-current testing Electric meters (Electromechanical Induction Meters) Eddy current brakes Induction heating Proximity sensor (Displacement sensors) Traffic detection systems Vending machines (detection of coins) Coating Thickness Measurements Sheet Resistance Measurement Eddy current separator for metal separation Mechanical speedometers Safety Hazard and defect detection applications Diffusion Equation The derivation of a useful equation for modeling the effect of eddy currents in a material starts with the differential, magnetostatic form of Ampre's Law, providing an expression for the magnetic field H surrounding a current density J, . The curl is taken on both sides of the equation, , and using a common vector calculus identity for the curl of the curl results in . From Gauss's law for magnetism, , which drops a term from the expression and gives . Using Ohm's law, , which relates current density J to electric field in terms of a material's conductivity , and assuming isotropic conductivity, the equation can be written as . The differential form of Faraday's law, , provides an equivalence for the change in magnetic flux B in place of the curl of the electric field, so that the equation can be simplified to . By definition, , where M is the magnetization of a material, and the diffusion equation finally appears as References ^ Seong-Soo Cho, Sang-Beom Kim, Joon-Young Soh, Sang-Ok Han, Effect of Tension Coating on Iron Loss at Frequencies Below 1 kHz in Thin-Gauged 3% Si-Fe Sheets, IEEE Transactions on Magnetics, Vol. 45, No. 10, October 2009, p. 4165-4168 ^ Hand-Held Instruments - eddy current test method ^ Measure Sheet Resistance of conductive thin coatings on non-conductive substrates (metallization/ wafers/ ITO / CVD / PVD ^ Eddy current separator ^ G. Bertotti, Hysteresis in Magnetism: For Physicists, Materials Scientists, and Engineers, San Diego: Academic Press, 1998. Fitzgerald, A. E.; Kingsley, Charles Jr. and Umans, Stephen D. (1983). Electric Machinery (4th ed. ed.). Mc-Graw-Hill, Inc.. pp. 20. ISBN 0-07-021145-0. Sears, Francis Weston; Zemansky, Mark W. (1955). University Physics (2nd ed. ed.). Reading, MA: Addison-Wesley. pp. 616618. Stoll, R. L. (1974). The analysis of eddy currents. Oxford University Press. Krawczyk, Andrzej; J. A. Tegopoulos. Numerical modelling of eddy currents. External links Eddy Currents and Lenz's Law (Audio slideshow from the National High Magnetic Field Laboratory)[[ta:sulal minottum ]] Categories: Waste treatment technology | Electrodynamics | Mechanical biological treatment
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