barkenhausen effect scalar detector zpe bearden bifilar caduceus SCIENCE HOBBYIST | WEIRD DIY | GOOD STUFF | NEW STUFF | SEARCH Select LanguageAfrikaansAlbanianAmharicArabicArmenianAssameseAymaraAzerbaijaniBambaraBasqueBelarusianBengaliBhojpuriBosnianBulgarianCatalanCebuanoChichewaChinese (Simplified)Chinese (Traditional)CorsicanCroatianCzechDanishDhivehiDogriDutchEsperantoEstonianEweFilipinoFinnishFrenchFrisianGalicianGeorgianGermanGreekGuaraniGujaratiHaitian CreoleHausaHawaiianHebrewHindiHmongHungarianIcelandicIgboIlocanoIndonesianIrishItalianJapaneseJavaneseKannadaKazakhKhmerKinyarwandaKonkaniKoreanKrioKurdish (Kurmanji)Kurdish (Sorani)KyrgyzLaoLatinLatvianLingalaLithuanianLugandaLuxembourgishMacedonianMaithiliMalagasyMalayMalayalamMalteseMaoriMarathiMeiteilon (Manipuri)MizoMongolianMyanmar (Burmese)NepaliNorwegianOdia (Oriya)OromoPashtoPersianPolishPortuguesePunjabiQuechuaRomanianRussianSamoanSanskritScots GaelicSepediSerbianSesothoShonaSindhiSinhalaSlovakSlovenianSomaliSpanishSundaneseSwahiliSwedishTajikTamilTatarTeluguThaiTigrinyaTsongaTurkishTurkmenTwiUkrainianUrduUyghurUzbekVietnameseWelshXhosaYiddishYorubaZulu Powered by Translate ×search Notes on Scalar Detector Designs (c)1996 Robert Shannon Detector specifications Magnetostatic Detectors Electrostatic Detectors Barkhausen Detector Detector Schematic GIFs & JPEGs In this document we will describe the characteristics and specifications of several different scalar detector designs, and how the design philosophy and technology chosen affects those specifications. We will compare and consider these designs in ord er to establish a basic framework of specifications used to classify existing scalar detector designs, and suggest new modifications and original designs. We will discuss the Hodowanec "Gravity Wave Detector" circuit, and some suggested modifications, along with "Bedini's version" of the Dea/Faretto scalar detector, and compare these quite different designs, as well as an original detector design, the Barkhausen Effect Detector. Scalar detectors can be classified by the translation mode used, the bandwidth of the signal to which the detector will respond, and whether the response of the detector is linear with respect to the applied scalar signal or not. Some scalar detector s may also produce secondary scalar signals in their operation, so we may also classify detectors as being either passive or active detectors. All of these broad classifications, as well as other specifications such as relative sensitivity may vary in d ifferent detector designs. These criteria may be used to describe and compare different scalar detector designs. The translation mode by which the scalar signal is translated into an electromagnetic signal will largely determine the overall specifications of any detector design. This provides us with a convenient starting point for the analysis of the design o f any practical scalar detectors. When analyzing any new design for a scalar detector, the first step is to determine what translation mode or modes are being used by the device. We may classify a given detector as using either magnetostatic or electros tatic translation modes, or some combination of both. A reference design for a simple scalar pulse generator will also be presented so that each detector may be evaluated with a standard signal source. Suggested modifications will allow experimenters to produce a range of signals for comparative detector evaluation. Detector specifications : Translation Mode - There are several known modes of translation, that is, the exchange between electromagnetic waves and scalar potentials. In the context of detectors, we are most interested in translation by magnetic and electrostatic modulatio n. In the case of magnetic modulation, we may observe a scalar signal modulating a fixed magnetic field. In electrostatic modulation, we might observe alterations in the parameters of dielectrics in response to a scalar stimuli. We can classify the translation mode for detectors as being either ( E ), for electrostatic, ( M ) for magnetostatic, or ( B ) for both. This might be a bit confusing, as B is also used to represent the magnetic field in other co ntexts. Frequency and Bandwidth - We can express the frequency response of a scalar detector in the same manner used for an electromagnetic device. Some detectors may have a variable frequency over some specified range. In the table below we describe the range over which this type of design is practical, not the range of a single device of that type. Linearity - A linear detector produces a duplicate electromagnetic copy of an incident scalar signal, while nonlinear detectors produce a signal that is not proportional to the input stimuli. Active / Passive - Detectors that produce a scalar signal in the process of detecting an incident scalar signals are said to be active, while others that produce no internal scalar potential are passive. Sensitivity - Because no accepted standard units exist, and different detector designs may react to different degrees to a range of scalar stimuli, it is not possible to express the sensitivity of a given scalar detector design in simple units . Sensitivity may be evaluated by measuring the maximum distance a given stimuli can be detected. Because different detectors prefer differing types of signals, direct evaluation is only possible if we express sensitivity simply as excellent, good, fair, and poor. Detector design evaluation table : Detector Mode Freq & Bandwidth Lin Act/Pass Sens. "Bedini's Dea/Faretto" M VLF - UHF, variable. Y Passive. ? Barkhausen effect det. M 0-500 Khz. fixed. N Passive good. Hodowanec detector. E VLF, see text. N Passive. fair. Modified Hodowanec. E VLF - HF, fixed. Y Passive. fair. Neon detector. B VLF - UHF +, fixed. ? Active ? ? Magnetostatic Detectors : Of the detectors we will discuss, two share the same translation mode, magnetic modulation. Magnetic modulation is best studied in the Dea/Faretto detector. The Dea/Faretto detector discussed here is the device described by T.E. Bearden in his work "Fer-de Lance, a Briefing on Soviet Scalar Electromagnetic Weapons." The device described is labeled (slide #33 page 36) "Bedini's version of the Dea/Faretto detector." No original information published by Dea or Faretto on this device has been discovered as yet. The following discussion is restricted to "Bedini's version" of the device as described by Bearden. This detector consists of a powerful permanent magnet, in excess of forty thousand Gauss, placed within a Faraday cage. A coil is suspended above one pole of the magnet. This coil is tuned to resonance by a variable capacitor also placed within the cage. The coil and capacitor form a series resonant LC tank circuit. One lead of the coil is left open, the other runs to the capacitor. The remaining lead of the capacitor then runs to an amplifier. The output then runs through shielded cable into a standard receiver. In theory, an incident scalar wave will modulate the field of the permanent magnet. Because the magnet is shielded from electromagnetic radiation by the Faraday cage, the only source of an induced signal from the resonant circuit is from modulations of the magnetic field. As the incident scalar wave modulates the field of the magnet, the modulations of the magnetic field induce an electromagnetic copy of the scalar signal into the resonant circuit by induction. This detector therefore will detect modulations of the scalar magnetostatic potential, and can be described as a linear magnetostatic scalar detector. There is a reference made to the operation of this detector which implies that the detector may not detect a signal unless the ground reference of the detector is biased. Also scalar signals transmitted upon electromagnetic carriers may be demodulated by using the electromagnetic carrier to bias the ground reference. The use of a direct current bias, or an electrostatic charge may be sound. But extreme care must be used if the ground reference is changed dynamically by the carrier. It might prove impossible to prove that any signal detected was not coupled throu gh the ground circuit rather than induced by magnetic modulation. For this reason we cannot recommend such biasing. If the detector is biased in this manner, the bias power supply as well as the detector must now be placed into a larger shielded enclosure in order to eliminate any possible electromagnetic interference. One feature we must point out is that the frequency response and bandwidth of this form of detector is determined by the inductance and capacitance of the L C tank circuit. The inductive and capacitive reactance's determine the Q of the tank, and the refore the bandwidth. The center frequency of this bandwidth is the resonant frequency of the tank. If any tank component is variable, then the bandwidth or center frequency may be tuned over a range of frequencies. Although the Dea/Faretto detector has several desirable features, this form of detector is largely impractical, due to the difficulty of shielding a forty kilogauss field. This level of field intensity would saturate any practical shielding, and ther efore render it ineffective. The mass of the magnets alone, much less the shielding needed, makes this an impractical design. Because the Dea/Faretto design is the direct progenitor of the magnetostatic detector designs presented in this work, we will use it as a reference for comparison with the newer design presented here. Another detector based on magnetic modulation is the Barkhausen effect detector. This device was designed to use much smaller magnets and therefore need much less shielding. The Barkhausen effect detector does this at the cost of bandwidth and linearit y. In light of the extreme sensitivity and ease of construction of this design, the Barkhausen effect detector is an ideal first practical detector design that a researcher should reproduce. In the Barkhausen effect detector, we use a much more sensitive method of detecting the minute modulations in the field of a permanent magnet than in the Dea/Faretto design. The Barkhausen effect is defined in standard physics textbooks as a highly n on-linear change in the magnetization of a material in response to a change in magnetic flux density. Accordingly, a small change in magnetic flux may cause a large change in the magnetization of some materials. It is this rather obscure magnetic effect that is used to reduce the magnetic field intensity needed, and therefore the shielding as well. By using a magnetic bias to produce a level of magnetization which places a magnetic material into the most non -linear region of its magnetization curve, it becomes much more sensitive to any external forces. Once in this condition, changes in the magnetic field too small to induce a detectable signal in a Dea/Faretto detector will result in detectable signals fr om a Barkhausen effect device. The bandwidth of the Dea/Faretto detector is a function of the L C tank circuit in the detector itself. Bandwidth in the Barkhausen effect detector is a function of the pickup coil and the magnetic core material used. In most cases the bandwidth of a Barkhausen effect detector is from zero to about five hundred kilocycles. Unlike the Dea/Faretto detector, the Barkhausen effect detector is not readily tunable, and it would therefore be impractical to attempt direct spectrum analysis with this des ign. The LC tank in the Dea/Faretto detector is linear in its response to an input signal at the resonant frequency of the tank. The magnetization curve of the polycrystalline silicon steel used in the core of the Barkhausen effect detector's coil is highly non-linear to changes in the magnetic flux density. The Barkhausen effect detector is therefore classified as a passive non-linear magnetostatic scalar detector. To understand the operation of the Barkhausen effect detector we will conduct a Gedanken (imaginary) experiment. If we place a strip of silicon steel inside a large coil of several thousand turns, and amplify the output of this coil and feed it to a speaker, there will be a burst of static heard as a permanent magnet is moved near the strip of silicon steel. No matter how slowly and smoothly the magnet is moved, the speaker will respond with distinct clicks. Even the smallest changes in magnetization of the steel strip will result in discrete detectable pulses. What is happening here is that small changes in magnetic field intensity are producing large non-linear changes in the magnetization of the steel strip. These large abrupt changes in the magnetization of the steel induce a current into the coil, which we hear as a click. Larger changes in magnetic fields intensity produce bursts of clicks, or "static". With this nonlinear response, it is possible to detect changes in magnetization that could not be detected by induction as in the Dea /Faretto design. By using this effect to listen to the intensity of a permanent magnet which has been shielded from external electromagnetic fields, any changes in the field strength must be produced by some external force which is capable of modulating the magnetos tatic scalar potential of the matter which makes up the magnet, or the space that the magnet is in. Properly constructed Barkhausen effect detectors produce signals with thousands of pulses per second from scalar background noise alone. Any artificial signals detected can be clearly identified against this background with an oscilloscope or comparator. Digital analysis of the output of Barkhausen effect detectors may provide a good deal of information of the original incident signal. Barkhausen effect detectors are in fact just a modification of the Dea/Faretto detector, with a more sensitive pickup coil. The amplitude of the signals produced by either the Dea/Faretto or Barkhausen effect detectors are in the low microvolt range, and therefore it is necessary to use amplifiers. Great care must be used in selecting and building these amplifiers, as the high gain circuits are susceptible to thermal noise in the transistors, feedback, and microphonics. It is important to remember that the Barkhausen effect is not the translation mode. The translation mode in the Barkhausen effect detector is still magnetic modulation. We simply use the Barkhausen effect to detect small changes in the field of a permanent magnet which is shielded from external electromagnetic radiation. Electrostatic Detectors : As in the case of magnetostatic detectors, we begin by examining an existing design. Perhaps the most well known electrostatic detector designs were published by Greg Hodowanec as gravitational wave detectors. These devices were published in a popular electronics magazine, and construction plans may also be found in the KeelyNet files as well. There have been a number of extraordinary claims made concerning this particular design. Here we will study only the detailed operation of these devices. What these devices actually do is left as an exercise for the reader. As described these devices consist of a capacitor connected across the inputs of an operational amplifier. Any signals detected are then passed to a buffer amplifier. A variable resistor is placed into the feedback loop of the current to voltage converter, and is claimed to "tune" the device. There is also a switch that will place a small amount of capacitance in parallel with the feedback resistance. This switch is referred to as being in the "quantum non-demolition mode" while open. As presented this device has several good points, as well as some flaws. Some of these flaws are quite minor, other are not. We will use this design as our benchmark in our analysis of electrostatic detectors just as we used the Dea/Faretto design in our study of magnetostatic detectors. The first amplifier in this design is configured in a mode known as a current to voltage converter. With the detecting capacitor connected between the inverting input and ground, this configuration places a virtual short circuit across the detecting device. Any other practical approach, such as placing a load resistance across the detecting capacitor would form an R C time constant and adversely load the detecting device. As contrary as this may seem, there are several types of conventional sensors that will not produce accurate measurements unless shorted in this manner. In any operational amplifier design the gain and bandwidth of any given amplifier configuration is determined by the amount of negative feedback. Negative feedback is moderated by the feedback resistance from output to inverting input of the amplifier. In the Hodowanec design any "tuning" effect made by changing the variable resistance in the feedback loop is actually changing the gain and bandwidth of the amplifier. This is very different from the tunability of any of the magnetostatic devices presented. It is also claimed that the value of the capacitor used as the detecting element may be altered to "tune" this design to different frequencies. Due to the circuit configuration in the published designs, this claim is suspicious, and the bandwidth and frequency response of the circuit is limited by other factors. With the component values given for this device, and the operational amplifier integrated circuit specified, the bandwidth of this design will be only a few tens of Hertz. Above this, the frequency response will begin to fall of at 20dB per decade. Changing the feedback resistance between 500 kilo ohms and one megohm will not result in much of a change in gain or frequency response for the device specified. Even with the gain reduced the chip specified is only capable of ten kilohertz or so of linear frequency response, and the common mode noise rejection ratio begins to falls off at around 100 Hertz. In short this is one of the last operational amplifiers to choose for use in a scalar detector application. At the gain levels used, circuit noise alone will hide the most interesting of signals. By switching to a low noise device such as the TL082 or LF353 amplifiers we reduce the input noise current to the fractional picoampere range. The gain bandwidth may now reach up to three megahertz. To achieve this level of performance we must use much more negative feedback in each amplifier. The tradeoff for this is reduced gain per amplifier stage, but amplifiers are cheap. By using multiple amplifying stages, each with higher bandwidth, we can get the same total level of gain as in the original design, and preserve the low noise and wide bandwidth of modern operational amplifier chips. In short, by redesigning the original Hodowanec circuit with higher performance operational amplifiers, with lower gain per stage, and equal or higher total system gain due to more stages of amplification, we may produce a different electrostatic detector that will produce a "cleaner" signal, as the original Hodowanec circuit is close to self oscillation, evidenced by the "ringing" nature of it's output. A direct comparison of the original Hodowanec device and the improved electrostatic detector will show that the majority of the output of the original design was due to the implementation of the original rather than due to the nature of the detected signals. We would therefore have to classify the original Hodowanec circuit as being nonlinear. By redesigning the Hodowanec detector as suggested, it is possible to construct a far more sensitive electrostatic detector with far superior performance in some aspects. By comparing the signals from the original and the modified versions, we can see what role the borderline self oscillation of the original circuit plays in its operation. This observation might be applied to the creation of completely new detector designs by the application of regenerative and super-regenerative d… truncated (23,162 more characters in archive)