Showing papers on "Electromagnetic coil published in 1969"

Soft ferrites: properties and applications

Abstract: Ferrites - their nature, preparation and processing the expression of electrical and magnetic properties properties of some manganese zinc and nickel zinc ferrites magnetic circuit theory inductors high frequency inductors wide band transformers pulse transformers and inductors power transformers and inductors ferrite antennas properties of windings.

A Programmable Magnetic Field Mass Spectrometer with On-Line Data Processing

Abstract: A single focusing, 30.48 cm radius, 60° sector magnet mass spectrometer was constructed with symmetric conjugate foci calculated from fringe field data and corresponding to a beam deflection of 68°. Experimental and calculated optical characteristics agree well. A rotating coil probe and a rate coil are employed as field sensors for a nulling device and for field scanning. The magnetic field can be set to 27 values corresponding to the center of spectral lines and zero lines on both sides of each peak. The automatic scanning consists of: (1) rapid field change between adjacent field values (~500 G/sec); (2) locking in at the preset field values (~0.3 sec); (3) remaining in a channel for a preset time during which the ion beam current is integrated and the data digitized. Repeated arbitrary excursions between channels do not cause effective field variations of more than |DeltaB/B| = 2×10^–5. For 0.2 mm source and 0.64 mm collector slit settings, a typical peak at mass 88 is flat for 2.7 G to 0.01% at a 14 kV accelerating potential. Data consist of channel intensity, scale factors, and internally provided clock time; data signals drive a typewriter and tape punch. A cyclic scan of five isotopes including background requires 35 sec. A segment of data (~10 cycles) is processed by the computer and the results returned to the operator.

Device for Occlusion and Release of Natural or Artificially Constructed Ducts in the Human or Animal Body

Abstract: 1,174,814. Surgical occluding devices. R. D. GRUNERT. 10 Feb., 1967 [10 Feb., 1966; 23 June, 1966], No. 6579/67. Heading A5R. [Also in Division H2] A device for occluding and releasing a duct in the body comprises an occluding member to be implanted around the duct, and means for operating the occluding member either pneumatically, hydraulically, mechanically, or electrically, the device having an envelope of a material which is compatible with the environment of the body for implantation. As shown, the occluding clamp 1 is operated by an electric motor 19 through gears 21, 22 and a cable end spring arrangement 18, 25, and the clamp and motor together with a battery (26) (Figure 4, not shown) and magnetic switches (27, 28) may be implanted within the body and controlled remotely using magnets. In an alternative embodiment (Figure 1, not shown) the occluding member comprises inflatable jaws (2) operated by a bellows pump (5) which may be located under the skin, or in a modification (Figure 2, not shown), the inflatable jaws are operated by a rotary pump (11). In the embodiment shown, the electric motor 19 may be energized by currents induced in two implanted resonant circuits (Figure 5, not shown) by a coil (37) (Figure 6, not shown) located outside the body. The resonant circuits are arranged to selectively drive the motor in opposite directions.

Method and apparatus for locating a buried metallic line employing magnetic field gradient measurements

Abstract: A method and apparatus for locating a buried metallic line such as, for instance, a power line, telephone cable, water pipe, gas pipe, etc. without digging. An AC current is placed through the buried metallic line by direct connection or electromagnetic induction at a frequency of, for example, 100 kc., and the gradient of the magnetic field generated by the AC current is measured on a first and a second level above the ground surface. The lateral position on the ground surface where the metallic line is buried, is determined by the maximum reading of the magnetic field gradient when it is measured along the first level, while the depth of the buried metallic line may be obtained by comparing the magnetic field gradients measured on the first and second levels, respectively, at the detected position. The apparatus essentially comprises an AC signal generator to be connnected or coupled to the buried metallic line, at least one pair of differentially connected parallel coils, and means for measuring the voltage inducted in the coil pair. Since the field gradient is measured rather than the magnetic field, itself, any uniform magnetic field such as the field directly generated by the AC signal generator will not affect the positional information derived from the measurement, and thus the accuracy of the location of the buried metallic line is not adversely affected.

Magnetic separator and magnetic separation method

Abstract: A magnetic separation method and magnetic separator is disclosed including an enclosure within an electromagnetic coil surrounded by a ferromagnetic return frame including a first portion adjacent one side of the coil and covering the area enclosed by the coil and a second portion adjacent the other side of the coil and covering the area enclosed by the coil, and inlet and outlet means in the return frame for introducing and removing fluid from the enclosure.

Thermodynamic investigation of the helix-coil transitions of a polyribonucleotide system

Abstract: Some relative thermodynamic state functions of various types of structure which occur in the nucleic acid model system consisting of polyriboadenylic acid (poly A) and polyribouridylic acid (poly U) have been determined using the method of adiabatic calorimetry. Polymer concentrations have been calculated from the content of organic phosphorus of the components of the samples. The content of organic phosphorus has been determined by means of a chemical procedure following the method of Asmus and Baumert (1968). Since poly A is forming an intramolecular secondary structure in the temperature range covered by the calorimetric measurements, the measuyed transition enthalpies have been extrapolated to about 9 5 O , where poly A exists almost entirely in the randomly coiled state. This extrapolation yields the values AHo (A + U) = 9.3 f 0.5 kcal/mol of (A + U) for the helix-random coil transition of the helical duplex poly(A + U), and AHo(A + 2U) = 13.5 =k 0.5 kcal/mol of (A + 2U) for the dissociation of the three-stranded complex poly(A + 2U). The calorimetric procedure (measuring continuously the heat capacity of the polymer solution as a function of temperature) involves the experimental determination of the fraction of structural change. Therefore the thermal helix-coil transition of the double-stranded p01y(~k + U) has been analyzed in terms of current theoretical approaches. Following the calculation procedure of Applequist (1967), the stacking parameter introduced by Crothers and Zimm (1964) is found to have a value of about 400, which is considered to be representative for this doublestranded polyribonucleotide system. Additionally, numerical values of some (average) properties of poly(A + U) at the conversion temperature are given. Appropriate interpolation along measured transition enthalpies yields an approximate value of AHo(A) = 4.5 =t 2 kcal/mol of (A) for the transition of neutral poly A.

Skid control system

Abstract: A control system and force motor assembly for controlling the skidding of a vehicle under braked conditions when the control system provides a signal for controlling the position of an armature or fluid pressure controlling device in one of three conditions; the first condition being the ''''dump'''' mode of operation when the force motor is controlled to preclude braking pressure from being supplied to the wheels of the vehicle, the ''''hold'''' mode of operation when the braking force presented at the time the system goes into the ''''hold'''' mode of operation is maintained, and the ''''return'''' mode of operation when full applied braking pressure is returned to the vehicle wheels The control system is effectively responsive to a critical slip signal, the signal being generated in response to a sensed difference between a hypothetical vehicle deceleration, as approximated by a decreasing ramp signal, and the vehicle wheel speed This comparison is made on a differential basis to provide an output signal which is utilized in controlling an output gate The gate is also responsive to the sensing of a positive wheel acceleration signal and a change in sign of the rate of change of wheel acceleration The signal from the output gate is fed to an output logic circuit, the output logic circuit also being rendered responsive to the first derivative of the wheel velocity signal and a combination of first and second derivative of the wheel velocity signal The output signals are utilized in the output logic circuit to generate one of three signal conditions across the solenoid coil of the force motor actuator assembly In the return mode of operation, the polarity of the output signals generated across the solenoid coil are of the same polarity to cause zero current to flow through the solenoid coil In the dump mode of operation, the coil is provided with current flow in a first direction and in the hold mode of operation the solenoid coil is supplied with current flowing in a second direction opposite to the first direction The force motor is fabricated with a three positioned armature which is adapted to be placed either in the return or deactuated position, where no signals are provided from the control circuit; a dump mode of operation which connects the manually actuated brake cylinder hydraulically to the wheel cylinders to provide full braking pressure; and the hold position which maintains the pressure being fed to the wheels at the time the hold position is achieved

Nuclear magnetic resonance investigation of the helix in random coil transformation in poly-alpha-amino acids. I.

Abstract: High-resolution nuclear magnetic resonance spectra at 100 MHz and 220 MHz have been obtained on two samples of poly-L-alanine of differing molecular weights (2500 and 42 500) in the chloroform–trifluoroacetic acid system under various conditions of solvent composition, temperature, and polypeptide concentration. Separate helix and random coil peaks are observed for the α-CH and peptide NH backbone proton resonances, thereby permitting the determination of helix content. This observation of separate peaks demonstrates that the lifetimes of the helix and random coil portions of poly-L-alanine have lower limits of about 10−1 sec. It is suggested that solvent–peptide versus peptide–peptide hydrogen bond competition, coupled with a destabilizing effect of the trifluoroacetic acid on the helix, is responsible for the helix–random coil transformation.

Magnetic Field Uniformity around Near‐Helmholtz Coil Configurations

Abstract: The magnitude of the total magnetic field in the vicinity of a single round coil pair, a single square coil pair, and a trio of mutually orthogonal round coil pairs has been computer calculated, and the results graphically displayed as a series of contour lines. An investigation of the uniformity of field as a function of coil spacing indicates a distinct optimum near the Helmholtz spacing.

Magnetic suspension apparatus

Abstract: MAGNETIC SUSPENSION APPARATUS FOR SUSPENDING A MOVABLE BODY BETWEEN A PAIR OF ELECTROMAGNETS EXERTING RADIAL CENTERING FORCES AND OPPOSED AXIAL PULLING FORCES IN WHICH EACH ELECTROMAGNET COMPRISES AN INNER CYLINDRICAL PERMEABLE MEMBER AND AN OUTER CYLINDRICAL PERMEABLE MEMBER COAXIAL THEREWITH HAVING AN ELECTROMAGNET COIL SITUATED IN THE SPACE BETWEEN THESE TWO CYLINDRICAL MEMBERS.

Signal transmitting system for rotating apparatus

Abstract: This invention relates to a rotary transformer having both windings prewound in a flat rectangular skein for transmitting signals between the rotor and stator of a dynamoelectric machine. Suitably, one skein is wrapped flatwise around, and secured to, the rotor shaft with the second skein being fixedly secured to the stator in a concentric attitude relative to the first skein to permit rotary transformer action between the skeins. In a second disclosed embodiment both rectangular skeins are bent in an arcuate configuration about the rotor axis and are disposed in parallel planes at displaced locations along the axis of rotation. The two coils are designed such that they are coupled inductively at all times during rotation of the rotor.

Ducted refrigeration unit

Abstract: The invention relates to a ducted refrigeration unit for continuously supplying quantities of refrigerated air to a group of refrigerated food display cases. The unit has two chambers arranged in parallel with a cooling coil disposed in each chamber. A liquid refrigerant is selectively and alternately supplied to one coil during the time a hot defrosting gas is supplied to the other coil. Damper means alternately direct circulating air through the chamber in which the coil thereof is supplied with a liquid refrigerant while bypassing the chamber in which the coil thereof is being defrosted.

Collision force absorption device

Abstract: An energy absorbing member in the shape of a coil having a plurality of closely spaced loops, being capable of plastic deformation in one direction only, and being rigid in the opposite direction, said energy member being fixed at one end through a force receiving member to a vehicle accessory, such as a bumper, or a seat, and being fixed at the other end through a support member to the vehicle chassis.

Interaction of Capacitor‐Bank‐Produced Megagauss Magnetic Field with Small Single‐Turn Coil

Abstract: Experiments on the production of high magnetic fields in single‐turn coils by means of high‐voltage capacitor banks are described. Fields as high as 3.5 megagauss have been produced. Numerical analysis of the interaction of this field with the metal wall shows that magnetic diffusion and wall compression are the principal interaction phenomena. In addition, experimental and theoretical evidence are presented for the emission of a vapor cloud by the wall into the magnetic‐field volume. Finally, a simple approximate method for calculating the early time history of the magnetic field and coil motion is shown to give reasonable agreement with experiment.

Method and apparatus for forming shaped insulators and for developing coils of a magnetic core

Abstract: Method and apparatus for developing shaped insulators of different axial lengths and coil turns into coil groups in preselected slots of a magnetic core. The insulators are automatically formed into the desired lengths from a continuous strip of insulative material at an insulator-forming station by apparatus including a feeding mechanism, slotted magazine, cutter, and linkage having a movable pivot operative to effect a change in the length of material advanced into predetermined slots of the magazine. The magazine is mounted to telescope with an outer surface of an insulator and turn-accommodating mechanism or assembly into which the insulators are transferred. Turns are formed into coil groups in the assembly through the outer surface at a turn-forming station, and thereafter the coil groups and insulators are distributed into the preselected slots of the core from the assembly. Where two or more winding phases are to be distributed, the core may be conveniently mounted in a holding device carried by a conveyor which transports the core through a first phase-winding development, where the insulators and one winding are placed in the core, a winding pressback station where the winding is transformed into the desired configuration, and into a second phase-winding development where additional insulators and a winding are added to the core.

Bi-directional electromagnetic pick-up device for stringed musical instruments

Abstract: A PICKUP DEVICE FOR A STRINGED INSTRUMENT OR THE LIKE HAVING VIBRATABLE ELEMENTS, COMPRISING A COIL ADAPTED FOR CONNECTION TO A CURRENT AMPLIFIER AND MAGNETIC MEANS FOR GENERATING A BIDIRECTIONAL FLUX PATTERN HAVING ONE COMPONENT EXTENDING ESSENTIALLY LONGITUDINALLY OF THE ELEMENTS AND A SECOND COMPONENT ESSENTIALLY VERTICALLY OF THE ELEMENTS.

Heat exchanger with improved condensate disposal arrangement

Abstract: A plate-finned coil unit diverges upwardly from the drain pan at an angle of less than 45* in the direction of the airflow. The lower end of the coil terminates in the pan in close spaced relation to an end wall thereof. The pan has a top wall extending from that end wall toward the lower end of the coil. This arrangement provides a sump for the collection of condensate from the coil when the fan coil unit is installed in either the vertical or horizontal position.

Method of and apparatus for detecting the position of the end of a coil of steel strip

Abstract: A method of and an apparatus for detecting the position of the end of a coil of steel strip or other strip material which is to be paid out and setting the end of the coil at a predetermined position on the outer peripheral surface of the coil for initiating feeding of the steel strip to a rolling mill or other equipment. Support means mounting detection means is maintained in contact with the outer peripheral surface of the coil. The support means is adapted to operate in response to a variation in the outer diameter of the coil at the point of contact between the support means and the outer peripheral surface of the coil. The position of the end of the coil is detected by detecting a variation in the level of the outer peripheral surface of the coil or by detecting the action of the end portion of the coil to spring back by its own resilience as the end of the coil is moved past the detection means while the coil is rotated in a direction opposite to the paying out direction.

Electromagnetic prospecting apparatus for detecting electrically or magnetically responsive ore bodies

Abstract: Electromagnetic prospecting apparatus which may be used in an airplane for detecting electrically conductive buried ore bodies when they are intersected by a horizontal primary electromagnetic field. The prospecting apparatus includes a receiving, or pickup, coil and a reference coil, preferably orthogonal to the receiving coil, and apparatus for detecting real and quadrature components of voltages which are induced in the pickup coil due to the presence of vertical secondary field components which emanate from the buried ore bodies when they are intersected by the horizontal primary field. The detection is accomplished independent of the strength of the primary field or its frequency and is particularly adapted for prospecting with interrupted or frequency shifted types of primary fields.

Mechanical Strength of Transformer Windings under Short-Circuit Conditions

Abstract: For the past few years, the authors have studied the short-circuit strength of large transformer windings. In the course of the study, they have developed a new short-circuit testing method and have proved the method to be an effective means of finding the short-circuit strength of transformer windings. The new testing method and test results will be described in the following, together with a few observations.

Apparatus for monitoring and controlling the concentration of toner in a developer mix

Abstract: Samples of a developer mix, comprising toner and magnetic particles, are passed continuously through a coil connected in an oscillator circuit. The inductance of the coil changes with variations in the concentration of the toner in the samples of the developer mix, and, consequently, the circuit provides output signals that are related to the concentrations of toner in the samples. Means responsive to the output signals control the addition of replenisher toner to the developer mix as toner is consumed from the developer mix in a developing process.

Coil developing apparatus

Abstract: Apparatus for developing one or more coil groups of electrically conductive wire. The apparatus includes a coil turn-forming assembly having a jump form portion and a snap out form portion. The jump form portion includes a plurality of turn-gauging steps with an interruption formed at one side. The snap out form portion is supported adjacent to the interruptions on the turngauging steps and includes a corresponding number of snap out winding form plates, each having a fill-in winding section for spanning one of the associated interruptions on the jump form portion. The apparatus also includes a flyer for placing wire on the coil turn-forming assembly to generate turns and a jump means for locating a turn-gauging step of the jump form portion in the path of the wire being wound by the flyer. Concurrently, as the jump means locates a turn-gauging step in the path of the wire wound by the flyer, a snap out plate is extended to place a fill-in winding section in alignment with its associated interruption of a turn-gauging step. The turn-gauging step of the jump form portion and its associated fill-in winding section cooperate to provide a form for winding or generating turns of a predetermined length for receipt in a coil group accommodating means or device. Preferably, the coil group accommodating means is comprised of spaced curved blades defining turn receiving slots. The spaced curved blades and corresponding fill-in winding sections of the snap out plates have associated mating curved surfaces whereby, when a snap out plate is engaged with a curved blade, the entry of the turns of a coil being generated into the corresponding turn receiving slot is facilitated by the mating curved surfaces. Thus each coil is developed directly in the coil group accommodating means as the turns for the coil are generated about the coil turn-forming assembly. Also, the jump form portion and the snap out plates may be supported for movement in essentially a vertical direction, and the curved blades are supported in alignment with the snap-out plates so that the force of gravity facilitates the removal of the turns from the coil form assembly. Additionally at least part of the jump form portion is movable relative to the snap out portion during the turn-generating operation for selectively varying the lengths of successive turns. A coil group is developed in the coil group accommodating means by producing a plurality of serially connected wound coils of a coil group in the coil group accommodating means. Thereafter the coil group may be inserted directly from the coil group accommodating means into preselected slots of a stator core.

Controllable tip brush for medical use

Abstract: A flexible probe including a series of bristles at its extremity for exploring and collecting specimens from the labrynthine passages of internal organs is formed by attaching a series of bristles to the extremity of a tightly wound coil of fine wire, a section of wire coil near the bristles having adjacent turns whose cross sections are reduced at one side of the coil so that when the coil is put under tension by a core wire extending from one end to the other of the coil the extremity including the bristles will be turned in the direction of the reduced cross section, one element of a two-piece handle being attached to the other end of the coil, the other element of the handle being attached to the core wire and the two elements being in frictional engagement so that any degree of inclination of the bristles can be accomplished and maintained with one hand.

Helical coil vending machine

Abstract: Improved dispensing shelves for cabinet-type vending machines having a plurality of helical feeder coils for advancing articles interposed between the convolutions of the coils to a delivery opening. The articles are supported on sloping supports having a lower front edge terminating in a downward step immediately adjacent one side of a cooperating coil. Guide rails disposed from and adjacent the opposite side of cooperating coils maintain various sized article in engagement with the coils. Single coil driver mechanisms rotate individual coils on selective activation and additional double coil drive mechanism for discrete pairs of coils connected in tandem operate the paired coils in an alternating manner form a single activating signal.

Electric motor coil bandage

Abstract: An electric motor coil bandage has at least two or more independent coil legs of a rotor or a stator each having a face connection which includes a coil rod connected to the individual coil leg. A bandage extends around a plurality of sets of the coil rods of identical coils and a rubber elastic compressible cushion is disposed between adjacent rods and is adapted to glide relatively to the insulation surface of these rods.

Capacitor discharge ignition system with automatic spark advance

Abstract: Disclosed herein is a capacitor discharge ignition system which utilizes a magneto-type flywheel assembly with a permanent magnet located in the flywheel to induce a voltage pulse in a charge coil located on one leg of a U-shaped coil core to charge a capacitor and to induce a trigger pulse in a trigger coil to trigger a silicon controlled rectifier which thus becomes conducting and closes a circuit between the capacitor and the primary coil of a transformer for discharge of the capacitor. In the disclosed construction, the charging and triggering coils constitute portions of a single coil to advance the time at which the capacitor discharges and accordingly to fire the associated spark plug prior in time to the normal firing time in relation to engine crankshaft position, the coil core is provided with an extension or foot which extends circumferentially of the flywheel in the direction opposite flywheel rotation.

Linear motion electromechanical device utilizing nonlinear elements

Abstract: A linear motion electromagnetic device has a nonlinear spring to establish a spring force armature position characteristic proportionally opposite to a magnetic force armature position characteristic established by a permanent magnet. An electromagnetic coil is energized to control the position of the armature.

Antireverse trigger for an ignition system

Abstract: In an electrically triggered ignition system for two-cycle internal combustion engines, utilizing a trigger coil in which a trigger signal is produced by a flux-varying member carried by a rotating part of the engine, a second flux-varying member is provided on such rotating part which during reverse motion of the engine produces a trigger signal in the trigger coil which is so timed relative to the engine cycle that reverse engine operation cannot be sustained.

Method of manufacturing superconductive materials

Abstract: Superconductive materials are manufactured by providing a laminated material by combining a material of Nb, V or Mo metal, or alloy or intermetallic compound thereof and a material of Sn, Al, Zr, Ti, Pb, Ge, V, Si, Ga, C or Au element or alloy thereof, winding the laminated material tightly into a coil, covering the coiled body with a shielding layer composed of Nb, Ta or Zr metal or alloy thereof or stainless steel, inserting the coil covered with the shielding layer into a sheath composed of Cu, Al, Ag, Au or Cd metal, or alloy or intermetallic compound thereof or stainless steel, subjecting said sheath enclosing said coil and said shielding layer to a treatment for reducing a cross-sectional area of said coil and heat-treating thus treated coil. The laminated material may be inserted into the sheath together with a mechanically reinforcing material in order to improve the strength of the resulting superconductive materials.

Automatic ground fault circuit interrupter

Abstract: A power distribution system with automatic ground fault and overload protection is described. In series with the conductors of a powerline are placed current coils representing primary windings of a transformer connected in cancelling phase relation. The secondary windings of a transformer connected in cancelling phase relation. The secondary windings are energized by virtue of a predetermined reference current through one of the primary windings. The induced electromotive force due to reference current is cancelled by a ground fault leakage current. Switching means are actuated, effecting disconnection of the live conductor in accordance with excitation of the secondary windings.