Showing papers on "Inductor published in 1968"

Synthesis of new nonlinear network elements

Abstract: The basic problem of synthesizing a nonlinear resistor, inductor, or capacitor with a prescribed i-v, φ-i, or q-v curve is solved by introducing three new linear two-port network elements, namely the mutator, the reflector, and the scalor. The mutator has the property that a nonlinear resistor is transformed into a nonlinear inductor, or a nonlinear capacitor, upon connecting this resistor across port two of an appropriate mutator. The reflector has the property that a given i-v, φ-i, or q-v curve can be reflected about an arbitrary straight line through the origin. The scalor is characterized by the property that any i-v, φ-i, or q-v curve can be compressed or expanded along a horizontal direction, or along a vertical direction. Using these new elements as building blocks, it is shown that any prescribed single-valued (which need not be monotonic) i-v, φ-i, or q-v curve can be synthesized. Active circuit realizations for each of these new elements are given. Laboratory models of mutators, reflectors, and scalors have been built using discrete components. Oscilloscope tracings of typical mutated, reflected, and scaled i-v, φ-i, and q-v curves are given. The experimental results are in good agreement with theory at relatively low operating frequencies. The practical problems that remain to be solved are the stability and frequency limitation of the present circuits.

Hybrid integrated lumped-element microwave amplifiers

Abstract: This paper describes the development of microwave lumped-element thin-film amplifiers. The basic design philosophy underlying lumped inductors and capacitors at microwave frequencies is reviewed, showing how Q's of 100 are achieved. A variety of tunable input, output, and interstage integrated lumped-element networks for transistor amplifiers were fabricated. The gain and efficiency of 2-GHz class-C operated transistors mounted in these circuits were comparable with the best performance achieved by the same transistors in less lossy coaxial circuits. The measured losses (1.2 dB) at 2 GHz were very close to those calculated using the design parameters. Single-stage amplifiers at 2 GHz achieved one watt of output power with 4 dB of gain. At somewhat lower power levels more than 6 dB of gain was achieved. The circuits allowed the operation of low-power level class-A amplifiers with over 13 dB of gain. Cascaded operation yielded more than 17 dB of gain with 0.8 watts of CW power. It is concluded that lumped elements can be fabricated by thin-film technology and will play an important role in microwave integrated circuits.

Comparative analysis of chopper voltage regulators with LC filter

Abstract: The chopper voltage regulators using a diode and an LC filter for output rectification and filtering are widely used in dc-to-dc conversion. Three possible configurations are 1) a series connection of the filter choke and switch with the load, 2) a series connection of the choke and the parallel connection of the switch with the load, and 3) a series connection of a chopper and the parallel connection of a choke with the load. Static characteristics of the regulators vary considerably among the aforementioned circuits. The output-to-input voltage ratios and the output characteristics of the circuits listed above are defined in the continuous and discontinuous current domains. An estimate and a comparison of the regulator performances are given.

Solid-state constant power ballast for electric discharge device

Abstract: 1,255,043. Supply systems for discharge lamps. WESTINGHOUSE ELECTRIC CORP. 9 April, 1969 [29 April, 1968], No. 18136/69. Heading H2H. [Also in Division G3] The current through a discharge lamp 10 is maintained at a desired average value by alternately supplying the lamp from a D.C. source 11 until the current reaches a predetermined value and then using the energy stored in an inductor 14 to pass current through the lamp (via a diode 18) for a predetermined fixed time, these alternate cycles producing a triangular shaped current waveform giving the desired average current, Fig. 2 (not shown). The lamp current is detected by a resistor R1 whose output signal is used to control a Schmitt trigger circuit formed by transistors Q2, Q3 and determining the ON/OFF times of a switching transistor Q1 controlling the supply to members 10, 14. During warm-up of the lamp, these ON/OFF times are controlled by a current peak detecting circuit R2, R4, D2, C1 which causes the control circuit to operate in a variable pulse-frequency mode. When steady-state lamp operation has been reached the voltage developed across a capacitor C2 is increased to exceed that across capacitor C1 and cause control to pass to an average-current-detecting circuit R10, R11, D6, C2, which thereafter operates the transistor Q1 at a fixed mark/space ratio corresponding to the desired average current. This current is automatically varied, to maintain constant power with supply voltage variations, by a network R12, R13, C3, D5 which controls the Schmitt trigger circuit to vary the mark/space ratio of transistor Q1 in accordance with supply voltage variations as sensed by the capacitor C3. The described control circuit also automatically compensates for variation of the lamp voltage with ageing to maintain constant lamp power, the theoretical basis of this aspect of the invention being discussed. Operation of the circuit on an A.C. supply is envisaged together with various modifications such as replacing resistor R1 by an impedance or a current transformer and obtaining the predetermined OFF time of transistor Q1 by time delay means other than the circuit C2, R11.

Variable impedance switching regulator

Abstract: A DC step-up voltage regulator with a series arrangement of a raw DC source and an energy storing inductor which are alternately connected to a low impedance circuit to build up the inductor current and to an output circuit which includes a capacitor which is charged by the current flow from the inductor. A control circuit varies the amount of inductor current buildup needed to hold the output voltage constant and also provides periodic and constant time intervals of sufficient duration to discharge the inductor current into the capacitor.

Near Resonant Coupling on EHV Circuits: II - Methods of Analysis

Abstract: Shunt reactor compensation on multicircuit untransposed overhead transmission lines may interact with the intracircuit and line-to-ground capacitances of the lines to produce severe near- resonant coupled voltages on a de-energized circuit.

Control apparatus for electric automotive vehicles

Abstract: 1,267,421. Control of D.C. motors. GULTON INDUSTRIES Inc. 8 April, 1969 [5 April, 1968], No. 17842/69. Heading H2J. In a battery powered vehicle, regenerative braking down to a low speed is facilitated by a voltage boosting circuit 33 connected to the motor 4, and a shunt field 4C is connected, for braking, to the otherwise series-wound motor. The boosting circuit comprises an inductor 35 connected between the positive armature terminal and the battery via a diode 40 and switched periodically by thyristors 43, 44 and 47, 48 with a commutating capacitor 41. The thyristors are fired in alternate pairs by a circuit 45 which comprises a relaxation oscillator and bi-stable circuit (Fig. 3, not shown), the frequency of the oscillator and hence the amount of braking being adjustedby a brake pedal controlled rheostat 26. In an alternative arrangement (Fig. 6, not shown) the average current through the inductor is kept constant for a given pedal setting by an operational amplifier which adjusts the frequency of the oscillator according to the volt-drop across a resistor in series with the inductor. The brake pedal also controls a rheostat 29 in the shunt field circuit and a mechanical brake 22 through a lost-motion link so that it is effective only in the final stage of braking. Change-over from driving to braking is effected by a relay K1 energized by first movement of the brake pedal. The speed of the motor during driving is controlled by a thyristor 6 having a turn off circuit 10 which comprises two pairs of auxiliary thyristors and a commutating capacitor (Fig. 4, not shown) which are fired in alternate pairs by a square-wave generator. Triggering pulses for 6 are produced by a relaxation oscillator and unijunction circuit whose operation is synchronized with the square wave generator, the firing instant and hence pulse width being controlled by an accelerator operated rheostat in the oscillator circuit. Some shunt field current is provided through resistor 5 to prevent runaway on no load.

Electrotherapeutic apparatus and treatment head and method for tuning said treatment head

Abstract: An electrotherapeutic apparatus is disclosed wherein diamondshaped pulses of electromagnetic energy are produced by a pulse generator and applied to a treatment head which radiates the pulsed energy to a given load. A power amplification output stage of the pulse generator includes a tunable tank circuit. A detector is provided to determine whether the tank circuit is in its resonant state, the detector being transformer coupled to the tank circuit whereby the minimum current flowing through the detector corresponds to the resonant state of the tank circuit. Connected in series with the detector is a resistor network which permits the detector reading to be on-scale for each amplitude adjustment of the diamond-shaped pulses. Included within the treatment head is a further tunable tank circuit which comprises a tunable capacitor and an inductor, several embodiments of which are disclosed. The pulsed energy from pulse generator is transformer coupled to the tunable tank circuit of the treatment head, the primary winding of the treatment head transformer also being disclosed in several embodiments. Methods for tuning the electrotherapeutic apparatus with an artificial load which simulates a patient or the like and for establishing the artificial load are also disclosed.

Comparison of Computer and Test Results of a Static AC Drive System

Abstract: The effectiveness of an analog computer (electronic differential analyzer) in studying the performance of a rectifier-inverter-induction motor drive system is demonstrated. Computer diagrams are not given. However, methods of simulating the system components sufficient to describe their dynamic and steady-state behavior are described and references cited. Computer recordings are compared with results obtained from a prototype of an actual drive system. In particular, computer and test results showing the six-phase rectifier output voltage, filter inductor current, filter capacitor voltage, inverter current, as well as the stator voltage and current of the induction motor are compared. The facility of the analog computer in predicting the behavior of a large involved drive system is demonstrated.

Broad-band high-frequency low-pass filters

Abstract: Broad-band high-frequency low-pass filters formed with capacitors which have structures including multilayer and ceramic types and monolayer capacitors. A passive element such as magnetic cores are contained wholly or partially within the capacitor structure. The filter units which may themselves form complete PI filters or L filters may also be combined as the inside portion of a tubular multilayer ceramic capacitor. Rolled capacitors may be used for distributed inductance and magnetic cores in combination with wound inductors or individually may be formed as portions of the filters.

Electron beam deflection and high voltage generation circuit

Abstract: 1,260,375. Cathode-ray tube deflection circuits. R.C.A. CORPORATION. 11 April, 1969 [15 April, 1968], No. 18631/69. Heading H3T. [Also in Division H2] In a deflection circuit for a cathode-ray tube, a first bi-directional switching means 24 is arranged to be conductive during the forward stroke so as to connect deflection coil 22 across an energy supply device 23 and a second switching means 46 arranged to become conductive towards the end of the forward stroke, the switching means 24, 36 being coupled via a T- network comprising capacitors 29, 30 and inductor 28. As described, diode 26 is arranged to be conductive at the beginning of each trace so that a deflection current is driven by the large capacitor 23 through the deflection coils 22. Soon after the beginning of each forward stroke, a pulse is induced in winding 31 and fed to the gate of thyristor 25 so that the anode/cathode path becomes conductive when the deflection current passes through zero midway through each forward stroke 8 As before the end of each forward stroke, thyristor 37 is turned on by a pulse from the horizontal oscillator 19 so that energy which has been stored into capacitors 29 and 30 is circulated resonantly via circuits including components 24, 29, 28, 36 and 36, 28, 30. This provides a reverse current in thyristor 25 so that after the stored carriers have been dissipated, thyristor 25 becomes turned off, terminating the forward stroke. The resonant current now continues via diode 26 until a further reversal occurs when that diode is also turned off. Energy is thus returned to capacitor 23. Further current reversal similarly turns off thyristor 37 and (later) diode 38 so that a further forward stroke can start. The flyback pulses induced in transformer 43 (tuned to approximately the third harmonic of the flyback frequency) are rectified at 44 to provide E.H.T. for the cathode-ray tube. Circuits 46 ... 50 protect the circuit against E.H.T. flash-over. Capacitor 30 is arranged to resonate with its associated inductance at twice the flyback frequency. Stabilizing image width.-The exchange of energy between transformer 43 and the rest of the circuit is arranged so that, following variation in cathode-ray tube current, the corresponding change in deflection current is approximately one half the change in E.H.T. voltage so that the image width remains constant.

Closed loop parametric voltage regulator

Abstract: A parametric voltage regulator in which the inductance component of the resonant circuit of a parametric device is varied in response to changes in the output voltage, caused for example by changes in line frequency, to maintain the output voltage constant. The inductance is preferably changed by providing an external flux generator on the core of the parametric device to vary the reluctance of a part of the core, but can also be accomplished by the use of a separate inductor in the resonant circuit.

Frequency Conversion in the Sheath Capacitance of a Glow Discharge Plasma

Abstract: A study is made of large‐signal, high‐frequency phenomena occurring in a slightly ionized plasma contained within a pair of metallic coaxial cylinders. An rf equivalent circuit is developed wherein the sheath is represented by a voltage‐dependent capacitor in parallel with a voltage‐dependent resistor, the presheath by a series resistor, and the plasma region by a series resistor and inductor. It is found that when the sheath is thin compared to the radius of the inner cylinder, the voltage dependence of the sheath capacitor reduces to a form identical with that of an abrupt junction varactor diode, so that the plasma capacitor is properly called a plasma varactor. As an application of the plasma varactor, frequency doubling using standard semi‐conductor varactor techniques is attempted. The resultant peak conversion efficiency is found to be 31.6% at a drive frequency of 142 MHz and input power of 0.42 W. It is shown that the sheath conductance is responsible for this low conversion efficiency relative to that obtainable from a semiconductor varactor.

Starting and operating circuit for gas discharge lamps

Abstract: A starting and operating circuit for a gas discharge lamp is disclosed as comprising a vacuum switch adapted to be connected across a gas discharge lamp, a unidirectional conductor adapted to be connected across a direct current source, and an inductor, the vacuum switch, unidirectional conductor and inductor being connected in series circuit.

Velocity indication device with zero speed detection capability

Abstract: THIS INVENTION RELATES TO A PULSE GENERATOR FOR PRODUCING ELECTRICAL PULSES WHERE A ROTOR, POSSESSING FLUX DISTRIBUTION QUALITIES SUCH THAT THERE EXISTS AT LEAST ONE REGION OF HIGH FLUX DENSITY SOURROUNDED BY REGIONS OF LOW FLUX DENSITY WHEN IN THE PRESENCE OF A MAGNETIC FIELD, IS ROTATED IN THE VICINITY OF AN INDUCTOR MEANS. THE ROTOR INCLUDES AT LEAST ONE MAGNETIC MEANS WHICH DEFINES ONE OF THE REGIONS OF HIGH FLUX DENSITY. THE INDUCTOR MEANS HAS INPUT AN OUTPUT TERMINALS. A SIGNAL IS IMPRESSED ON THE INPUT TERMINALS. UPON ROTOR ROTATION, ELECTRICAL PULSES APPEAR AT THE OUTPUT TERMINALS OF THE INDUCTOR MEANS. AN OUTPUT SIGNAL FOR ANY ROTATIONAL SPEED IS ATTAINED WHEN THE INDUCTOR MEANS IS A SATURABLE INDUCTOR. THE PULSE GENERATOR IS EXTREMELY COMPACT, SIMPLE IN MECHANICAL LAYOUT, AND HAS HIGH RESOLUTION PROPERTIES.

Isolated-Phase Bus Enclosure Currents

Abstract: In the continuous-enclosure type isolated-phase bus, the enclosure current in amperes is very nearly equal to the conductor current. It lags the conductor current by somewhat less than 180°. The external flux is relatively small, and any induction heating in material or induced volts in instrument or control circuits adjacent to the bus will be negligible. Methods for determining the actual current in the enclosure and the external magnetic field are developed in this paper.

Electrical circuits for simulating inductor networks

Abstract: An electric circuit, for example an active filter circuit, in which inductors are simulated by means of positive immitance converter circuits terminated by resistors. One positive immittance converter circuit is provided for each external ungrounded node of the inductor network, and the terminating resistors are arranged to have the same topology as the inductor network.

Resonance-type inductance or capacitance meter

Abstract: An electronic instrument measures properties of inductors by connecting the unknown inductor in an oscillating feedback loop and measuring the frequency of oscillation by means of a pulseaveraging discriminator. Feedback amplifiers are switched to measure inductance and self-oscillation frequency separately. Readout is by means of analogue indicating instruments. A unique control circuit maintains the amplitude of the AC oscillation voltage across the unknown inductor at a constant low value, independently of the inductor''s parameters, and permits the use of large shunt capacitors to minimize errors due to the selfcapacitance of the inductor.

Electrical control systems for the drive motor of an industrial truck

Abstract: 1,193,871. Control of D.C. motors. EATON YALE & TOWNE Inc. 4 Jan., 1968 [19 Jan., 1967], No. 2894/67. Heading H2J. A motor 14 which drives an industrial truck is provided with pulses of constant width, the speed of the motor being controlled by varying the time between the pulses. The width of the pulses is reduced automatically for restricting the motor torque during plugging. Before one pair of the field-reversing contactors 18, 19, is closed, there is no charge on capacitor 45 so that transistors 41, T3, 49, are conductive to supply gate current to rectifier 25 which does not conduct at this stage. As soon as the contactors close, capacitor 24 is charged, and capacitor 45 is charged to switch-off transistors 41, T3, 49, the rectifier 25 receiving gatecurrent through resistor 29. When the voltage across capacitor 54 exceeds a predetermined value, transistors 55, 56, conduct to render transistors 58, 61, conductive. A microswitch 65 closes when the throttle pedal is depressed beyond a certain amount so that rectifier 26 is switched-on. At the same time, the rectifier 27 is switched-on by means of the transistor 64. As soon as the rectifier 26 conducts, the capacitor 54 discharges to interrupt the gate-current to the rectifiers 26, 27, but before this current ceases, the motor is supplied through rectifier 26. Capacitor 24 discharges through rectifier 26, inductor 28, and rectifier 27. After the gatecurrents have stopped, the motor continues to be energized through the rectifier 26, and the capacitor 24 continues to transfer its charge until the rectifier 27 becomes non-conductive, the capacitor being left with a reverse charge. When the rectifier 26 conducts, capacitor 45 discharges and, after a fixed period, the transistor 41 conducts to apply a pulse to the gate of the rectifier 25. Capacitor 24 discharges to switch-off the rectifier 26, the capacitor recharging through the rectifier 25 whereby the cycle continues as before. The speed of the motor is varied by adjusting the time taken by the capacitor 54 to charge sufficiently to switch-on the transistor 55. When the throttle pedal is not depressed, potentiometer 77 is adjusted so that the collector voltage of transistor 73 is at a maximum value, the transistors 84, 87, being both off and the charging current of the capacitor 54 being limited by resistor 53. As the pedal is depressed, the capacitor 54 is additionally charged through the transistor 87 to increase the speed of the motor. Capacitor 75 controls the rate of acceleration. When the pedal is fully depressed, diode 82 conducts to increase the base current of transistor 73, so decreasing the charging-time of capacitor 75 to permit a greater rate of acceleration. A switch 83 is closed when a brake pedal is depressed to reduce the speed irrespective of the position of the throttle pedal. When the truck is plugged, diode D1 becomes reverse-biased and transistor T1 conducts whereby transistor T2 short-circuits the capacitor 75. The collector voltage of the transistor 73 is now such as to reduce the motor power to a low value by increasing the period between pulses. Release of the throttle pedal closes switch S1 and transistor T4 is turned-on to short-circuit the resistor 39. The transistor 41 is switched-on by discharge of the capacitor 45 at an earlier instant so that the pulse width is reduced.

Summary of electrical component development for a 400-hertz Brayton energy conversion system

Abstract: Design, fabrication, and testing of 12-kilowatt inductor alternator, voltage regulator-exciter, and parasitic loading speed controller - summary

Hybrid Integrated Lumped-Element Microwave Amplifiers

Abstract: This paper describes the development of microwave lumped-element thin-film amplifiers.The basic design philosophy underlying lumped inductors and capacitors at microwave frequencies is reviewed, showing how Q's of 100 are achieved. A variety of tunable input, output, and interstage integrated lumped-element networks for transistor amplifiers were fabricated.The gain and efficiency of 2-GHz class-C operated transistors mounted in these circuits were comparable with the best performance achieved by the same transistors in less lossy coaxial circuits. The measured losses (1.2 dB) at 2 GHz were very close to those calculated using the design parameters. Single-stage amplifiers at 2 GHz achieved one watt of output power with 4 dB of gain. At somewhat lower power levels more than 6 dB of gain was achieved. The circuits allowed the operation of low-power level class-A amplifiers with over 13 dB of gain. Cascaded operation yielded more than 17 dB of gain with 0.8 watts of CW power. It is concluded that lumped elements can be fabricated by thin-fihn technology and will play an important role in microwave integrated circuits.

Absorptive Lines as RFI Filters

Abstract: A new class of ?distributed constant? filters has been recently developed using the normal propagation path of the electrical current in a wire, a cable, or a line to suppress interference. The three basic characteristics are the following: 1) Instead of using lumped reactive components (inductors, capacitors) connected to the wire, one superposes the suppressive effect to the normal straight and flexible conductor without any additional components. 2) The problem of mismatch at the interfaces with the generator and with the load (for example, a classical ? filter connected to a reactive load) is nonexistent, because the suppression is due to an absorption of the critical frequency components. The Q factor of such a line is substantially equal or less than unity in the frequency range considered. 3) In the case of nonsheathed cables (general case), if the suppression of the conducted interference is sufficiently high along the line (for example, a 20-dB attenuation is obtained for a linelength equal to a tenth of the wavelength at the considered frequency), radiation and induction of parasitic frequencies is automatically suppressed. The necessary absorption can be introduced on the cable or the line by using separately or together three different physical effects: 1) Absorption due to magnetic and dielectric losses. These losses are achieved by the use of special products, like magnetic ferrites with high Fe and Zn content, semiconductive and ferroelectric dielectrics, and with bulk or synthesized dispersive effects.

Method for improving the torsional fatigue strength of crankshafts

Abstract: 1,219,364. Induction heating. AEG-ELOTHERM G.m.b.H. 13 Feb., 1968 [6 Oct., 1967], No. 7137/68. Heading H5H. [Also in Division C7] A crankshaft having an oil-hole in a main bearing portion or in a crankpin is given improved torsional fatigue properties by induction hardening the relevant portion of the shaft so that a hardened surface layer is produced which increases in depth towards the oil hole. The depth may be such that the internal surface of the oil-hole is hardened along its entire length, or only along a part thereof. Apparatus consists of two inductors, one of which produces a heated zone extending over a part only of the surface to be hardened while the other heats the whole of that surface, and means for successively energizing the two inductors. As illustrated, inductor 7 is first energized for a period t 1 while the shaft 6 is rotating, and inductor 8 is then energized, preferably at a higher frequency, for a period t 2 . Finally the shaft is quenched by liquid or gas. The two inductors may be contained in the same easing, and may be independently controllable as to time frequency and current.

Method and apparatus for resistance welding

Abstract: 1,234,228. Welding by pressure. CONTINENTAL CAN CO. Inc. 1 Jan., 1969 [28 Feb., 1968], No. 136/69. Heading B3R. [Also in Division H2] In electrical resistance welding an alternating current is supplied to the electrodes in contact with the work, of such a frequency that the reactance of the welding current circuit including the electrodes and the work is higher than the resistance of the circuit. An apparatus for making metal blanks 11 into tubular cam bodies comprises a horn 12 and advance means 13 for moving the blanks 11 along the horn and an apparatus 14 for forming the blanks into tubular shape encircling the horn with overlapping edges. Roller electrodes 18, 24 are provided to contact between them the edges to be welded, although sliding or shoe electrodes may be used. The roller is mounted on a fluid piston/cylinder device 30, 31 so that the roller 24 is pressed tightly to sandwich the edges to be welded. Alternating current is supplied from a generator 35 including a step down transformer to the electrodes 18, 24 and a tack welder including electrodes 37, 38 may be provided to tack weld the overlapping edges prior to insertion between the electrodes 18, 24. The circuit from the generator to the edges to be welded includes the resistances of the rollers, of the connectionof the rollers to their leads (the constant resiss tances R) the resistances at the contacts of the rollers with the edges, of the edges and of the interface between the edges (the varying resistances RV) and includes the inherent self inductance of the circuit and the inductance or capacitance of an inductor or capacitor included in the circuit. In Fig. 5, the ohmic resistance of the circuit is presented by Rt=Rv+R and the ohmic reactance is represented by XL. The frequency of the generator 35 supplying sinusoidal or square wave current is selected so that the ohmic reactance XL is higher than the ohmic resistance Rv so that the varying resistance Rv has little effect on the current passing between the electrodes being determined by the impedance Z=#Rt 2 +XL 2 . It is stated that the edges may be butted instead of lapped and may be of separate sheets, also that the welding may be spot or butt welding.

Improvements relating to electrical control devices for electrically driven vehicles

Abstract: 1,097,303. Variable inductors. WESTING- HOUSE BRAKE & SIGNAL CO. Ltd. June 29, 1964 [July 8, 1963], No. 26903/63. Heading H1T. In an electrically driven vehicle carrying its own power supply source, in which the speed of a D.C. traction motor is controlled by a semiconductor rectifier circuit arrangement, the rectifier circuit arranged is controlled by an output voltage from an induction regulator, the mutual coupling between two coils of which is varied by movement of manually operable means to vary said output voltage and hence the motor speed. The coupling between a pair of coils 1, 3 (Figs. 1 and 2) is varied by moving a magnetic or electrically conductive screen 5 between them. In Fig. 2 the screen may be supplemented or replaced by movable magnetic shunts 7. Alternatively in Fig. 1, the screen 5 may be omitted, and the coupling varied by moving one coil relative to the other or by rotation of core 2 relative to core 4. Also in Fig. 2 the screen 5 may be omitted and the coil 3 moved relative to coil 1. In Fig. 3 arrangement (not shown) the centre limb of an E-shaped core may be moved through the two coils toward or away from an I-shaped core which together with the E-shaped core forms a magnetic circuit. Alternatively in Fig. 3 embodiment one coil may be fixed on the E-shaped core and the other coil and I-shaped core moved relatively thereto. In an embodiment (Fig. 4) the coils 1, 3 are connected in series to an A.C. source E and a voltage output CS is taken from coil 3. The output voltage depends upon the ratio of the impedances of the coils and the impedance of each is varied by moving a short-circuited coil or ring 55 along the core 24 and eddy currents induced in the coil or ring 55 produce a flux barrier. A further coil (not shown) may be connected in series with the coil 3 and arranged as a bucking coil to allow the output voltage CS to be reduced to zero. The bucking coil would be mounted on the core remote from the coil 3. Fig. 5 embodiment (not shown) is similar to that of Fig. 4 but the magnetic circuit is provided with an adjustable core element. In all embodiments the input voltage is applied at E (e.g. at 50 c.p.s.) and the output voltage is available as indicated at CS.

Linear active network device for transforming one class nonlinear devices into another

Abstract: A linear active two-port network element for synthesizing nonlinear network components with arbitrarily prescribed characteristics. The elements, by themselves or in combination, can be utilized for a variety of applications, and are particularly useful in integrated circuit technology. The element included herein is the Mutator. The Mutator essentially transforms, or mutates one class of nonlinear devices into another; for example, a nonlinear resistor may be changed to a nonlinear inductor, a nonlinear inductor to a nonlinear capacitor, a nonlinear capacitor to a nonlinear resistor, and so on.