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Showing papers on "RLC circuit published in 1985"


Journal ArticleDOI
TL;DR: In this paper, a planar, thin-film DC SQUID was coupled to a spiral input coil to form a resonant circuit, where the capacitive feedback between the output of the SQUID and the input circuit was dominated by capacitance.
Abstract: The impedance of a circuit coupled magnetically via a mutual inductanceM i to a dc SQUID of geometric inductanceL is modified by the dynamic input impedance of the SQUID, which can be characterized by the flux-to-current transfer functionJ Ф≡∂J/∂Ф;J is the current circulating in the SQUID loop and Ф is the flux applied to the loop. At the same time, the SQUID is modified by the presence of the input circuit: in the lumped circuit approximation, one expects its inductance to be reduced toL r=(1−α 2 )L, where α e is an effective coupling coefficient. Calculations of JФ using an analog simulator are described and presented in the form of a dynamic inductance ℒ and a dynamic resistance ℛ versus bias currentI and Ф. Experimental measurements of ℒ and ℛ were made on a planar, thin-film SQUID tightly coupled to a spiral input coil that was connected in series with a capacitorC i to form a resonant circuit. Thus,J Ф was determined from the change in the resonant freqency and quality factor of this circuit as a function ofI and Ф. At low bias currents (low Josephson frequencies) the measured values of ℒ were in reasonable agreement with values simulated for the reduced SQUID, while at higher bias currents (higher Josephson frequencies) the measured values were in better agreement with values simulated for the unscreened SQUID. Similar conclusions were reached in the comparison of the experimental and simulated values of the flux-to-voltage transfer functionV Ф. The reduction in the screening at the higher Josephson frequencies is believed to result from the parasitic capacitanceC p between the SQUID and the input coil. In contrast to the behavior of the input inductance, the change in the input resistance ΔR i could not be explained in terms of the dynamic impedance of the SQUID reflected into the input circuit. Instead, ΔR i was dominated by capacitive feedback between the output of the SQUID and the input circuit viaC p . The experimental values of ΔR i were satisfactorily explained by a simplified model that predicts ΔR i ⋍−M iV Ф r (C p /C i ).

83 citations


Journal ArticleDOI
TL;DR: In this paper, an analysis of a resonant converter which contains a capacitive-input output filter, rather than the more conventional inductor-input input filter, is presented along with design curves along with experimental data.
Abstract: Resonant dc-dc converters offer several advantages over the more conventional PWM converters. Some of these advantages include: 1) low switching losses and low transistor stresses; 2) medium speed diodes are sufficient (transistor parasitic, inverse-parallel diodes can be used, even for frequencies in the hundreds of kilohertz); and 3) ability to step the input voltage up or down. This paper presents an analysis of a resonant converter which contains a capacitive-input output filter, rather than the more conventional inductor-input output filter. The switching waveforms are derived and design curves presented along with experimental data. The results are compared to the inductor-input filter case obtained from an earlier paper.

76 citations


Patent
17 May 1985
TL;DR: In this paper, a separable high frequency transformer with a primary permanently mounted to the power supply apparatus and a secondary mounted about the power consuming apparatus is used for transferring electrical power between a power supplying apparatus and power consuming devices.
Abstract: Apparatus for transferring electrical power between a power supplying apparatus and power consuming apparatus and having a separable high frequency transformer with a primary permanently mounted to the power supply apparatus and a secondary mounted about the power consuming apparatus A charging control circuit mounted on the consuming apparatus, eg a mobile vehicle includes means for detecting current and voltage delivered through the transformer, and also for monitoring storage batteries within the vehicle The power supply apparatus includes a power supply circuit comprising a ferrite core transformer and capacitor forming a parallel resonant circuit The primaries of the transformer are alternately driven by a driver about opposing polarities The drivers are controlled by a voltage-controlled pulse-width modulator which provides a square wave input to the drivers to cause them to alternatively energize the ferrite core transformer Power is transferred across the inductor to the resonant circuit as portions of a sine wave The power supply circuit also includes an internal current sensing circuit to shut current build-up down when current in the resonant circuit becomes too high, and an external control loop which senses power demands of the charging control circuit delivered via an optical communications link within the separable transformer

71 citations


Journal ArticleDOI
TL;DR: In this article, the concept of a new HVDC circuit breaker for 500 kV and its operating principle are explained, and the interruption of the direct current is based on a "passive" commutation circuit.
Abstract: The concept of a new HVDC circuit- breaker for 500 kV and its operating principle are explained. The interruption of the direct current is based on a "passive" commutation circuit.

68 citations


Patent
23 Dec 1985
TL;DR: In this paper, a multicoin tester has a coin inlet path 1 along which coins under test run edgewise past coils 2, 3 on opposite sides of the path, and through the windings of a coil 4.
Abstract: A multicoin tester has a coin inlet path 1 along which coins under test run edgewise past coils 2, 3 on opposite sides of the path, and through the windings of a coil 4. Electronic circuitry responsive to the inductive coupling of the coin with the coils operates a gate 5 to either reject the coin onto path 1b or to accept the coin into path 1a. As shown in FIG. 2 each of the coils 2, 3 and 4 is arranged in a parallel L-C resonant circuit 10, 11, 12 connected in the feedback path of an amplifier A1, the resonant circuit being energised sequentially by multiplexer M1. Each of the circuits 10, 11 and 12 has its own natural resonant frequency. The resonant circuits 10, 11, 12 are driven by a voltage controlled oscillator VCO. A phase locked loop including a phase comparator PS1 drives the oscillator VCO at a frequency corresponding to the natural resonant frequency of whichever of the circuits 10, 11 and 12 is connected thereto. As a coin passes say the coil 2, the resonant frequency of circuit 10 is modified by the coin and the phase locked loop changes the frequency of the VCO to maintain resonance. The resulting output at 15 varies both in amplitude and frequency. The amplitude deviation is digitized by an analogue to digital coverter ADC and compared by a microprocessor MPU with stored values in an EEPROM to determine coin acceptability and denomination; so as to operate gate 5 and provide other optional outputs.

53 citations


Patent
Soo C. Seo1
22 Aug 1985
TL;DR: In this article, two metal sensing apparatuses are used in an operable toy to cause the toy to follow a track of metallic or magnetic material, and the power to the motor is reversed when the metal or magnetic object is sensed.
Abstract: An operable toy utilizes a metal sensing apparatus which includes a tuned circuit which includes a pick-up coil. The resonance frequency of the resonance circuit shifts when the pick-up coil senses a metal or magnetic object. A motor is normally driven in the absence of the sensing of a metal or magnetic object. When the metal or magnetic object is sensed, the frequency shift of the tuned circuit including the pick-up coil attenuates the frequency produced by an oscillator and as the voltage of the signal produced by the oscillator is attenuated, a level detection circuit produces a low output to thereby disconnect the power from the motor. Alternatively, the power to the motor may be reversed. Two metal sensing apparatuses may be utilized in an operable toy to cause the toy to follow a track of metallic or magnetic material.

49 citations


Patent
15 Aug 1985
TL;DR: In this article, a tunable notch filter for the front end of an RF receiver includes magnetically coupled input and output tunable stages each responsive to a tuning voltage provided by the receiver.
Abstract: A tunable notch filter for the front end of an RF receiver includes magnetically coupled input and output tunable stages each responsive to a tuning voltage provided thereto. Each of the input and output stages includes a respective series and parallel resonant circuit wherein the parallel resonant circuits are tuned to a selected RF frequency and the series resonant circuits are tuned to a frequency approximately equal to that of a local oscillator. By using the series resonant circuits to create a notch at a frequency approximating that of the local oscillator, conducted local oscillator leakage from the receiver's antenna is substantially reduced and local oscillator image frequency rejection is substantially improved.

39 citations


Patent
06 Feb 1985
TL;DR: In this paper, a power supply for supplying regulated power to an output from an unregulated DC voltage source is provided, which includes low and high power series resonant converters, each including a pair of power switches which are alternately turned on and off for completing a series resonance circuit with the source and with a primary winding of a transformer coupled to the output.
Abstract: A power supply is provided for supplying regulated power to an output from an unregulated DC voltage source. The supply includes low and high power series resonant converters, each including a pair of power switches which are alternately turned on and off for completing a series resonant circuit with the source and with a primary winding of a transformer coupled to the output. A switch control responds to loading of the output and drives the switches on and off at an operating frequency that varies with the loading. A converter control monitors the operating frequency and controls operation of the converters such that one or both converters operate in dependence upon loading to avoid operation within a particular frequency range.

39 citations


Proceedings ArticleDOI
29 May 1985

29 citations


Patent
Robert T. Flegal1
31 Jul 1985
TL;DR: In this paper, a series resonant drive circuit for producing pulses of a predetermined frequency, a transformer for coupling the drive circuit to a TFEL panel, and symmetrically driven push-pull row drivers, a plurality of which may be implemented on a single integrated circuit chip.
Abstract: A drive network for a TFEL panel includes a series resonant drive circuit for producing pulses of a predetermined frequency, a transformer for coupling the drive circuit to a TFEL panel, and symmetrically driven push-pull row drivers, a plurality of which may be implemented on a single integrated circuit chip. The transformer includes switching means for alternately providing positive and negative high-voltage pulses for the row drivers on alternate frames of data. The network formed by the series resonant drive circuit and the TFEL panel is a series RLC circuit which is driven at its resonant frequency.

27 citations


Patent
25 Apr 1985
TL;DR: In this article, a tuned circuit radio frequency power supply is disclosed, in which a conventional voltage doubler drives a power oscillator having a variable output frequency and variable duty cycle.
Abstract: A tuned circuit radio frequency power supply is disclosed. A conventional voltage doubler drives a power oscillator having a variable output frequency and variable duty cycle. The power oscillator output is connected to a tuned RLC circuit incorporating a load. A voltmeter coupled to the circuit measures overall phase of the RLC circuit and inputs to a phase comparator within the oscillator. Tuning of the RLC circuit is done by frequency comparison with circuit lead requiring increased oscillator frequency and circuit lag requiring decreased oscillator frequency. An ammeter is placed in series with the neon circuit and controls the oscillator duty cycle to maintain constant current despite changes in load. Consequently, power is adjusted from the oscillator, preferably by varying trigger level on a ramp voltage generator. In the case of a neon lamp power supply, there results a light weight power supply having a small radio frequency inductance which strikes the neon lamp, maintains the neon lamp at minimum energy levels, adjusts the lamp to various changes in operating parameters and lessens fire danger and minimizes radio frequency interference. In the case of conventional power supplies there is a power supply which does not require choking, has low switching losses and utilizes a small and compact step-down transformer as illustrated.

Patent
07 Nov 1985
TL;DR: In this paper, a drift tube is used to amplify high-frequency multikilowatt, amplitude-modulated signals using a linear beam of electrons which is density modulated by a permeable control grid 24 spaced close to a thermionic cathode.
Abstract: A tube for amplifying high-frequency multikilowatt, amplitude-modulated signals utilizes a linear beam of electrons which is density-modulated by a permeable control grid 24 spaced close to a thermionic cathode 22. The beam is focused through a drift tube 17 having two axially spaced gaps 18, 35, each coupled to a resonant circuit 84,26 such as a hollow cavity. The first circuit 84 is tuned to a resonant frequency higher than the signal frequency to produce velocity-modulation bunching of the beam electrons in phase with the density-modulation from the grid. The second circuit 26 is tuned to the signal frequency and its energy is coupled out to an external load. The grid modulation is Class B or Class C so there is no current between the electron bunches. The floating bunching circuit 84 can thus, by velocity modulation, produce very dense bunches to excite the output circuit 26, providing very high conversion efficiency. The tube is particularly adapted to amplitude-modulated signals such as television, for which a conventional klystron yields very low average efficiency.

Journal ArticleDOI
TL;DR: In this article, three multigigahertz-bandwidth lumped-element optical-guided-wave Mach-Zehnder interferometric modulators have been designed, fabricated in LiNbO 3, tested, and analyzed.
Abstract: Multigigahertz-bandwidth lumped-element optical-guided-wave Mach-Zehnder interferometric modulators have been designed, fabricated in LiNbO 3 , tested, and analyzed. Three modulators were built having 3 dB bandwidths of 2.75, 4.4, and 7.3 GHz with V π 's of 7, 14, and 28 V, respectively. A simple RLC equivalent circuit model adequately predicts the packaged modulator performance. Coupled with previously reported work, this demonstrates the ability to reliably design and fabricate lumped-element modulators which operate from dc through 7.3 GHz.

Patent
26 Aug 1985
TL;DR: In this paper, a line deflection coil forms part of a resonant circuit whose tuning frequency is substantially equal to half the line frequency, as a result of which the power dissipation is kept low.
Abstract: A picture pick-up or display device, respectively for recording a scene or displaying a scene image, respectively with the aid of a line raster formed by a plurality of horizontal lines which are consecutively scanned in opposite directions. The device comprises a line deflection circuit in which the line deflection coil forms part of a resonant circuit whose tuning frequency is substantially equal to half the line frequency, as a result of which the power dissipation is kept low. By means of a control circuit it is ensured that corresponding points of scanned lines are accurately in line in the vertical direction, the control circuit being arranged for causing a zero-crossing of the line deflection current and a signal which is characteristic of half the video information of a line substantially to coincide. The control circuit comprises an analogue delay element for setting the time position of this signal.

Journal ArticleDOI
TL;DR: In this paper, the equilibrium and transient behavior of a class of nonlinear RLC circuits driven externally by deterministic inputs and internally by thermal noise from linear resistors is studied.
Abstract: This paper addresses the equilibrium and transient behavior of a class of nonlinear RLC circuits driven externally by deterministic inputs and internally by thermal noise from linear resistors. Resistor noise is described by the standard Nyquist-Johnson model [1], [2]. Physical principles from thermodynamics are formulated as theorems concerning the stochastic differential equation and the associated forward Kolmogorov equation describing the network and are proved on a rigorous basis. The forward Kolgomorov equation governing the evolution of the probability density for certain capacitor charges and inductor fluxes is shown to be an infinite dimensional dissipative dynamical system in the sense of Willems [3]. By this route we demonstrate that essentially all the principles of thermodynamics for this class of systems can be derived as mathematical consequences of the Nyquist-Johnson model for thermal noise in linear resistors. A significant clarification of thermodynamic theory results from this formulation, since the mathematical framework and a number of specific conclusions are valid for transient as well as equilibrium behavior.

Patent
13 Sep 1985
TL;DR: In this paper, a batteryless, portable, frequency divider, consisting of a single resonant circuit including a nonlinear inductor having a core made of amorphous magnetic material; and a capacitance connected in series with the inductor to define a circuit that detects electromagnetic radiation at a first predetermined frequency and responds to said detection by transmitting electromagnetic radiation on a second frequency that is a subharmonic of the first frequency.
Abstract: A batteryless, portable, frequency divider, consisting of a single resonant circuit including a nonlinear inductor having a core made of amorphous magnetic material; and a capacitance connected in series with the inductor to define a resonant circuit that detects electromagnetic radiation at a first predetermined frequency and responds to said detection by transmitting electromagnetic radiation at a second frequency that is a subharmonic of the first frequency. The resonant circuit may further include a second inductor connected in series with the nonlinear inductor and the capacitance to define the resonant circuit. The core of the nonlinear inductor includes an elongated thin flat ribbon of low coercivity amorphous magnetic material. It has been observed that the resonant circuit exhibits a bifurcated frequency-division characteristic in relation to the amplitude of the detected electromagnetic radiation at the first predetermined frequency, whereby additional frequency divisions occur as the amplitude is increased. This bifurcation characteristic is utilized in a presence detection system that uses a tag containing the frequency divider. The system transmits electromagnetic radiation at the first frequency into a surveillance zone and detects multiple subharmonic frequencies to detect the presence of the tag in the surveillance zone.

Patent
14 Mar 1985
TL;DR: In this paper, a device for transmitting binary data between a mobile data carrier (10) and a stationary station (11) is provided with a first resonance circuit (13) in the stationary station, whereby a switchable field effect transistor (25) is parallel switched to its condenser (17) by means of a switching pulse sequence.
Abstract: A device for transmitting of binary data between a mobile data carrier (10) and a stationary station (11) is provided with a first resonance circuit (13) in the stationary station (11), whereby a switchable field effect transistor (25) is parallel switched to its condenser (17) by means of a switching pulse sequence, a second resonance circuit (12) in the data carrier (10) which is at least conductively coupled for a short time with the first resonance circuit (13). For the purpose of enlarging the inductively to be bridged distances between the resonance circuits (12,13) of data carrier (10) and stationary station (11) without impairing the operating safety during the data transmission the resonance circuit (13) in the stationary station (11) is designed in such a manner that its resonance frequency is about equal to the switching pulse sequence. The data transmission from the data carrier (10) to the stationary station (11) is performed by amplitude demodulation in the data carrier (10) and by amplitude demodulation in the stationary station (11). The data transmission from the stationary station (11) to the data carrier (10) is performed by frequency demodulation, whereby the frequency ratio is adjusted to 2:1.

Patent
Hettiger James1
28 Feb 1985
TL;DR: In this paper, the circuit impedance is selected to cause cancellation in the inductive branch between image frequency component coupled by the first coupling and image frequency components coupled by a second coupling, without substantially affecting the desired signals.
Abstract: In a superheterodyne receiver, such as a typical television receiver, a radio frequency coupling arrangement includes a first resonant circuit coupled to receive the input signal and further coupled to a second resonant circuit by a first coupling. Both resonant circuits are tuned to the desired signal frequency. The capacitive branch of the first resonant circuit includes a circuit impedance for providing a neutralizing voltage, at least a portion of which is coupled by a second coupling to the inductive branch of the second resonant circuit. The circuit impedance is selected to cause cancellation in the inductive branch between image frequency components coupled by the first coupling and image frequency components coupled by the second coupling, without substantially affecting the desired signals.

Patent
30 Jul 1985
TL;DR: In this paper, a trace switch is coupled to a line deflection winding and a trace capacitance for applying a trace voltage to the deflection wound to generate line scanning current in the retrace winding.
Abstract: A trace switch, operated at a line rate, is coupled to a line deflection winding and a trace capacitance for applying a trace voltage to the deflection winding to generate line scanning current in the deflection winding. A deflection retrace capacitance is coupled to the deflection winding for forming a deflection retrace resonant circuit during the line retrace interval to generate a deflection retrace pulse voltage. A modulator inductance is coupled to the trace switch and to the line deflection winding. A modulator switch applies a line rate, switched mode, modulation voltage directly to the modulator inductance to control the amplitude of the current in the modulator inductance at the end of the line trace interval. A modulator retrace capacitance is coupled by the modulator switch to the modulator inductance during the line retrace interval for forming a modulator retrace resonant circuit. The switched mode modulation voltage is varied at a field rate to provide side pincushion correction to the line scanning current.

Patent
Graham David Lill1
15 Mar 1985
TL;DR: In this article, a current supply source is provided along with control elements and switching means for changing the operating mode of the oscillator from a standby mode to an oscillatory mode, and vice versa.
Abstract: An electric oscillator comprising a resonant circuit wherein, after switching on the oscillator, it takes a short time to build up to a desired amplitude of oscillation. To reduce the oscillation build-up time of the oscillator, a current supply source is provided along with control elements and switching means for changing the operating mode of the oscillator from a standby mode to an oscillatory mode, and vice versa. During the standby mode a charging current is supplied to the coil of the resonant circuit so that when switching over into the oscillatory mode, the charging current to the coil is interrupted. As a result, the control elements are immediately supplied with oscillations of the desired oscillatory amplitude.

Patent
29 Nov 1985
TL;DR: In this article, an apparatus for generating a periodic resonant pulse voltage across an inductance includes first and second switches coupled together in a series cascode arrangement, where the cascode applies a first voltage to the inductance for storing energy therein, and a second switch is coupled to the control electrode of the first switch for supplying current to the second switch during conduction of the damper switch.
Abstract: An apparatus for generating a periodic resonant pulse voltage across an inductance includes first and second switches coupled together in a series cascode arrangement. The cascode arrangement applies a first voltage to an inductance for storing energy therein. A periodic switching signal is coupled to the second switch. Each cycle of the switching signal includes a turn-on portion and a turn-off portion. The initiation of the turn-off portion makes the second switch nonconductive to enable the inductance and a resonating capacitance to form a resonant circuit that generates a resonant pulse voltage at a terminal of the resonant circuit. A damper switch is coupled to the inductance for terminating the generation of the resonant pulse voltage at the end of the first interval, prior to the initiation of the turn-on portion of the switching signal. The voltage at the resonant circuit terminal is coupled to the control electrode of the first switch for supplying current thereto during conduction of the damper switch. This enables the first switch to conduct current from the inductance during conduction of the second switch.

Patent
13 May 1985
TL;DR: In this article, a non-bifilar wound transformer with resonant capacitors serving the dual function of suppressing diode voltage switching transients while forming the resonant circuit in conjunction with the transformer.
Abstract: A resonant converter feeds five load circuits while maintaining excellent voltage regulation. The power converter features a non-bifilar wound transformer with the resonant capacitors serving the dual function of suppressing diode voltage switching transients while forming the resonant circuit in conjunction with the transformer. Overcurrent circuit protection is also provided.

Patent
Shigeru Tanaka1, Fumio Ishiyama1
06 Sep 1985
TL;DR: In this article, a power supply circuit of voltage resonance type for supplying a high DC voltage to an X-ray tube includes a transformer, a capacitor for forming a resonance circuit in cooperation with a primary winding of the transformer, and a rectifier circuit coupled with a secondary winding of a transformer.
Abstract: A power supply circuit of voltage resonance type for supplying a high DC voltage to an X-ray tube includes a transformer, a capacitor for forming a resonance circuit in cooperation with a primary winding of the transformer, and a rectifier circuit coupled with a secondary winding of the transformer for supplying a high DC voltage to the x-ray tube. At the beginning of the operation of the power supply circuit, a great change of resonance conditions is offset to quicken the rise of the X-ray tube voltage. To this end, a power supply drive circuit to enable (turn on) the switches is arranged to prevent the switches from being enabled before one cycle of the resonance current in the resonance circuit is completed.

Patent
19 Jun 1985
TL;DR: In this article, a multiple repetitive resonant railgun power supply provides energy for repetitively propelling projectiles from a pair of parallel rails, where a plurality of serially connected paired parallel rails are powered by similar power supplies.
Abstract: A multiple repetitive resonant railgun power supply provides energy for repetitively propelling projectiles from a pair of parallel rails. A plurality of serially connected paired parallel rails are powered by similar power supplies. Each supply comprises an energy storage capacitor, a storage inductor to form a resonant circuit with the energy storage capacitor and a magnetic switch to transfer energy between the resonant circuit and the pair of parallel rails for the propelling of projectiles. The multiple serial operation permits relatively small energy components to deliver overall relatively large amounts of energy to the projectiles being propelled.

Patent
25 Nov 1985
TL;DR: In this article, a linearity correction circuit for correcting asymmetrical linearity errors of the line deflection current includes a resonant capacitor coupled to a first inductor for forming a circuit having a resonance frequency greater than or equal to the deflection retrace frequency.
Abstract: A linearity correction circuit for correcting asymmetrical linearity errors of the line deflection current includes a resonant capacitor coupled to a first inductor for forming a resonant circuit having a resonant frequency greater than or equal to the deflection retrace frequency. A controllable switch coupled to the resonant circuit and to the deflection trace capacitor becomes conductive at the beginning of retrace to generate an oscillatory current pulse in the resonant circuit that removes a predetermined amount of charge from the trace capacitor during retrace. A second, relatively large valued inductor is coupled to the line deflection winding and is responsive to the deflection retrace pulse voltage for supplying during the trace interval a linearity correction current to the trace capacitor via the resonant capacitor.

Patent
21 May 1985
TL;DR: In this paper, a picture reproducing device with a picture tube is described, in which the operating voltage (UB) is in series with an electronic switch (S) with an anti-parallel connected freewheeling diode (D) and the primary winding (4) of the transformer.
Abstract: The invention relates to a switched power supply for a picture reproducing device with a picture tube, in which the operating voltage (UB) is in series with an electronic switch (S) with an anti-parallel connected freewheeling diode (D) and the primary winding (4) of the transformer (3) The primary winding (4) is completed to form a resonant circuit by a capacitor (CA) The switch (S) is operated periodically by a control circuit (5) A high voltage (U)Hoch) and a focus voltage (UF) for the picture tube are generated by a diode- connected split winding (8) Another secondary winding (8) with tappings (a to g) is connected to half-wave rectifier circuits (Da to Dg, Ca to Cg) and supplies all the required secondary voltages for the picture reproduction device

Patent
30 Aug 1985
TL;DR: In this article, a line raster consisting of a plurality of horizontal lines which are consecutively scanned in opposite directions is used for picture pick-up or display device, respectively for recording a scene or displaying a scene image.
Abstract: A picture pick-up or display device, respectively for recording a scene or displaying a scene image, respectively with the aid of a line raster formed by a plurality of horizontal lines which are consecutively scanned in opposite directions. The device comprises a line deflection circuit (1-4) in which the line deflection coil (1) forms part of a resonant circuit whose tuning frequency is substantially equal to half the line frequency, as a result of which the power dissipation is kept low. By means of a control circuit (7-13) it is ensured that corresponding points of scanned lines are accurately in line in the vertical direction, the control circuit being arranged for causing a zero-crossing of the line deflection current and a signal which is characteristic of half the video information of a line substantially to coincide. The control circuit comprises an analogue delay element (9) for setting the time position of this signal.

Patent
08 Mar 1985
TL;DR: In this article, a low noise oscillator is described where the collector and base of a transistor are respectively biased at different voltages from a common voltage source to generate a high frequency oscillation with a resonant circuit connected to the emitter and collector.
Abstract: A low noise oscillator is disclosed wherein the collector and base of a transistor are respectively biased at different voltages from a common voltage source to be conditioned for generating a high frequency oscillation with a resonant circuit connected to the emitter and collector. The high frequency oscillation developed at the base of the transistor is coupled to ground. A capacitive circuit is coupled between the collector and base of the transistor to eliminate the effect of a voltage-dependent capacitance inherently present in the transistor between its collector and base on the frequency of the oscillation in order to reduce the level of noise introduced to sidebands.

Proceedings ArticleDOI
M. Banu1, Yannis Tsividis
01 Jan 1985
TL;DR: In this article, the authors present a complete, integrated system including a fifth-order elliptic low-pass filter and a Phase-Locked Loop (PLL) control circuit for the automatic tuning of the filter.
Abstract: A TECHNIQUE BASED ON FULLY-BALANCED topologies was recently introduced for the design of monolithic active RC filters in MOS technology’. These circuits work in continuoustime, have a wide dynamic range and are voltage tunable. The latter capability can be used to reference accurately their frequency responses to an external clock signal similar to another method2. This report will present a complete, integrated system including a fifth-order elliptic low-pass filter and a Phase-Locked Loop (PLL) control circuit for the automatic tuning of the filter. The system diagram is shown in Figure 1, and the chip microphotograph in Figure 2. The fabrication technology was a twintub CMOS with 3.5p minimum linewidths. The power supplies used were I5V. The design followed closely the classical method of active RC circuits. The filter was synthesized from a passive RLC ladder network using a ladder-simulation technique. The element values were chosen so that a standard elliptic transfer could be realized. The transistors used as voltage-controlled resistors with nonlinearity cancelation’ and the capacitors were scaled properly pair by pair to optimize the filter for dynamic range;in such balanced networks all capacitors and MOSFET resistors appear in pairs of identical elements. A 0.5dB peaking in the frequency response due to opamp finite bandwidth and transistor intrinsic distributed parasitic capacitances was eliminated at the simulation stage by slightly modifying the values of two capacitors in a pair. The channel width of the transistors was 4 p and the channel lengths were 1 6 0 ~ 200p and 400p (channel length of unit transistor was 40p; no cross-connecting was used for easy layout). The balanced operational amplifiers were implemented with pairs of regular operational amplifiers and p t u b resistors for simplicity. Their unity-gain bandwidth is 1MHz. The voltage-controlled oscillator (VCO) of the PLL was implemented with a second-order fully-balanced active RC network. Ideally, this state-variable topology realizes poles precisely on the jw axis. Since the predictable nonidealities of this circuit automatically ensures it instability, no special care had to be taken to produce oscillations. To limit the output signal level, thus preserving good spectral purity, two diodeconnected transistors were added. The transistors and capacitors of the VCO were laid out in close proximity to the respective elements of the filter as shown in Figure 2. This is important to improve the frequency characteristics matching of the master VCO with the s h e filter. Two voltage-comparators were used to guarantee that the inputs to the phase comparator are square -

Patent
01 Jun 1985
TL;DR: In this article, an exciting signal having a frequency coincident to each of inherent frequencies of a piezoelectric element which arbitrarily selects a measurement range of temperature and sending an echo signal from the resonance circuit of a sensor which is disposed adjacent to the bearing is presented.
Abstract: PURPOSE:To accurately measure temperature of a bearing by scanning an exciting signal having a frequency coincident to each of inherent frequencies of a piezoelectric element which arbitrarily selects a measurement range of temperature and sending an echo signal from the resonance circuit of a sensor which is disposed adjacent to the bearing CONSTITUTION:A sensor 15 is embedded in the bearing housing part 14 of a connecting rod 10 The terminal point of the sensor 15 is adjacent to a bearing 11 The body 17 of the sensor 15 has a piezoelectric element 18 engaged at the tip end thereof and has a receiving antenna 19 at the opposed based end thereof Both the element 18 and the antenna 19 are connected by a lead wire 20, which has a tunning element 21 on the way thereof A resonance circuit 22 is thus made up A transmitter antenna 23 is disposed along the internal face of a crankcase 13, which is connected to a transceiver 24 and a warning device 25 in order An exciting signal having a frequency corresponding to each of temperature values which are arbitrarily selected within a range of measured values is sent from the transceiver 24 to the resonance circuit 22 via the transceiver antenna 23