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Showing papers on "Decoupling capacitor published in 1991"


Patent
12 Nov 1991
TL;DR: In this article, the authors proposed a hot plug circuit, which limits the surge current generated at the interconnection of first circuits arranged on a first card and powered by a supply device.
Abstract: A hot plug circuit insuring that the plugging of cards to a board is performed in the hot-plug mode when the cards are supplied from a common power supply located on one of the cards or on the board. This circuit (62) limits the surge current generated at the interconnection of first circuits (30) arranged on a first card (1) and powered by a supply device (2) providing a first supply voltage (ground) on a first supply line (36) and a second supply voltage (+V) on a second supply line (34), with second circuit (24) on a second card powered by the supply device (2) through a third supply line (74) and fourth supply line (76). The surge current results from the charge of a decoupling capacitor of capacitance Cd arranged on the second card between the third and fourth supply lines when the cards are interconnected through an interconnecting arrangement (14, 12, 22). The hot plug circuit comprises a controlled ramp generation device connected to the first and second supply lines and activated when the connection between the first and third supply line is completed through the connecting arrangement to start the generation on the fourth supply line of a first ramp voltage Vb derived from the voltages on the first and second supply lines, said ramp voltage having an adjustable slope a=dVb/dt, whereby the surge current i which is equal to a.Cd can be limited to a desired value by adjusting the slope value a.

123 citations


Patent
27 Aug 1991
TL;DR: In this article, a printed circuit board is disclosed which includes a high capacitance power distribution core, the manufacture of which is compatible with standard printed circuit boards assembly technology, and the resulting capacitance is typically sufficient to totally eliminate the need for decoupling capacitors on a typical printed circuit.
Abstract: A printed circuit board is disclosed which includes a high capacitance power distribution core, the manufacture of which is compatible with standard printed circuit board assembly technology. The high capacitance core consists of a ground plane and a power plane separated by a planar element having a high dielectric constant. The high dielectric constant material is typically glass fiber impregnated with a bonding material, such as epoxy resin loaded with a ferro-electric ceramic substance having a high dielectric constant. The ferro-electric ceramic substance is typically a nanopowder combined with an epoxy bonding material. The resulting capacitance of the power distribution core is typically sufficient to totally eliminate the need for decoupling capacitors on a typical printed circuit board.

110 citations


Journal ArticleDOI
28 Sep 1991
TL;DR: In this article, the possibility of using an electronic switch in parallel with the running capacitor, thereby providing the equivalent of a starting capacitor, is discussed, and a starting performance similar to that of the conventional method using two capacitors can be obtained.
Abstract: The most common practice for starting a single-phase induction machine (SPIM) is to install a starting capacitor in series with the auxiliary winding. In some applications, two capacitors are used. One is used during the starting period to help create the starting torque. The other one is used during the running condition to improve efficiency. The possibility of using an electronic switch in parallel with the running capacitor, thereby providing the equivalent of a starting capacitor, is discussed. The capacitor is shorted during each cycle to vary the effective size of the AC capacitor. By using this method, only one capacitor is used for both the starting and running condition, and a starting performance similar to that of the conventional method using two capacitors can be obtained. >

105 citations


Journal ArticleDOI
TL;DR: In this article, a voltage-dependent current injection load model is presented to determine voltage waveform characteristics and additional losses at harmonic frequencies, and the optimal capacitor sizes and locations depend heavily on the load model used at fundamental frequency and on harmonic signals, especially when limits are imposed on voltage waveforms.
Abstract: The nonlinear portion of electrical loads has increased significantly in recent years. Harmonic currents injected by these loads into the distribution system should be considered when solving the capacitor placement problem in order to assure that the optimal solution does not result in excessive harmonic distortion. A voltage-dependent current injection load model is presented to determine voltage waveform characteristics and additional losses at harmonic frequencies. Computer simulations show that the optimal capacitor sizes and locations depend heavily on the load model used at fundamental frequency and on harmonic signals, especially when limits are imposed on voltage waveforms. >

99 citations


Patent
02 Aug 1991
TL;DR: In this article, a switching element with one terminal connected to a bit line of the array was used to detect the change in polarization of the ferroelectric capacitor when a voltage is applied which is not sufficient to cause a change of state of the capacitor.
Abstract: A semiconductor memory device has a plurality of memory cells in an array, into which the memory cells data is writable, and which can subsequently be read. Each memory cell has a switching element with one terminal connected to a bit line of the array another terminal connected to at least one ferroelectric capacitor, and a control terminal connected to a word line. The cell may then be operated to detect the change in polarization of the ferroelectric capacitor when a voltage is applied which is not sufficient to cause a change of state of the ferroelectric capacitor. Alternatively, a ferroelectric capacitor and a capacitor other than a ferroelectric capacitor is connected to the switching element. In a further alternative, a plurality of ferroelectric capacitors are connected to the switching element, so that different data are writable into each.

92 citations


Patent
Mauricio A. Zavaleta1
07 Nov 1991
TL;DR: In this article, a regulated charge pump (43) includes a charge pump core (114) having a charging capacitor (80), and an output voltage on a first terminal (72) of the charging capacitor(80) is transferred to a holding capacitor (81).
Abstract: A regulated charge pump (43) includes a charge pump core (114) having a charging capacitor (80). An output voltage on a first terminal (72) of the charging capacitor (80) is transferred to a holding capacitor (81). A second terminal (73) of the charging capacitor (80) is alternatively connected to positive and negative power supply voltage terminals in response to non-overlapping clock signals. The first terminal (72) of the charging capacitor (80) is connected through first (150) and second (151) transistors to the positive power supply voltage terminal. A proportional portion (112) provides a coarse regulation by biasing the first transistor (150) proportional to a comparison between a predetermined fraction of an output voltage and a reference voltage. An integrating portion (113) provides a precise regulation by biasing the second transistor (151) proportional to an integrated difference between the output voltage and a reference voltage.

86 citations


Patent
14 May 1991
TL;DR: In this paper, the authors propose a circuit for extending the sustain time of a computer power supply in the event of interruption of commercial A.C. power, which includes a capacitor bank, an associated charge path for controllably charging the capacitor bank during stable operation of the commercial AC power source, and discharge and disconnect paths for discharging the energy stored in the capacitance bank to sustain operation of computer during interruption of the AC.
Abstract: Circuitry for extending the sustain time of a computer power supply in the event of interruption of commercial A.C. power includes a capacitor bank, an associated charge path for controllably charging the capacitor bank during stable operation of the commercial A.C. power source, and discharge and disconnect paths for discharging the energy stored in the capacitor bank to sustain operation of the computer during interruption of the commercial A.C. power source and for disconnecting the capacitor from the computer power supply when the voltage across the capacitor bank has discharged below a threshold level.

83 citations


Patent
Imai Motomasa1, Hiroshi Toyoda1, Kazuhide Abe1, Koji Yamakawa1, H. Iizuka1, Mitsuo Harata1, Koji Sakui1 
28 Mar 1991
TL;DR: In this paper, a semiconductor memory device consisting of a ferroelectric capacitor, a voltage output circuit for outputting a first voltage for reversely polarizing the Ferroelectric capacitors, and a second voltage by which the polarization of the ferroelectric capacitors is not reversed, regardless of data stored in the FUs.
Abstract: A semiconductor memory device comprises a ferroelectric capacitor, a voltage output circuit for outputting a first voltage for reversely polarizing the ferroelectric capacitor and a second voltage by which the polarization of the ferroelectric capacitor is not reversed, regardless of data stored in the ferroelectric capacitor, a first reference capacitor having a such a capacitance as to accumulate less charge than charge which the ferroelectric capacitor accumulates, when the second voltage is applied to the ferroelectric capacitor, a second reference capacitor having such a capacitance that as to accumulate greater charge than the charge which the ferroelectric capacitor accumulates while the ferroelectric capacitor is forwardly polarized, when the first voltage is applied to the ferroelectric capacitor, thus reversely polarizing the ferroelectric capacitor, a sense amplifier connected to the ferroelectric capacitor and the first or second reference capacitor, a reference-capacitor selecting circuit for connecting the first reference capacitor to the sense amplifier when the voltage output circuit outputs the second voltage, and connecting the second reference capacitor to the sense amplifier while the voltage output circuit outputs the first voltage, and a circuit for determining data from the presence or absence of an electric charge in the ferroelectric capacitors while the memory is set in volatile mode, and for determining data from the direction in which the ferroelectric capacitor is polarized, while the memory is set in nonvolatile mode.

69 citations


Patent
19 Nov 1991
TL;DR: In this paper, an LCDI-type ignition apparatus for an internal combustion engine includes first and second capacitors connected to an ignition coil and a voltage source for generating a charging voltage for the capacitors.
Abstract: An LCDI-type ignition apparatus for an internal combustion engine includes first and second capacitors connected to an ignition coil and a voltage source for generating a charging voltage for the capacitors. The first capacitor is for producing an initial discharge of a spark plug, and the second capacitor is for lengthening the discharge of the spark plug after discharge has been initiated by the first capacitor. In one form of the invention, the second capacitor is charged only after the first capacitor has been charged by the voltage source to a prescribed voltage sufficient to produce a suitable discharge of the spark plug. As a result, even when the engine is operating at a high rotational speed and the time between consecutive firings of the engine is small, an adequate ignition voltage can be obtained. In another form of the invention, the charging voltage(s) of one or both of the capacitors is or are varied in accordance with the one or more engine operating conditions. Each charging voltage can be controlled to the minimum necessary value based on the present engine operating conditions.

57 citations


Patent
Colin Huggett1, Leon D. Lewis1, Robert Rudich1, John L. Scharf1, Daniel C. Blazej1 
28 Aug 1991
TL;DR: In this paper, the bus bars of the voltage convertor were integrated with a high-voltage, low-volume capacitor module to reduce the amount of stray inductance introduced by interconnection wiring.
Abstract: A high-voltage, low-volume capacitor module, having a minimal amount of inherent stray inductance, and being configured so as to allow its integration into an electrical system in a manner which minimizes any stray inductance introduced by interconnection wiring This is accomplished by integrating the capacitor into the bus bars of the voltage convertor, thereby eliminating the need for separate interconnecting wiring and reducing the overall amount of stray inductance evident within the system in which the capacitor is employed

54 citations


Journal ArticleDOI
11 May 1991
TL;DR: In this article, the authors describe the development of an electric double-layer capacitor with ultra-high capacitance and extremely low DC resistance, which consists of an activated carbon layer newly developed on aluminum foil collector electrodes, a separator and an organic electrolyte.
Abstract: The authors describe the development of an electric double-layer capacitor with ultra-high capacitance and extremely low DC resistance. The capacitance ranges from 1 F to 500 F and the DC resistance is less than one-fifth of that of the conventional capacitor with organic electrolytes. The capacitor consists of an activated carbon layer newly developed on aluminum foil collector electrodes, a separator, and an organic electrolyte. Details of the electrical characteristics and the reliability of the capacitors are presented. Several features of activated carbon electrodes and the mechanism for the improvement of the DC resistance are discussed. Some examples of the potential application of the capacitor for high-current-load uses are discussed. >

Patent
Raymond J. Kulka1
22 Nov 1991
TL;DR: In this article, a lamp is coupled to the capacitors of the voltage doubler circuit via coupling capacitor and the LC circuit to maintain the capacitor voltage above the peak of the AC supply voltage and thereby provide a circuit with a high power factor and low harmonic line current.
Abstract: A high frequency electronic ballast for a lamp (20) includes an LC filter (5) and a voltage doubler circuit (8) coupling AC input terminals (1, 2) to DC input terminals (13, 14) of a half bridge DC/AC converter circuit (15). One end of the lamp is coupled to the capacitors (16, 17) of the voltage doubler circuit via a coupling capacitor (21) and the voltage doubler diodes (11, 12) and the other end of the lamp is coupled via an LC circuit (24, 25 and 26) to a junction point (22) between first and second switching transistors (18, 19) of the half bridge circuit. A capacitor including the lamp and the LC circuit so that the half bridge circuit will oscillate at a high frequency. Energy is fed back to the voltage doubler capacitors via the coupling capacitor and the LC circuit to maintain the capacitor voltage above the peak of the AC supply voltage and thereby provide a circuit with a high power factor and low harmonic line current.

Patent
17 May 1991
TL;DR: In this article, a stacked capacitor cell structure of a semiconductor memory device was proposed to enlarge the surface area of the lower capacitor electrode without increasing the plane area exclusively occupied by memory cells.
Abstract: In a stacked capacitor cell structure of a semiconductor memory device, the MIM (metal-insulator-metal) capacitor to be used as a transfer gate comprises at least a unit stack of a first insulation film, a lower capacitor electrode, a capacitor gate insulation film, an upper capacitor electrode, another capacitor gate insulation film and an extension of the lower capacitor electrode. Thus, the surface area of the lower capacitor electrode can be enlarged without increasing the plane area exclusively occupied by memory cells. Moreover, with such a configuration, since the surface area of the lower capacitor electrode can be augmented without increasing the film thickness of the electrode, the technical difficulties that the currently known methods of manufacturing semiconductor memory devices with a stacked capacitor cell structure encounter are effectively eliminated and consequently troubles such as short-circuited lower capacitor electrodes become non-existent.

Patent
16 Apr 1991
TL;DR: In this paper, a vehicle operator protection system capable of detecting abnormalities in an auxiliary power supply in the protection system is presented, which comprises a backup capacitor which is part of a time constant circuit and is connected in parallel with an actuator for inflating an air bag.
Abstract: A vehicle operator protection system capable of detecting abnormalities in an auxiliary power supply in the protection system. The auxiliary power supply comprises a backup capacitor which is part of a time constant circuit and is connected in parallel with an actuator for inflating an air bag. While the backup capacitor is charged, the voltage differences between an onboard battery and the backup capacitor are determined for a given period, and the determined value is divided by the amount that the voltage of the backup capacitor rises in the given period. An abnormality in the capacitance of the backup capacitor is determined in accordance with the divided value, and thus the abnormality of the capacitance of the backup capacitor can be detected accurately without being influenced by variation of voltage of the onboard battery.

Patent
02 Aug 1991
TL;DR: In this paper, a VLSI device having multiple power input leads is realized by employing a sub-power plane which is physically separate from a main power distribution system on a circuit board.
Abstract: Electromagnetic filtering for a VLSI device having multiple power input leads is realized by employing a sub-power plane which is physically separate from a main power distribution system on a circuit board. The sub-power plane is placed directly under a corresponding VLSI device. Decoupling capacitors are connected to the sub-power plane and, in turn, to each of the power input leads on the VLSI device. Power is supplied from the main power distribution system to the sub-power plane via a ferrite bead type filter.

Patent
17 Sep 1991
TL;DR: In this paper, an apparatus for operating discharge lamps with a stable electric current supply and minimal dimensional area requirements is presented. But it is not shown how to operate a discharge lamp with an input power source coupled across a capacitor.
Abstract: An apparatus for operating discharge lamps with a stable electric current supply and minimal dimensional area requirements. The apparatus includes an input power source coupled across a capacitor, establishing a first loop circuit. A discharge lamp may also be connected across the capacitor, thereby forming a second loop circuit. A first switch repeatedly turns ON and OFF, making and breaking the first loop circuit at a first frequency, and thereby charges the capacitor. A second switch repeatedly turns ON and OFF, making and breaking the second loop circuit at a second frequency, and thereby discharges the capacitor through the discharge lamp. A control mechanism controls the first and second switches for supplying a predetermined current to the discharge lamp for flickerless operation.

Patent
Jang-Kyu Lee1, Seong-Wook Jeong1
22 Jan 1991
TL;DR: In this article, a pull-up/pull-down NMOS transistor pair is connected in series between a first supply voltage and a ground voltage, and a bootstrap circuit is precharged by the second supply voltage for driving the pullup transistor with a boosted voltage level when the noninverted data signal is a logic "high" state.
Abstract: A data output buffer circuit includes a pair of data lines respectively applied with a noninverted data signal and an inverted data signal and an output gate circuit for gating the noninverted and inverted data signals in response to an output enable signal. A pull-up/pull-down NMOS transistor pair is connected in series between a first supply voltage and a ground voltage. A supply voltage converter circuit generates a constant second supply voltage so long as said first supply voltage is above a predetermined minimum level. A bootstrap circuit is precharged by the second supply voltage for driving the pull-up NMOS transistor with a boosted voltage level when the non-inverted data signal is a logic "HIGH" state. The bootstrap circuit includes a first NMOS transistor, a main capacitor, a secondary capacitor, second and third NMOS transistors to precharge the secondary capacitor, an overcurrent limit circuit for limiting overcurrent into the secondary capacitor, a first CMOS inverter for transferring the boosted voltage from the main capacitor to a gate electrode of the pull-up transistor during the logic "HIGH" state, and for transferring the ground voltage during a logic "LOW" state, and a second CMOS inverter for transferring the second supply voltage to a second terminal of the main capacitor during the logic "HIGH" state, and for transferring the ground voltage thereto during the logic "LOW" state.

Patent
13 Sep 1991
TL;DR: In this paper, a tuning circuit for tuning an integrated circuit filter, such as a continuous-time MOSFET-C filter, is disclosed, which includes a switched-capacitor network (20) having a capacitor (I) which matches the capacitor used in the filter (12) to be tuned.
Abstract: A tuning circuit (18) for tuning an integrated circuit filter, such as a continuous-time MOSFET-C filter (12), is disclosed. The tuning circuit includes a switched-capacitor network (20) having a capacitor (I) which matches the capacitor used in the filter (12) to be tuned. Also included is a transistor (M) which matches the transistor used in the filter. The switched-capacitor network has a effective resistance which is a function of the switching rate of the network. Feedback circuitry is included which produces a control signal used to vary the small signal resistance of the transistor to match the effective resistance of the switched-capacitor network. The filter is tuned by varying the rate of which the switched capacitor network is clocked thereby changing to effective network resistance. The control voltage (Vc) responds by forcing the transistor resistance to match the new effective resistance of the switched-capacitor network. The control voltage is used to tune the filter and changes to compensate for variations in the filter capacitor and transistor, which track variations in the filter transistor and capacitor.

Patent
Felix K. Chen1
14 Oct 1991
TL;DR: In this article, a modulator circuit for a betatron includes an independent low voltage D.C. powder supply, an intermediate low voltage capacitor connected to one side of the betatron winding, and a high voltage capacitance connected to the other side.
Abstract: A modulator circuit for a betatron includes an independent low voltage D.C. powder supply, an intermediate low voltage capacitor connected to one side of the betatron winding, and a high voltage capacitor connected to the other side of the betatron winding. Unidirectional current devices normally permit current flow from the voltage capacitor, through the betatron winding to the high voltage capacitor. Energy is thereby transferred from the power supply and low voltage capacitor through the betatron winding to the high voltage capacitor. Switches are provided selectively to reverse the direction of current flow and thereby discharge the energy stored in both capacitors into the betatron winding to excit the betatron magentic circuit. Upon discharge of the high voltage capacitor, the unidirectional current devices once again restore normal current flow, so that the energy stored in the betatron electromagnet is returned to the high voltage capacitor. Repetition of this charging/discharging/recovery cycle pumps up the charge on the high voltage capacitor and multiplies the voltage.

Patent
27 Nov 1991
TL;DR: In a variable frequency power source unit, a series circuit of a contactless semiconductor switching element and a resistor is provided in parallel to a d.c. smoothing capacitor, and a control circuit is provided for receiving a signal for turning on the switching element selectively at any time after the power source is interrupted.
Abstract: In a variable frequency power source unit, a series circuit of a contactless semiconductor switching element and a resistor is provided in parallel to a d.c. smoothing capacitor, and a control circuit is provided for receiving a signal for turning on the switching element selectively at any time after the power source is interrupted, thereby discharging the electric charge on the d.c. smoothing capacitor.

Patent
Bang-Wan Lee1, Yl-Sung Bae1
30 May 1991
TL;DR: In this article, an improved voltage reference circuit is proposed for analog integrated circuits including A/D and D/A converters, which includes a floating gate, an isolating layer, and a controlling gate which is used to charge the capacitor to a fixed voltage.
Abstract: An improved voltage reference circuit is shown for use in analog integrated circuits including A/D and D/A converters. The voltage reference circuit comprises an operational amplifier having an non-inverting terminal connected to a capacitor. The inverting terminal of the op amp is connected to the op amp output terminal. The output terminal provides a constant reference voltage which is a function of the voltage charged in the capacitor. The capacitor includes a floating gate, an isolating layer, and a controlling gate which is used to charge (program) the capacitor to a fixed voltage. The capacitor structure is such that its charge is maintained constant over time independent of any temperature change. As a result, the voltage reference circuit prevents fluctuations in the output reference voltage throughout its operating period.

Patent
21 Oct 1991
TL;DR: In this article, a constant current source whose magnitude is proportional to capacitor values, reference voltage and input frequency is proposed, which can be used in conjunction with process invariant circuits in a variety of semiconductor technologies: CMOS, Bipolar, BiCMOS and GAS.
Abstract: The present invention is a constant current source whose magnitude is proportional to capacitor values, reference voltage and input frequency. A frequency divider provides a plurality of signals to one of a plurality of capacitor switches located within a charge generator. The outputs of the capacitor switches are combined to provide a known charge Q i to an output generator at regular intervals, t 0 =1/F in . The output generator produces an output current I out =Q i /t 0 =C i *V bg *F in , where C i is a capacitor value, V bg is a reference voltage, and F in is the input frequency. A controller provides a control signal to the output generator to limit variations in the output current I out . The preferred embodiment may be used in conjunction with process invariant circuits in a variety of semiconductor technologies: CMOS, Bipolar, BiCMOS and GAS. In one embodiment, the present invention is used in conjuction with a timer/delay circuit. In another embodiment, the present invention is used in conjunction with a calibration circuit to compensate for various inaccuracies in component performance.

Patent
16 Aug 1991
TL;DR: In this paper, a circuit for correcting power factor and for reducing ac line current harmonic components in conjunction with bridge-connected capacitive-filtered loads and for providing a source of ac startup current for associated circuitry, for example a switch mode power supply which may form part of the load.
Abstract: A circuit for correcting power factor and for reducing ac line current harmonic components in conjunction with bridge-connected capacitive-filtered loads and for providing a source of ac startup current for associated circuitry, for example a switch mode power supply which may form part of the load. The circuit comprises a rectifier bridge, a dual-tuned circuit having a tuned filter in series between an ac line input and the bridge, and a shunt capacitor across the input to the bridge. The tuned filter comprises a parallel connected inductor and capacitor, the shunt capacitor being tuned with the inductor to form a trap filter to reduce third-order and higher harmonic components in the ac line current. The circuit also includes a current source operatively connected to the shunt capacitor for providing a source of ac current immediately upon application of ac power to the ac line input.

Journal ArticleDOI
John U. Knickerbocker1, G. B. Leung1, W. R. Miller1, S. P. Young1, S. A. Sands1, R. F. Indyk1 
TL;DR: The S/390 alumina TCM fabrication processes are described and the advances they represent in processing technology, packaging density, and performance are discussed.
Abstract: Advances in multilayer ceramic (MLC) processing, the use of thin-film metallurgy wiring, and enhancements in thermal dissipation, all described in this paper, represent significant milestones in the evolution of microelectronic packaging technology. The IBM System/390™ air-cooled alumina thermal conduction module (S/390™ alumina TCM) utilizes a 127.5 × 127.5-mm MLC substrate to interconnect as many as 121 VLSI devices and 144 substrate-mounted decoupling capacitors. The substrate provides an array of 648 pads for solder connections to each device, an array of 16 pads for solder connections to each capacitor, and an array of 2772 pins for interconnection with the next package level, and contains approximately 400 m of wiring. The reduced thermal resistance design permits up to 600 W of air-cooling capacity. This paper describes the S/390 alumina TCM fabrication processes and discusses the advances they represent in processing technology, packaging density, and performance. Comparisons to prior technology are made.

Patent
Shinichi Nakagawa1, Hidenobu Ito1
30 Oct 1991
TL;DR: In this paper, a DC-DC converter includes first and second capacitors coupled in parallel, a switching part for controlling the output voltage and a discharge path breaking unit to break the discharge path.
Abstract: A DC-DC converter includes first and second capacitors coupled in parallel, a switching part for controlling the first and second capacitors so that the first capacitor is charged by an input voltage and the second capacitor is charged by a discharging of the first capacitor, an output voltage being obtained at one end of the second capacitor, and the switching part including a discharge path through which the second capacitor is discharged. An output voltage detection units detects the output voltage and determines whether or not the output voltage satisfies a predetermined condition. A discharge path breaking units breakes the discharge path when the output voltage detection unit determines that the output voltage satisfies the predetermined condition, so that the first capacitor is prevented from being discharged through discharge path.

Patent
Bertil Klerfors1
13 Feb 1991
TL;DR: A series capacitor equipment for connection into an electric power line (A) has a capacitor bank (C) and a controllable inductor connection (L, T1, T2) connected in parallel therewith and comprising a series connection of an inductor and a controlled semiconductor connection (T 1, T 2).
Abstract: A series capacitor equipment for connection into an electric power line (A) has a capacitor bank (C) and a controllable inductor connection (L, T1, T2) connected in parallel therewith and comprising a series connection of an inductor (L) and a controllable semiconductor connection (T1, T2). Further, the equipment comprises control members (CU) adapted, on the occurrence of a subsynchronous resonance oscillation, to control the semiconductor connection with separate control angle values during positive and negative half-cycles of the capacitor voltage for generation of a subharmonic voltage over the capacitor which counteracts the resonance oscillation.

Patent
04 Feb 1991
TL;DR: In this article, a capacitor-charging series resonant mode, high voltage power supply (SRMPS), is described. And the switching action causes sine wave quantums of current of alternating phase to flow through the primary winding.
Abstract: A capacitor-charging series resonant mode, high voltage power supply (SRMPS) (10) includes a switching network (30) that alternately applies a positive and negative voltage to a series resonant circuit, comprising a resonant capacitor and inductor. The inductor may include the primary winding (14) of a power transformer (12). The switching action occurs at a fixed frequency above the audible range. This frequency is approximately the resonant frequency of the series resonant circuit. The switching action causes sine wave quantums of current of alternating phase to flow through the primary winding. Secondary windings (16) of the transformer are coupled through a suitable rectifying network (18) to charge a load capacitor CL to a high voltage. During a first mode of operation the load capacitor is charged at a maximum rate. During a second mode, the load capacitor is charged only as needed to maintain a desired charge thereon. Switching between the two modes occurs automatically depending upon the capacitive load requirements. The first mode operates with a control loop open, and is used when initially charging the load capacitor. The second mode operates with the control loop closed, at a low duty cycle, and allows only a small sliver of the front end of the sine wave current quantum to flow through the primary winding.

Patent
30 May 1991
TL;DR: In this paper, a ground-free device for removing static charges from semi-conductive or conductive bodies was proposed. But it is not suitable for the removal of static charge from cars and aircraft.
Abstract: A ground-free device for removing static charges from semi-conductive or conductive bodies. The device includes a storage capacitor, a conductive contact connected to the storage capacitor, and an air capacitor connected to the storage capacitor, in which a voltage below the breakdown voltage of the air is imposed on the air capacitor, e.g., by an RC-controlled transistor oscillator circuit. The device provides high efficiency removal of static charge, e.g., from the metallic bodies of cars and aircraft.

Patent
14 May 1991
TL;DR: Sigma-delta analog to digital converters based upon switched capacitor delay and switched capacitor differentiator circuits are described in this paper, which have the advantages that they are less sensitive to clock feed-through noise, dc offset voltage and power supply voltage, etc.
Abstract: Sigma-delta analog to digital converters based upon switched capacitor delay and switched capacitor differentiator circuits are described. These switched capacitor circuits have the advantages that they are less sensitive to clock feed-through noise, dc offset voltage and power supply voltage, etc. Design examples of one-bit second-order sigma-delta analog digital converter are given to substantiate both design methodology, circuit features and the utility of these new circuit structures.

Patent
Cox Percy Terrell1
23 Dec 1991
TL;DR: In this article, a water cut meter includes a test cell through which a petroleum stream will flow, which includes an outer shell, a sensor probe which cooperates with the outer shell to form a sensor capacitor with the flow of the petroleum stream as the dielectric and a reference probe surrounded with pure oil as the deadlectric.
Abstract: A water cut meter includes a test cell through which a petroleum stream will flow. The test cell includes an outer shell, a sensor probe which cooperates with the outer shell to form a sensor capacitor with the flow of the petroleum stream as the dielectric and a reference probe surrounded with pure oil as the dielectric to form a reference capacitor. Processing apparatus includes a comparator network electrically connected to the sensor capacitor and to reference capacitor which compares the capacitance of the sensor capacitor with the capacitance of the reference capacitor. The comparator network provides a signal corresponding to the capacitance difference between the sensor and reference capacitors. An output circuit connected to the comparator network provides an output corresponding to the water cut of the petroleum stream in accordance with the signal from the comparator network.