Showing papers on "Capacitor published in 1977"

Sampled analog filtering using switched capacitors as resistor equivalents

Abstract: The equivalence between resistor-capacitor (RC) filtering circuits and circuits containing switches and ratioed capacitors is examined. The authors have demonstrated the advantages of ratioed capacitors for integrated active filters experimentally, using a specially designed integrated MOS test chip. Polysilicon gate technology was used to fabricate the chip, with the capacitors being formed by two levels of polysilicon. For the theoretical description, and as a design aid, attention is drawn to the general equivalence between a resistor and a circuit element consisting of a capacitor and two switches. Nonideal effects, which set limits to the generality, are also discussed.

DC-to-DC switching converter

Abstract: A dc-to-dc converter having nonpulsating input and output current uses two inductances, one in series with the input source, the other in series with the output load. An electrical energy transferring device with storage, namely storage capacitance, is used with suitable switching means between the inductances to DC level conversion. For isolation between the source and load, the capacitance may be divided into two capacitors coupled by a transformer, and for reducing ripple, the inductances may be coupled. With proper design of the coupling between the inductances, the current ripple can be reduced to zero at either the input or the output, or the reduction achievable in that way may be divided between the input and output.

Field- and Time-Dependent Radiation Effects at the SiO2/Si Interface of Hardened MOS Capacitors

Abstract: The field and temperature dependence of the interface-state density as a function of time following pulsed e-beam irradiation, and the dose dependence of the interface-state density following steady state Co60 irradiation were examined in MOS capacitors with both hardened dry and wet (pyrogenic) gate oxides. From the results of the pulsed e-beam experiment, we show that in the wet oxide the electric field affects the time scale for the buildup of interface states as well as the final or saturation value of interface states at late times (~105 s), but that in the dry oxide there is no marked field dependence. For the wet oxide, we observed that temperature affects only the time scale for the buildup of interface states. From total-dose Co60 measurements, we report a power law dependence on dose, D0.65, for both wet and dry oxide capacitors. The buildup of interface states in the wet-oxide capacitors is considerably larger than in the dry.

Weighted capacitor analog/digital converting apparatus and method

Abstract: An array of binary weighed capacitors, an additional capacitor having a capacitance value equivalent to that of the least of the binary weighted capacitors, a voltage comparator, switches for interconnecting the capacitors with certain predetermined voltage levels and the comparator, and a sequencing circuit are included. One side of all of the capacitors is connected to one input terminal on the comparator and the other side has applied thereto the signal to be quantized. Switch sequencing combines divided portions of a reference voltage with the signal to be quantized for presentation to the input of the comparator which thereby provides a serial digit output connected to the sequencing circuit. In this fashion, a linear conversion between an analog and a digital signal is made by the sequencing circuit. A nonlinear converter between digital and analog signal presentation is also disclosed.

High voltage signal coupler for a distribution network power line carrier communication system

Abstract: A high voltage signal coupler couples carrier communication signals between a distribution network primary conductor and communication elements located at spaced intervals on the distribution network. A single bushing, high frequency, coupling capacitor communicates the carrier communication signals between one of the distribution network primary conductors and a conductor which is at ground or real earth potential with respect to power current frequencies. A parallel resonant circuit, formed by a tuning capacitor and a hollow core of magnetic material inductively surrounding the power frequency ground conductor, couples the carrier communication signals to the communication elements connected thereto at a predetermined frequency without interfering with the operation of the ground conductor at the frequency of the power current.

Transient voltage suppression system

Abstract: An improved transient voltage suppression system for use in an electrical power distribution system which includes at least one power line and a neutral or ground line. The system includes a suppression circuit for each power line of the power distribution system, with each suppression circuit being coupled between a corresponding power line and the neutral or ground line. Each suppression circuit includes a first and second metal oxide varistors each coupled in series with corresponding first and second switching resistors and thermally coupled thereto, and a third metal oxide varistor coupled in parallel with the series connections of the first and second metal oxide varistors and the first and second switching resistors. A capacitor is coupled in parallel with the third metal oxide varistor. Coupled between each suppression circuit and a corresponding power line is a fuse for protecting the components of the circuits from current surges. A light-emitting diode is coupled in parallel with each fuse to emit light when the corresponding fuse is blown. Coupled between each of the power lines is a capacitor for shunting high frequency components of the power between the lines.

Ferroelectric imaging system

Abstract: An improved ferroelectric imaging system comprises a chopper, lens system, ferroelectric detector matrix, switching matrix, temperature controlled heat sink, drive and read out electronics, video processor and display. The chopper interrupts infrared energy emanating from a scene, and the lens system focuses the chopped infrared energy on the ferroelectric detector matrix which produces electrical signals representative of the infrared energy impinging thereon. The signals are read out by the drive and read out electronics whose action is synchronized with the chopper action, processed in the video processor and displayed by the display. The ferroelectric detector matrix comprises a plurality of detector capacitor elements whose top plates are formed by conductor stripes longitudinally disposed on a dielectric of ferroelectric material and whose lower plates are a plurality of metal pads formed on the dielectric. The switching matrix includes a plurality of solid state switches operatively connected to the lower plates of the detector capacitor elements, a bias source, and drive and readout electronics. The address means operates the switches for selectively charging corresponding detector capacitor elements, and reading out the electrical signals representative of the impinging infrared energy, whereby shunt capacitance between each capacitor in a charged column and each capacitor in an adjacent noncharged column is alleviated and fixed pattern noise is eliminated.

Series feed-through capacitor

Abstract: Feed-through capacitor of the type for use in filters and the like and including discoidal ceramic capacitors arranged in stacked relationship and electrically connected in series. Series arrangement of the discoidal capacitors prevents shorting through the feed-through capacitor in the event of failure of one of the discoidal capacitors therein and results in substantially improved insertion loss characteristics when compared to feedthrough capacitors having a single discoidal capacitor.

Electrostatic generator and motor

Abstract: Method and apparatus for electrostatically generating power by converting random mechanical motion into electrical energy. The apparatus includes two variable capacitors that have their capacitances varied in an alternating manner by the physical displacement of a common conductor that forms one plate in each of the capacitors. The variable capacitors are formed in a container which holds a fluid for increasing the output power of the apparatus. The fluid in combination with movable conductor also generates sufficient charge to bias the variable capacitors.

Low temperature fired ceramic capacitors

Abstract: A multi-layer ceramic capacitor is characterized by a ceramic composition including barium titanate and lithium fluoride as essential ingredients resulting in the capability of sintering the composition at temperatures below 1100° C. As a consequence, the electrodes for the capacitor can be formulated from pure silver or a silver palladium composition in which the major component is silver thereby decreasing the expense of such capacitors as compared to those requiring platinum, gold, or mixtures of these precious metals and/or similar precious metals in making up the electrodes.

How to improve system stability without risking subsynchronous resonance

Abstract: Various static devices for raising the stability limit of a power system are examined with respect to their employment at or near the electrical center of a two-machine system. Among these devices are series capacitors, shunt capacitors, combined series and shunt capacitors, and shunt static reactive compensators consisting of a fixed capacitor and a variable reactor. New concepts of current gain, voltage gain, and power gain are defined and illustrated. The natural frequencies of each circuit are examined, and it is shown that with series capacitors these frequencies are subsynchronous and hence produce a risk of subsynchronous resonance, whereas all shunt-connected devices give supersynchronous natural frequencies and therefore do not involve such a risk.

Random access MOS memory cell using double level polysilicon

Abstract: A cell design for an MOS random access memory is disclosed. Two levels of polycrystalline silicon are used, one for the bias voltage side of the storage capacitors and another for the gates of the MOS transistors and as the bit select line or to connect the gates to the bit select line. The bit select or X address line may overlie both the first and/or second level poly, so space is saved in the cell layout. A "V-groove" anisotropically etched storage capacitor may include the MOS access transistor in one end, formed by double implant.

High field capacitor structure employing a carrier trapping region

Abstract: OF THE DISCLOSURE A high field capacitor structure includes an insulating layer having a carrier trapping region between two electrodes.The trapping region improves electric breakdown characteristics of the capacitor structure and is particularly useful in avoiding the low breakdown voltages and high leakage currents normally encountered in structures with asperities, such as SiO2 over poly Si. The trapping region can be formed by chemical vapor deposition (CVD) process, by evaporation or by ion implantation. The trapping region is close to the Si, but far enough away to eliminate the possibility of reverse tunneling from discharging the traps in the absence of an applied voltage.

Electrical energy conversion systems

Abstract: Electrical circuits, apparatus and methods for a variety of applications. A switching device subdivides an alternating current input signal into a plurality of lower voltage pulses by switching on and off in response to the characteristics, such as the voltage and current, of the input signal, and the pulses of current are intermittently passed to a capacitor in series with the device as the voltage on the input signal is positive-going. When the voltage becomes negative-going, the capacitor is discharged, usually with the pulses passing through the switch in the opposite direction. Work is done by energizing the series capacitor, or by energizing a capacitor in parallel with the switch, or by energizing an inductor in parallel or series relation to the switch, or a combination of the above. The inductor may be the primary winding of a transformer, or may create an electrical or magnetic field which is transduced into mechanical motion. The load may also be a resistive load. Where a tranformer is provided, the output of the secondary may be used as a power supply, with or without additional filtration. The transformer may have a unity turns ratio, or may step the voltage up or down as desired. Where the device is used as a power supply, and in other applications, a direct or alternating current output is provided which can be very carefully controlled as to voltage with minimum circuitry being necessary to accomplish this purpose.

Carrier current communications system

Abstract: A plurality of transmitters and receivers arranged for carrier current communications are generally placed throughout a large building. The transmitters and receivers are coupled to selected portions of the power distribution system. The selected portions are stairwell exit and lighting risers emanating from the same location of contiguous circuit breakers. Coupling circuits are applied to both remote transceivers and the central station transceivers. These circuits insure that remote station receivers always present high impedance to the power line at the carrier frequencies and that remote transmitters do not load the lines. At the central station, a bridge arrangement of the networks couples energy to and from the lines, with additional isolation between receiver and transmitter circuits. Mutual interference of transmitted and received signals are avoided by taking advantage of the impedance in the length of line from the central station to coupling and line conditioning circuits, and capacitor tuning to the center frequency of the transmitter line and to the center frequency of the receiver circuits. Low impedance at the common bus allows the signals to be readily transmitted to the risers.

A simple voltage controlled oscillator with grounded capacitors

Abstract: A simple voltage controlled oscillator circuit using capacitors, all of which are grounded, is presented. The circuit is thus attractive from the point of view of monolithic or hybrid IC fabrication. The frequency of oscillation can be varied over a wide range, with the amplitude of oscillation remaining relatively stable over the range. Experimental results are given that agree closely with the theoretical predictions.

Energy saving device for a standard fluorescent lamp system

Abstract: There is provided in combination with a rapid-start series-sequence type ballast for two low-pressure mercury discharge lamps, apparatus for reducing the power consumption of both lamps. The apparatus utilizes switch means in conjunction with a capacitor to limit the current supply to the lamps after the lamps are energized. The switch means has two members in series circuit arrangement with one of the electrodes of one of the lamps. Each member is connected on opposite sides of the electrode. The capacitor is connected in parallel circuit arrangement with one of the members. Initially upon energization the switch means has a low impedance state to permit current flow and then switches to a high impedance state. The switch means permits preheating of the electrode and thereafter upon response to current flow switches and causes the lamp current to pass through the capacitor and thereby decrease by a predetermined amount the current through the normally operating lamps. The switch means may comprise switch members having a positive temperature coefficient of electrical resistance.

UHF electronic tuner

Abstract: A high input selectivity UHF varactor tuner for a television receiver in which unamplified radio frequency signals are inductively coupled to a double tuned half-wave preselector comprising two aperture coupled half-wave tuned lines in separate resonant cavities. The double tuned preselector includes varactor diodes on one end of each tuned line and fixed capacitors on the other end of each line. To compensate for decreasing Q of the varactor diodes with decreasing frequency and thereby maintain a uniform bandwidth for the tuner over the entire UHF spectrum, inductive coupling is provided between the tuned lines at the fixed capacitor ends which, during low frequency operation of the tuner, augments aperture coupling between the lines.

Over-current protection circuit for voltage regulator

Abstract: A control transistor in the over-current protection circuitry of a voltage regulator is connected in a regenerative latch circuit with a complementary-conductivity auxiliary transistor, whereby conduction once initiated in said control transistor tends to be sustained. This avoids the tendency towards rapid oscillation between shut-down and power-up conditions in the over-current protection circuitry. The regenerative latch circuit loads the capacitor that supplies its sustaining current so heavily that the potential thereacross decays, the decay finally advancing to the point where regeneration halts. The resulting non-conduction of the control transistor permits the voltage regulator to attempt to resume the power-up condition. The present invention is an improvement in such a voltage regulator wherein circuitry is provided for rapidly recharging the capacitor for supplying sustaining current during this attempt. The recurrence of this cycle during short-circuit loading conditions leads to a relaxation oscillator mode of operation with the power-up duty cycle being sufficiently low that the components of the voltage regulator are kept from being damaged by overheating.

Ceramic capacitor having a silver doped dielectric of (Pb,La)(Zr,Ti)O{HD 3 {B and glass

Abstract: The dielectric material of a ceramic capacitor contains a high temperature silver doped ceramic with a small proportion of a low temperature glass. The ceramic component consists essentially of a lead zirconate in which from 0.07 to 0.16 molar parts of the lead are replaced by lanthanum and in which from 0.10 to 0.40 molar parts of the zirconate are replaced by titanate. The capacitors may be fired in an air atmosphere without substantial loss of lead at temperatures as high as 2000 DEG F. Silver containing electrodes may be employed in a monolithic capacitor of this invention, the co-fired electrode advantageously causing a silver doping of the ceramic that in turn improves the stability of capacitance with temperature and applied voltage. Alternatively, the ceramic may be predoped with silver to achieve this result.

Linear exposure control system

Abstract: A magnification signal of 64 - 100% is applied as an input parameter to a specially designed relaxation oscillator which produces a pulse train wherein the pulses thereof have a duration which vary in linear fashion with respect to the magnification input signal, the relaxation oscillator employing a constant current source in series relationship with an integrating capacitor which produces a saw tooth signal having a slope which is constant regardless of variations in the amplitude of the magnification input signal. The output pulses from the relaxation oscillator are counted to define an exposure control interval which changes linearly with respect to the input magnification signal.

Structure and technique for achieving reduced inductive effect of undesired components of common lead inductance in a semiconductive RF power package

Abstract: An RF power transistor device, or package, which includes a transistor, a capacitor, an electrically insulating but thermally conducting substrate, a metallic ground lead member on the substrate having input output and common portions, a heat sink on which the substrate is mounted and, input and output microstrip conductor means mounted on the heat sink has the common lead inductive effect of at least one component of common lead inductance of the transistor reduced by tightly coupling the input ground current and the input current as by a film of dielectric material such as Kapton or Teflon of about one half mil in thickness. Alternatively the output current and the output ground current may be tightly coupled.

Frequency and temperature tests for lateral nonuniformities in MIS capacitors

Abstract: Interface states and lateral nonuniformities produce very similar abnormalities in the C-V curves of MIS capacitors. Two C-V techniques are presented here to aid in distinguishing between them. The first technique is based on the frequency dependence of the interface-state capacitance and utilizes the resulting frequency dispersion of the "high-frequency" capacitance in the depletion regime, which occurs in a frequency range typically between a few hundred Hz and 1 MHz. The second method utilizes a freeze-in of carriers in the interface states at liquid nitrogen temperature. A sweep of bias from accumulation into deep depletion at low temperature produces a C-V characteristic which, when compared with the corresponding ideal characteristic for the same semiconductor doping profile, reveals the presence of lateral nonuniformities. A complementary test is provided by temporary illumination of the deep-depleted structure followed by a sweep of bias from inversion into accumulation. A ledge in the C-V characteristic reveals the presence of interface states in the central half of the bandgap.

Package for push-pull semiconductor devices

Abstract: A semiconductor package for containing two individual devices such that they may be externally connected in a push-pull relationship. Two transistors, each having an input and output pad are formed on the same dielectric wafer, in a spaced relationship with each other and a ground plane so as to form two separate transmission line paths. The transistors are wired either in a grounded emitter or grounded base configuration. A shunt inductor is formed by a metallized strip or lead bond from the collector of one transistor to the collector of the other transistor. This inductor reduces the influence of the parasitic capacitance in the equivalent output circuit of the transistors. Since the collectors of both transistors are at the same DC level it is not necessary to include a DC blocking capacitor in series with the inductor. This increases the reliability and the reproducibility of the circuit because bonding wires necessary in prior devices to connect the blocking capacitor in series with the output inductance is not necessary. This packaging technique increases the output impedance, decreases the internal losses, and increases the bandwidth when wired as a push-pull circuit.

Charge coupled device filters and modems incorporating such filters

Abstract: A Modem utilizing process technology compatible CCD and IGFET circuits and sub-systems incorporated on a single I.C. chip. CCD transversal filters are employed as bandpass filters, being tuned for different modes of operation by adjustment of the clock frequency. The bandpass filters are operated in conjunction with a charge amplifier to remove d.c. offset from the analog output of the filters. The demodulator section of the Modem also incorporates low-pass filter employing switched resistors. The modulator section includes waveform generators based on a digital-to-analog converter including switched capacitors having values selected such that a sine wave having minimal distortion is generated when switched in proper sequence. Provision is made for digital inputs to control the frequency and amplitude of the sine wave output. The Modem can be operated under control of a microprocessor.

Fuel ignition control system

Abstract: A fuel ignition control system including a control arrangement for operating pilot and main valves of the system the pilot valve being operated to permit a pilot flame to be established, and the main valve being operated by a pilot flame sensing circuit which includes a controlled switching device enabled in response to the charging of a capacitor to a given value to effect the operation of the main valve, the charging of the capacitor being controlled by a further controlled switching device which supplies AC current to the capacitor in the absence of a pilot flame, preventing the capacitor from charging to the given value, and which supplies DC current to the capacitor when a pilot flame is established, permitting the capacitor to charge to the given value. In an embodiment wherein the main valve is energized by a relay controlled by the flame sensing circuit, the control arrangement includes an interlock arrangement which prevents start up of the system under certain failure conditions, such as welded relay contacts. In another embodiment, the system includes an igniter circuit which has a flame responsive enabling circuit which permits the igniter circuit to be enabled and disabled independently of the flame sensing circuit.

Novel hybrid packaging scheme for high density component circuits

Abstract: A hybrid solid state package in which integrated circuits, precision resistor networks, capacitors and their interconnections are accommodated on a multi-layer process substrate while thick film resistors and interconnections provided on a separate substrate, which sub-assemblies are then sandwiched together using film epoxies are inserted within a single package, to thereby yield a structure of significantly smaller size and lighter weight and having minimal number of input-output interconnections as compared with conventional designs and without impairing quality or reliability.

Ceramic capacitor having a bismuth-containing silver-doped dielectric of (Pb,La) (Zr,Ti)O3

Abstract: The dielectric material of a ceramic capacitor contains a high temperature silver doped ceramic with either no glass or with a small proportion of a low temperature glass. The ceramic component consists essentially of a lead zirconate in which from 0.07 to 0.16 molar parts of the lead are replaced by lanthanum and in which from 0.10 to 0.40 molar parts of the zirconate are replaced by titanate. The capacitors are preferably fired in a closed atmosphere at temperatures from above 2000° F to 2200° F. Silver containing electrodes may be employed in a monolithic capacitor of this invention, the co-fired electrode advantageously causing a silver doping of the ceramic that in turn improves the stability of capacitance with temperature and applied voltage. Bismuth trioxide is added to the green ceramic body that permits a lower firing temperature or is included in the glass formulation, in both cases the bismuth serving to accelerate a silver reaction with the ceramic at firing.

Terminal-cover assembly having coined region of reduced cross section compressing resilient bushing

Abstract: A metal cover has a hole into which an insulating resilient T.F.E. bushing is force fitted. A metal terminal is pushed into the hole in the bushing. These three parts are essentially coaxial and form a cover-terminal assembly that is subsequently placed between and compressed by a pair of coining dies to deform the cover metal adjacent to the periphery of the cover hole. This coining step forces metal tightly against and into the resilient bushing subsequently compressing the bushing about the terminal. This terminal-cover assembly is particularly suitable for closing the housing of a hermetically sealed electrolytic capacitor. It is inert to chemically active electrolytes and withstands high internal pressures that are often associated with such capacitors.