Abstract: Disclosed is a capacitance level measuring device comprised of a container whose level is to be measured and a probe inserted into and spaced from the container. The capacitance between the probe and container varies in relation to the level in the container. A capacitance measuring circuit determines the capacitance between the probe and container and thus indicates the level in the container. The integrity of the probe is verified by constructing the probe so as to include it in a series circuit, as well as the capacitance measuring circuit, and a lack of continuity in the probe is indicative of questionable probe integrity. The question as to the probe's integrity would indicate a questionable level indication from the capacitance measuring circuit. Various probe constructions are also disclosed.

Abstract: A capacitance intrusion detection system for use with a metal object or objects insulated from ground comprises a circuit for cyclically charging and discharging the object at a relatively low frequency, for example, less than 500 Hz, and simultaneously integrating the charge on the object to develop a DC voltage proportional to the capacitance of the object. The integrating network is AC coupled to a bandpass filter which passes signals having frequencies corresponding to changes in capacitance of the object caused by an intruder and these signals are applied to a threshold circuit for activating an alarm when an intrusion occurs. Tamper alarm circuits are provided to detect unauthorized disconnection of any portion of the protected object (decrease capacitance) or the addition of capacitance in an attempt to defeat the system.

Abstract: Apparatus and method for converting heat to electrical energy by the use of one or more capacitors having temperature dependent capacitance. The capacitor is cycled between relatively high and relatively low temperatures by successive thermal contact with relatively high and relatively low temperature portions of a heat transfer medium having a temperature gradient therein. Upon heating of the capacitor, the capacitance thereof is reduced, so that a charge therein is caused to expand into associated external circuitry in which it is available to do electrical work. The capacitor is then cooled and recharged and the cycle is repeated. The electrical output of the capacitor results from the regenerative delivery of heat to and removal of heat from the capacitor by the heat transfer medium, and efficient conversion of heat to electric energy is thereby effected.

Abstract: A carrier for LSI chips includes a built-in capacitor structure in the carrier. The capacitor is located beneath the chip with the plates of the capacitor parallel to the chip mounting surface or at right angles to the chip mounting surface. The capacitor is formed by assembling an array of capacitive segments together to form the first one of the plates of a capacitor with the other plate spanning a plurality of the segments of the first plate. Each of the segments of the first plate includes a set of conductive via lines which extend up to a severable link on the chip mounting surface. The severable via is cut by means of a laser beam or the like when the capacitor must be repaired by deleting a defective segment of the capacitor. Preferably, the structure includes a pair of parallel conductive charge redistribution planes above and below the capacitor plates with connections to the respective plates providing a low inductance structure achieved by providing a current distribution which results in cancellation of magnetic flux. The lower redistribution plane is preferably connected directly to the lower capacitor plate. The upper redistribution plane is preferably connected to the segments of the first capacitor plate by means of the vias which extend first to the chip mounting surface and then down to the redistribution plane which has connections to the chip mounting pads.

Abstract: A force sensing means comprising capacitor plates in the form of metallic cloth bonded to a compressible dielectric made from a foamed elastomeric material. An incompressible layer of insulating material may be formed over one or both of the capacitor plates and additional capacitor plate or plates may be provided bonded to the insulating layer to shield the capacitor plates bonded to the compressible dielectric. The metallic cloth strips forming the capacitor plates may be formed in the form of strips running crosswise on opposite sides of the dielectric to provide a matrix of force sensing means. The warp and weft threads of the metallic cloth are arranged so that neither is perpendicular or parallel to the longitudinal direction of the strip.

Abstract: The functional relationship between dielectric constant and soil content has been applied to the development of a dielectric soil water moisture meter based on converter capacitance-frequency. A measured capacitance forms part of the tuning capacitance of an oscillator and causes a definite frequency deviation. A cylindrical probe fitted with an oscillator is used to measure the electrical field. The author has determined the basic characteristics of the instrument—center of sensitivity, radius of the electrical field, and influence of soil properties, particularly changes in bulk density, chemical composition, and temperature. The device is applicable for either continuous use, with the probe permanently built in to the soil layer, or use with the probe sliding inside an access tube, in which case the vertical distribution of soil moisture is measured. Field calibration of the meter is required.

Abstract: A capacitance type displacement conversion device is provided in which a physical displacement resulted from a change of a physical value such as pressure or tension is converted into an electrical signal. The device is comprised of a capacitance sensor and an improved circuitry whereby conversion characteristics are linear and free from erroneous measurements caused by distributed capacitances and other circuit elements related thereto. The type of the sensor may be either a single capacitance or a differential capacitance type.

Abstract: The paper deals with an instrument which has been developed for the measurement of moisture content in concrete and soil. A parallel-plate capacitor has been used as the sensing transducer. The instrument is compact, reliable, inexpensive, and gives consistent results over an extended life-testing period.

Abstract: A reference capacitor is coupled in parallel with a capacitor of which the size thereof is variable and an oscillator is used to alternately charge and discharge both capacitors between first and second voltage levels. The absolute magnitude of the current flowing through the reference capacitor, which varies in proportion to the size of the variable capacitor, is detected which is indicative of the variations in size of the variable capacitor. If the variable capacitor is disposed in the fuel tank of a vehicle, water in the fuel will cause the effective capacitance value of the capacitor to increase which reduces the absolute magnitude of the current that is detected. The absolute magnitude of the detected current can be utilized to indicate excessive water levels in the fuel.

Abstract: An improved capacitor and a method of manufacturing the same, aimed at implementation in small size and/or with large capacitance, are disclosed. A pair of composite structures are formed. Each composite structure includes insulating layers of ceramic material formed on a base plate of a flexible material. At least one electrode is formed on the insulating layer. A dielectric layer of a ceramic green sheet of extremely small thickness, as thin as approximately 3 microns, is formed on the insulating layer covering the electrode. The two composite structures are joined to form a laminate such that respective base plates are located on the outside of the resultant laminate and the respective electrodes face each other through respective extremely thin dielectric layers. The resultant laminate is fired in a heating furnace after the respective base plates are removed. As a result, a capacitor is formed whose electrostatic capacitance is defined between the two electrodes.

Abstract: PURPOSE:To form a vertical type buried capacitor having large capacitance value by sequentially laminating an insulating layer, the first conductive layer, a dielectric layer and the second conductive layer on the region to be formed with a capacitor at the grooved hole formed on a substrate. CONSTITUTION:Grooved holes 4 are formed on an Si substrate 1, and an insulating layer 5 is covered on the surface of the hole 4 and the region to be formed with a capacitor on a semiconductive layer. The first metal thin layer 6 of Ta, a dielectric layer 7 of Ta2P5, the second metal thin layer 9 of Al, Ta are sequentially laminated therein, and a capacitor is formed with the first layer, the dielectric layer and the second layer. In this manner, the surface area of the capacitor per flat area can be increased, thereby obtaining a large capacitance value by enhancing the dielectric constant.

Abstract: A sawtooth wave oscillator is disclosed which includes a series connection consisting of a charging circuit and a first capacitor, a voltage dependent capacitor connected in parallel to the first capacitor, and a discharging circuit connected in parallel to the first capacitor, whereby a sawtooth wave which has good linearity can be generated with a simple circuit construction.

Abstract: A ratio transformer method suitable for the measurement of the dielectric constant of highly conducting liquids is described. The resistance between the two plates of the capacitor can be as low as 2 k Omega . In this method variations in this low resistance will not give any error in capacitance measurement. One of the features of this method is the simplicity in balancing the resistance, using a LDR (light dependent resistor), without influencing the independent capacitance measurement. The ratio transformer enables the ground capacitances to be eliminated. The change in leakage inductance of the ratio transformer while changing the ratios is also taken into account. The capacitance of a dielectric cell of the order of 50 pF can be measured from 1000 Hz to 100 kHz with a resolution of 0.06 pF. The electrode polarisation problem is also discussed.

Abstract: The distance-frequency transducer includes a capacitor whose capacitance changes as a function of movement of one electrode relative to the other. The movement is controlled by the parameter to be measured, as, for example, the pressure in a pressure pickup. The capacitance determines the frequency of an RC oscillator. The output frequency of the oscillator can be calibrated directly in pressure units.

Abstract: The circuit of a primary element capacitor is energized and arranged to produce a proximity signal not substantially affected by the conductivity of fluid-like material accumulated on the capacitor structure. The energization, circuit components, and capacitor insulation minimize the electrical characteristics of the material accumulation on the capacitor.

Abstract: 1. Process for the overswing-free switching-on and switching-off of a capacitance (3) lying in series with an inductance between two conductors (1, 2) of an alternating current voltage circuit, by means of a switch (5) lying in series with the capacitance, with the following process steps : a) by the short-term closing of the switch (5) the capacitance is charged from the voltage (Uw ) between the conductors (line to line voltage) in a semi-oscillation to the peak value of the operative capacitance voltage, b) the charged capacitance (3) is switched-on by closing the switch (5) when the voltage at the switch reaches a minimum, c) for switching-off the capacitance (3) the switch (5) is opened during zero passage of the current flowing through the switch ; and d) after opening the switch the capacitance is discharged, characterized by the following features : e) discharging of the capacitance (3) is effected uncontrolled according to a discharging characteristic (resistance 10), the time constant of which is a multiple of the alternating current voltage period, and f) for the capacitance charging the closing moment of the switch (5) (charging closing angle), with respect to the alternating current voltage from the mains, is determined in dependence on the voltage (Uc ) at the capacitance in such a way that even when there is a residual capacitance voltage still present, charging is effected to the peak value of the operative capacitance voltage.

Abstract: Method and apparatus for testing pairs of conductors of a telephone cable, including method and apparatus for measuring the capacitance of a circuit component such as a pair of conductors. The capacitance of each of twenty-five pairs of conductors of a cable is measured and the capacitance value is stored, the median value of capacitance is identified and stored, each measured capacitance value is compared with the median value, and an out-of-limits indication is made when a measured capacitance value deviates from the median value by more than a predetermined limit. Capacitance is measured by connecting the circuit component, such as a pair of conductors, in the timing circuit of a monostable multivibrator, charging and discharging the timing circuit to vary the elapsed time of the on output of the multivibrator. The multivibrator controls the output of an oscillator and the oscillator output pulses are counted, with the count total varying as a function of the capacitance of the conductor pair. The instrument may be calibrated to read out directly in capacitance if desired.

Abstract: A capacitance sensing device for detecting the amount of material flowing through a passage includes layers of disk-shaped insulating substrates having electrode films formed on surfaces thereof facing each other, and the insulating substrates are supported by an insulating support member as a unit and spaced from each other. The electrode films are alternately connected by a pair of conductors to form a capacitor. Electric circuit elements, forming a detection circuit which is connected to the pair of conductors and which detects a change in capacitance of the capacitor depending on the amount of material flowing through the spaces between the electrode films, are formed on the outer surface of an outermost one of the substrates in a form of a monolithic circuit or a hybrid circuit.

Abstract: PURPOSE:To measure a leakage current accurately by testing conduction between a measuring probe and a contact checking probe which is added to the measuring probe. CONSTITUTION:A measuring power source E is connected to the capacitor 2 to be tested. A measuring probe 7 and a contact checking probe 8 are connected to a lead 5 of the capacitor 2 to measure a leakage current with a current- voltage conversion circuit 6 which inputs the results to a decision circuit 11. Then, the probes 7 and 8 are switched with a switching circuit 9 and led into a contact checking circuit 10, which checks for the conduction in the route of the probe 7 the lead 5 the probe 8 and the results are inputted into the decision circuit 11. Depending on the outputs (a) of the circuits 6 and 9, the circuit 11 determines the quality of the capacitor 2. This prevents misjudgement due to poor contact of the probes.

Abstract: A new type of capacitance displacement measuring system has been developed. The gage is directly attached to the specimen for measurements at elevated temperatures. This system has been successfully used in materials testing at temperatures up to 600°C with excellent repeatability and resolution in strain in the 10−6 range. Good temperature stability of the entire system is required to achieve the reported capabilities.

Abstract: Electrical properties of the large-capacitance multilayer ceramic capacitor made of the ceramics of Pb(Fe2/3W1/3)O3–Pb(Fe1/2Nb1/2)O3 system were studied. The ceramics are sintered at 900°C in air, and therefore, it is possible to use Ag–Pd alloy as the internal electrode. The size of the capacitor with capacitance of 400 µF is fairly small. Dissipation factor is extremely small (0.6%) under the D.C. voltage bias in wide frequency range. Insulation resistance is more than 6000 M Ω µF. Impedance at high frequency band is small compared with those of other electrolytic capacitors with the same capacitance. Electrical properties are hardly changed in lifetime test.

Abstract: The ceramic electrically tunable capacitor maintains the tuned value after switch off of the equipment. When manufactured, the capacitor has a definite long term value but can be electrically tuned back to another value over a certain range, this value can also be held during non-operational conditions. The capacitor is formed of several laminates (22-31) of ceramic material and between each laminate is an electrode layer (1-11). Alternate odd electrode layers (1,5,9) are connected to one (A) of the capacitor terminals and the other alternate odd layers (3,7,11) are connected to the other capacitor terminal (B) to form the complete capacitor. The even layers (2,4,6,8,10) which interleave are the control electrodes connected to a control terminal (C). The electrical potential applied to the control electrodes uses the ferro-electrical hysteresis properties of the ceramic to adjust the capacitor value. A typical value capacitor could be tuned from 6.7nF to 8.3nF by the application of 50 volts.

Abstract: A pulse shaping and amplifying circuit receives direct current electrical power from a source and serves to supply a pulse of electrical energy to a load. First and second switches (e.g., transistor switches) are interconnected such that only one is conductive at any one time. The first switch, when conductive serves to connect a capacitor which forms part of an oscillatory circuit, further including an inductor in the form of a transformer primary winding, to the source to place an electrical charge on that capacitor in a first direction. When the second switch is rendered conductive (and the first opened) the load is connected in circuit with the oscillatory circuit and the capacitor discharges to deliver a pulse of electrical power to the load with any excess power being utilized to charge the capacitor in the second direction. A flyback current path including a transformer secondary winding, closely coupled to the primary winding, and a diode is connected in parallel with the capacitor such that the capacitor again changes direction of charge to thus be charged in the direction for supplying the next pulse to the load. If desired, a second capacitor may be connected in parallel with the oscillatory circuit to improve the rise time of the pulse supplied to the load.

Abstract: PURPOSE:To decrease the number of elements and to reduce the size by detecting the voltage of a capacitor, charged according to the level of an input signal, through a Schmitt circuit composed of MOS transistors (TR), and thus discharging the capacitor CONSTITUTION:When an input signal VIN is applied to an input terminal IN, a gate voltage which corresponds to the signal VIN is applied to gates of MOSTRs M5 and M6, so a capacitor C is integrated by a current which corresponds to the signal VIN A Schmitt circuit 23 consists of MOSTRs M11-M15 When the potential of the capacitor C is low, the M11 is turned off and an output OUT has a high level When the potential of the capacitor C is higher than the output VB of a voltage switching circuit 232, the M11 turns on Then, the output OUT has a high level and the capacitor C is discharged through the M8 and M6 to hold the source voltage of the M11 at the earth potential because the M13 turns on, thereby turning on the M11 securely

Abstract: The press. sensor is partic. simple, robust and cheap in comparison with conventional press. sensors and does not contain any expensive material. It also produces active signals suitable for direct processing. A capacitor consisting of a dielectric (3) and two or more electrodes (1,2) is placed in the medium whose press. is to be measured. The active electrical signal produced by the press. acting on the capacitor arrangement is fed to an amplifier (8). The dielectric medium may be of plastic or ceramic material. The capacitor may be constructed as a disc or small tubular object and may be used for measuring the press. of an internal combustion engine, in which case it can be built into an ignition spark plug.

Abstract: : Monolithic Thin Film Bypass Filters consisting of one inductor and one capacitor have been fabricated using vacuum deposition techniques. The inductor and the capacitor are formed at the same time by depositing alternate layers of metal and dielectric materials. The inductor and the capacitor are interconnected to form a three terminal device. Two sizes of Bypass Filters, designated as LC-55 and LC-100 having inductance value ranging from 35 to 1,100 nanohenries and capacitance value ranging from 11.5 to 510 picofarads have been constructed. It has been shown that the values of inductance and capacitance of a Bypass Filter can be varied almost independently by changing the thickness of the dielectric deposited. Measurements of the electrical parameters of the inductor and the capacitor individually as well as the frequency characteristics of the device functioning as a Lowpass or Highpass filter have been conducted.

Abstract: A fixed value capacitor is designed for direct mounting within a slot in a printed circuit card. The capacitor has a rectangular cross-section that is made of alternate layers of a suitable ceramic dielectric and electrodes. Terminal strips are formed down both edges and project along the sides. The bottom end of the capacitor is tapered and sized to fit into a slot in a printed circuit card. A high capacitance to size ratio is achieved.