Abstract: A system for groves, truck farms and the like for automatically irrigating and fertilizing in accordance with the requirements of the soil. A plurality of capacitance sensors are buried in the areas to be irrigated and fertilized. A computer periodically measures the equivalent capacitive reactance of each sensor to obtain an indication of soil moisture and the equivalent resistance of each sensor to obtain an indication of fertilizer levels in the soil. Water pumps and valves and liquid fertilizer pumps are controlled by the computer to operate only when the soil requires.

Abstract: A polysilicon microstructure is formed on a silicon substrate. Beneath the microstructure, are diffused regions in the substrate. The microstructure is capacitively coupled to these diffused regions so that one such capacitor acts as an excitation capacitor and the other capacitor acts as a sense capacitor. By applying an AC voltage to the excitation capacitor, the electrostatic force between the substrate and the microstructure changes causing a mechanical vibration in the microstructure. A DC voltage is applied to the sense capacitor. The mechanical vibration, which changes its capacitance, will develop a current through the sense capacitor. A phenomenon may then be sensed by the vibrating microstructure. A polymer film disposed on the microstructure can sorb a gas of interest. As the mass of the polymer film and vibrating microstructure increases, its frequency or phase changes. The current through the sense capacitor will exhibit a commensurate frequency or phase shift. Detection of such frequency or phase shift in the sense capacitor current will transduce the detection of the vapor of interest.

Abstract: The invention provides a high voltage capacitor suitable for measuring the voltage of an overhead power line. The capacitor dielectric (16B) is mounted directly on to the power line conductor (2), which serves as one electrode of the capacitor. The other electrode (18) of the capacitor is mounted on to the outer surface of the dielectric (16B), and is protected at each side by a guard ring (20). Stress control (22, 24) is provided between the outer capacitor electrode (18) and the guard rings (20) and also at the outer edges of the guard rings (20). The capacitor may be enclosed in an earthed housing (30). which can contain one or more current transformers (34, 36, 38). The apparatus can be used for fault detection and location, and may be used in combination with a power cable or a switch.

Abstract: A method for adjusting capacitances in a monolithic integrated circuit wherein it is desirable that the capacitances form a binarily-weighted sequence of values includes sequentially-connecting trim capacitors in parallel with a primary capacitor and determining as each trim capacitor is connected, whether the resultant parallel capacitance is larger or smaller than that of a reference capacitance. If the resultant capacitance is too large, the trim capacitor is disconnected, but otherwise is left connected. The process is repeated until each trim capacitor has been tried. For the purpose of adjusting the capacitance of the next-largest capacitance, the final resultant capacitance is connected in parallel with the reference capacitance to form a new reference capacitance. The procedure is then repeated with the next-largest primary capacitor until the final resultant capacitance associated with each primary capacitor has been adjusted. In another aspect of the invention, capacitance-adjustment steps are sequentially interleaved with analog-to-digital conversions in an analog-to-digital converter.

Abstract: A high density integrated circuit structure, for example a dynamic memory cell, is described which includes an active/passive device in combination with a capacitor structure. The capacitor structure is of the polysilicon-oxide-silicon type and is formed on the sidewalls of a mesa-shaped and dielectrically isolated region of silicon material resulting from the formation of an isolation trench in the silicon. The trench is filled with a plastic material, such as polyimide. The capacitor is formed by the isolated region of silicon material which functions as the first capacitor plate, a doped polysilicon layer provided on the vertical walls of the mesa serving as the second capacitor plate and a thin dielectric layer interposed between the two plates serving as the capacitor's dielectric. Since the polysilicon is wrapped around the periphery of the mesa as a coating on the vertical sidewalls thereof, it gives rise to a large storage capacitance without an increase in the cell size.

Abstract: A capacitance membrane switch (1) of the type including (a) a variable capacitor defined by a first capacitor plate (64) on a flexible film layer (60) and a second capacitor plate (52) on a dielectric film layer (50) with an air gap therebetween, and (b) a fixed capacitor defined by the second capacitor plate (52) and a third capacitor plate spaced therefrom by the dielectric film layer (50), characterized in that: the third capacitor plate consists of conductive adhesive (47) bonded to the dielectric film layer (50) on a surface (59) thereof opposite from the second capacitor plate (52).

Abstract: A method for producing a capacitor includes the steps of: forming on a dielectric layer formed on a first electrode, an insulating composition, e.g., an organic polymeric compound containing a metal powder or an organometallic compound as a metal source, which is rendered conductive upon heating by radiation; and locally and gradually heating the insulating composition layer so as to form a second conductive electrode while measuring an increase in a capacitance between a conductor end portion for measuring a capacitance and the first electrode. According to this method, a capacitor having a precise capacitance can be formed.

Abstract: An integrated circuit capacitive transducer (10) measures at least one parameter of a medium to which it is exposed. A variable capacitor (12) has a capacitance (C1) which varies as a function of the measured parameter and is charged by source of reference potential (Vr). The charge on the variable capacitor (12) is then transferred to a second capacitor (14) having a fixed reference capacitance (Cr). The voltage (V1) developed across the second capacitor (14) by the charge transferred thereto is then a function of the capacitance (Vr) of the first capacitor (12). Therefore, the voltage (V1) is also a function of the parameter being measured. The capacitive transducer may also include a further variable capacitor (32, 34) for measuring the difference of parameters between two mediums.

Abstract: A liquid level measurement capacitance probe is disclosed comprising an elongated outer capacitor tube, an elongated inner tube coaxially mounted within the outer capacitor tube to form a capacitor annulus therebetween with the inner tube having a plurality of longitudinally extending capacitor elements cooperating with the outer capacitor tube to form a plurality of individual capacitor units, a connector unit for electrically connecting the capacitor units to an electronic circuit processor for measuring capacitance values of the capacitor units in calculating a fluid level, a filter for separating water from fuel flowing from the storage tank to be measured to the capacitor annulus, the filter having an annular housing mounted about the outer capacitor tube with an inlet port adapted for fluid communication with the storage tank, an outlet port connected to the capacitor annulus between the inner and outer capacitor tube for delivery of filtered fuel to the annulus, a water discharge outlet for discharging water from the filtered fuel, and a regulator for regulating the discharge of water through the discharge outlet into the storage tank to be measured, and a lower support housing mounted to the lower ends of the inner and outer capacitor tubes to support the lower ends of the capacitor tubes in coaxial spaced disposition.

Abstract: An elongated capacitance probe for use in a measuring system for locating a liquid level interface in a tank is provided. The probe includes an outer casing having first and second substantially semi-circular matingly engaging portions, the outer casing having top and bottom ends defining a length thereof approximately equal to a height of the tank. Spacers are mounted in opposed relation in the outer casing to form spacer pairs, the spacer pairs located in a spaced apart relationship along a longitudinal axis of the outer casing. A plurality of ground plates are mounted in a spaced apart relationship in the spacer pairs. To locate the liquid level interface in the tank, one or more capacitor plates are mounted in the spacer pairs, each capacitor plate mounted between a pair of ground plates, and extending substantially the length of the outer casing. Each of the capacitor plates in combination with a ground plate forms a capacitor extending substantially the entire length of the outer casing. An additional capacitor plate is mounted in the spacer pairs adjacent the bottom end of the outer casing for measuring an amount of water in the tank.

Abstract: A variable capacitance device generally intended for use in measuring the mass flow of air while passing through an engine-manifold The device is capable of responding to the impingement of a stream of air on its flexible capacitor plate located within an air conveying duct, in which the impingement tends to bend the flexible capacitor plate over the curved surface of a rigid electrically insulated capacitor plate The gradual bending of the flexible capacitor plate over the curved surface of the rigid capacitor plate changes the capacitance of the device at rate proportional to the rate of change in the mass-flow of the gas

Abstract: An apparatus for performing ratiometric capacitance measurements by comparing the output of a digital-to-analog converter with the voltage at a tap between an unknown capacitance and a first inherent capacitance of the apparatus. A common input voltage is supplied to both the series circuit, including the first inherent and unknown capacitances, and to the digital-to-analog converter which accomplishes attenuation of the input voltage in response to a digital value. The digital value is generated by a successive approximation register supplying a digital output relating the unknown capacitance to the known capacitance. The apparatus is adapted to ratiometrically measure the first inherent capacitance by supplying the common input voltage to a series circuit, including a known reference capacitance and the first inherent capacitance, such that the digital output of the successive approximation register relates the first inherent capacitance to the reference capacitance. The apparatus is further adapted to ratiometrically measure a second inherent capacitance by supplying the common input voltage to a series circuit, including the first and second inherent capacitances, such that the digital output of the successive approximation register relates the second inherent capacitance to the first inherent capacitance. The measured value of the unknown capacitance is then corrected by the amount of the second inherent capacitance appearing in parallel with the unknown capacitance during measurement thereof with reference to the first inherent capacitance.

Abstract: An on-chip capacitance measurement technique used for interline capacitances has been extended to MOS transistor capacitance measurements. The gate of the test transistor is connected to a reference capacitance made on the same chip. Small ac signals are applied to one of the transistor terminals successively. The magnitude of the ac voltages appearing on the gate node is measured indirectly. C/sub gd/,C/sub gs/ and C/sub gb/ are calculated accurately from the measured ac voltage and the reference capacitance value. It was found that C/sub gd/ and C/sub gs/, are measured completely free of parasitic capacitances resulting from both the internal on-chip circuit and external wiring. The on-chip circuit is simple and can easily be scaled down. These features insure this technique is the most suitable for the measurement of minimum-geometry transistors with atto-Farad-range resolution. It is shown that this technique has the ability to detect the capacitance difference which comes from the misalignment of source and drain metal connections. Measurements with this technique are used to first describe the short- and narrow-channel effects on MOS transistor capacitance.

Abstract: We have measured the electrical impedance of CdTe and Cd0.55Mn0.45Te crystals at temperatures between 82 and 104 K using frequencies between 20 kHz and 2.0 MHz. From the capacitance results we determined that the dielectric constant was only slightly smaller for x=0.45 than for x=0—a result important for the understanding of electromechanical coupling in Cd1−xMnxTe.

Abstract: An information input output display device comprising a dielectric (6,20) which is held in a portion between one electrode (18) and an other electrode (19) opposite to each other and which has at least a first state and a second state of unequal capacitances, means (7,8;25,26) to change the capacitance of the dielectric, capacitance holding means (11) to hold at least temporarily a value of the capacitance of the dielectric in the first state, and means (12) to compare the value of the capacitance of the dielectric with the value of the capacitance held by the capacitance holding means (11), whereby information can be read out without being affected by fluctuations in a distance d between the electrodes oriand in an ambient temperature T.

Abstract: PURPOSE: To widen the pass band width and also to obtain a wide tuning range by utilizing a distributed coupling of parallel lines having a flat frequency characteristic so as to realize the inter-stage coupling and applying the input/ output coupling while the capacitance is varied in response to the resonance frequency by means of a variable capacitive element. CONSTITUTION: The resonator is subjected to the distribution coupling at the parallel part of strip ring resonators 103, 104, the coupling between the inputs/ outputs is taken by varactor diodes 109, 110, and the coupling capacitance is changed from a control terminal 120 in response to the tuning frequency, that is, the coupling capacitance is controlled to be larger when the frequency is lower and to be gradually smaller as the frequency gets higher. Since the coupling capacitance is smaller than the tuning capacitance in the order of one digit, the same varactor diode cannot be used, but an element whose C(v)/Cmin is nearly coincident with respect to the impressed voltage is preferred, where C(v) is a capacitance at a voltage V and Cmin is a capacitance with the maximum impressed voltage. In this case, it is possible to make voltages V c1 and V c2 identical with the optimized circuit design. That is, the circuit is realized without using separate voltage to control terminals 120 and 121. COPYRIGHT: (C)1987,JPO&Japio

Abstract: A PNPN switch device with a circuit for preventing an error due to a surge voltage. The circuit comprises two capacitors. The first capacitor is formed in a P-type gate region. The second capacitor of a capacitance of an insulation layer sandwiched between a MOS gate electrode and a capacitor electrode is provided outside the P-type gate region.

Abstract: The invention provides a novel attachment for a discoid capacitor and the like to the inside of a tubular casing and to a central lead. An electrically insulating sealing element is positioned below the capacitor during assembly vertically into the casing. The element fits closely about the lead and is deformed into contact with the wall of the housing about the capacitor. The element thus forms a dam to contain solder and flux used to couple the capacitor to the lead and to the casing from above the capacitor so that the solder and flux cannot pass by the capacitor into undesirable locations below the capacitor.

Abstract: A high-voltage stabilizing circuit for stabilizing high voltages such as those generated by the fly-back transformer of a television. The stabilizer includes a common-emitter type PNP transistor and an inverse current-absorbing capacitor with a small capacitance in order to provide a high-speed response. The collector of the transistor is connected with the primary coil of the fly-back transformer and the capacitor. The emitter of the transistor is connected with a power source. With this arrangement, even though parabolic wave voltages are generated at the capacitor due to the small capacitance, the PNP transistor hardly cuts off at all and can therefore supply adequate current to the fly-back transformer.

Abstract: The invention relates to an ultra-high frequency oscillator operating in the X band. The oscillator circuit comprises a common gate-connected field effect transistor. The source connected tuning circuit comprises a variable capacitor of the varactor type controlled by a voltage and a choke in parallel. The control voltage is decoupled from earth by a capacitor. According to the invention, the transistor, the varactor and the capacitor are integrated into the same box or case in the form of a micromodule. The capacitor acts as a base for the transistor and the varactor, which are welded in juxtaposed manner. The length of the connection between the varactor and the source of the transistor has a minimum value, which makes it possible to broaden the linear frequency band as a function of the control voltage.

Abstract: For a measurement pick up in accordance with the principle of the differential capacitor, a circuit arrangement (Figure 1) is proposed which, building on a relaxation oscillator of an integrator (1) and a comparator (2), transforms the capacitance ratio C1/C2 of the measuring capacitor (3/4) into the duty ratio of a square wave oscillation, which can be evaluated by simple digital means and which is the output signal of a step-down frequency converter (6). This is achieved by the output signal of the comparator (2) alternating switching the part-capacitors (3 or 4) of the differential capacitor as integration capacitor of the integrator (1) via the step-down frequency converter (6) and an electrical switching element (5) (Figure 5).

Abstract: Electrical connections (16, 17) between the electrodes of a capacitor body (10) and electrical connections (18, 19) of the capacitor are produced from metal clamps which are aligned essentially parallel to one another and in a line in order to form an electrical parallel circuit and to reduce the inductance of the capacitor.

Abstract: not available for EP0069352Abstract of corresponding document: US4523938An optical fiber, being drawn from a preform and wound upon a reel, passes between parallel plates of a capacitor connected in a measuring circuit which, from the capacitance variations due to changes in fiber diameter, controls a reel-driving motor to minimize these variations. The capacitor may have a constant charge, as by having one of its plates made of an electret, in which case the capacitance variations are determined from voltage changes. A calculator connected to the measuring circuit translates these variations into numerical values representing the fiber diameter which can be visually displayed.

Abstract: A capacitor coupled circuit includes a power supply switch for switching power supply on; a coupling capacitor provided in a signal line; and a control circuit arranged to cause the capacitor to be charged or to be discharged in a short period of time according to the operation of the power supply switch. The arrangement enables the capacitor coupled circuit to obtain a stabilized constant output voltage in a short period of time after the power supply is switched on.

Abstract: not available for EP0040765Abstract of corresponding document: US4401942A monitoring system for a capacitor battery, the capacitor battery having a plurality of parallel legs, each with a plurality of sectional capacitors connected in series with fuses. Adjacent ones of the sectional capacitors are connected to one another by continuous cross lines. Electronic simulation circuitry is provided for producing a signal corresponding to the fundamental frequency component of a simulated capacitor voltage. A transient comparator circuit compares the fundamental frequency component of the simulated capacitor voltage with the fundamental frequency component of a measured capacitor voltage. Only rapid changes between the simulated capacitor voltage and the measured capacitor voltage are signaled as indicative of failures of one or more sectional capacitors in the capacitor battery. Slowly occurring voltage changes, which may correspond to variations in ambient temperature, do not lead to fault signaling.

Abstract: A capacitance detector for detecting the information recorded in the form of a series of microscopic pits on a capacitance disc record. The detector comprises, within an outer conductor, a dielectric support, an oscillator having a first line conductor on the support for generating microwave energy, a coaxial resonator having a second line conductor on the dielectric support, the second line conductor being coupled to the electrode of a capacitance detection stylus. Means are provided for inductively coupling the microwave energy from the oscillator to the resonator. This coupling means comprises a loop having a first section inductively coupled with said first line conductor and a second section inductively coupled with said second line conductor, and a capacitor connected from an intermediate point between the first and second sections to ground, so that the microwave energy coupled to the second line conductor is modulated in amplitude with capacitance variations corresponding to the microscopic pits. An amplitude demodulator is provided for demodulating the amplitude-modulated energy to derive a signal representing the capacitance variation on the record.

Abstract: Sensors and other electronic components often require the total capacitance to be matched after completion of all the mechanical work. The capacitive matching can be carried out in a non-destructive manner, without further mechanical treatment and with the desired accuracy and stability by means of a suitable layer which is deposited to the respectively required extent on a suitably shaped base capacitor, for matching. At the same time, the material of the layer can take into account view points relating to the application. A plunger-type body is advantageous for fine adjustment of the capacitance of hollow capacitors.

Abstract: The device with a digital display connected downstream of it has, as the pick-up for the rotational motion, a capacitive sensor (3) in the form of two variable capacitors (4, 5), the capacitance of which is dependent upon the angle and which operate with an angular offset, both capacitors (4, 5) having capacitance values (38, 40) that increase and decrease periodically with the rotational angle; for evaluation, pulses are formed for an additively and subtractively operating electronic counter (16) by continuous comparison of the capacitance values (38, 40) of the two variable capacitors (4, 5) with the capacitance value (39) of a fixed reference capacitor (6), taking into account the direction of rotation which can be derived from the angular offset.