Showing papers on "Electrode array published in 1977"

A multiple-electrode hearing prosthesis for cochlear implantation in deaf patients

Abstract: A multiple-electrode hearing prosthesis for cochlea implantation in deaf patients has been developed at the University of Melbourne. It has been designed as a multiple-electrode implant to provide the best chance of enabling patients to understand speech. It has been shown that an electrode array can be threaded along the coills of the inner ear close to residual auditory nerves. Experimental studies have indicated that the long-term implantation of the array will not lead to significant degeneration of auditory nerve fibres. Loss of platinum from the stimulating electrodes can be minimized with a biphasic constant current pulse, where the first phase is negative with respect to ground. The receiver-stimulator component has also been designed to provide 10-15 channels of stimulation. Furthermore, the phase and amplitude of the stimuli to individual electrodes can be varied to enable the localization of the electrical fields to discrete groups of nerve fibres, and the correct method of frequency and intensity coding to be determined. Finally, the device should be used in the first instance for a specially selected group of adults who are post-lingually deaf.

Analysis and microelectronic design of tubular electrode arrays intended for chronic, multiple single-unit recording from captured nerve fibres.

Abstract: The paper discusses proposals for recording multiple single-unit potentials from nerve fibres that become captured in an array of tube electrodes. Capturing may be through regeneration of cut fibres or by placement of dissected filaments into grooves which are then covered. The factors contributing to signal-to-noise ratios obtainable with this type of electrode are discussed. The design, construction and bench-test results are given for an electrode array in which thin-film microelectronic techniques are used to build a densely packed, flexible, 3-dimensional electrode array consisting of a bundle of plastic tubes with flat metal contacts at midtube.

Method for evaluating a system for electrodeposition of metals

Abstract: A method is provided for evaluating an unknown electrolytic system comprising an electrolytic solution and electrodes for electrodeposition of metal with respect to determining the performance characteristics of the electrolytic solution, detection of impurities and additives in the electrolytic solution, estimation of the current efficiency characteristics of the system, or determining the performance characteristics of an electrode. An electrolytic circuit is established comprising a sample of the electrolytic solution for the system, two electrodes immersed in the solution and spaced from one another therein, and a variable and reversible voltage source having its output terminals respectively connected to the electrodes. A predetermined initial voltage is applied to one of the electrodes constituting a working electrode. Thereafter, the voltage is varied in the negative direction until a predetermined cathodic current or predetermined maximum voltage sufficient to cause a cathodic reaction is attained at the working electrode. The direction of the voltage change is then reversed and the voltage is varied in the positive direction until a predetermined minimum voltage or a predetermined minimum current is attained at the working electrode. This process is repeated through a plurality of cycles and the current obtained is recorded as a function of voltage for a selected cycle. The performance characteristics of the sample solution, the presence of an impurity or additive, the current efficiency, or the working electrode characteristics are determined according to the recorded relationship between current and voltage. This method is useful in the control of electrodeposition processes since it not only provides a basis for evaluating electrolytic solutions and electrodes but further constitutes an analytical tool adapted for determining compositional adjustments necessary for optimum cell performance.

Voltage-current-power meter for photovoltaic solar arrays

Abstract: A meter is disclosed for measuring the voltage, current, and power (VIP) parameters of a photovoltaic solar array, or array module, under sunlight operating conditions utilizing a variable load connected across the array and controlled by a voltage regulator which responds to the difference between the output voltage of the array and a programmed test voltage from a source which generates a single ramp voltage for measuring and recording current as a function of voltage, repeated ramp voltages at a high rate for peak output measurements or a DC voltage for VIP measurements at selected points on the I-V characteristic curve of the array. The voltage signal from a current sensing element, such as a shunt resistor in series with the variable load, is compared with the output current of a reference solar cell to provide a normalizing signal to be added to the signal from the current-sensing element in order to provide a record of array current as a function of array voltage, i.e., for all load conditions from short circuit to open circuit. As the normalized current is thus measured, an analog multiplier multiplies the array voltage and normalized current to provide a measurement of power. Switches are provided to selectively connect the power, P, current, I, or voltage, V, to a meter, directly or through a peak detector. At the same time any one of the parameters V, I and P may be recorded as a function of any other parameter.

Slow rise time write pulse for gas discharge device

Abstract: A gas discharge device having at least one dielectric charge storage member the gaseous medium contacting surface of which consists of a low operating voltage material. The material is used in an amount sufficient to increase the operating life span of the device and/or stabilize the operating voltages of the device. An interface and addressing means is connected to a pair of opposed electrode arrays to energize a plurality of discharge cells, each cell including proximate electrode portions of at least one electrode in each opposed array, said dielectric charge storage member insulating at least one of said proximate electrode portions from said gas. A cell presents a capacitive impedance to a voltage pulse applied by the interface and addressing means to the electrode portions to generate a relatively slow rise time leading edge on the voltage pulse for improved addressing of the cell when the electrode arrays are serially addressed. If at least a portion of the electrodes in one of the arrays are connected for parallel addressing, a keyer pulser connected to these electrodes is turned on to generate a relatively fast rise time leading edge portion on the voltage pulse followed by a relatively slow rise time portion during which the cell is written.

PTC heating device having selectively variable temperature levels

Abstract: A controllable electric heating device uses a PTC resistance body having first areal electrode on one surface and two spaced apart areal electrodes of different areal size on the opposite surface in overlapping relation with a part of the first electrode to provide at least two current paths through the resistance body between the opposite surfaces. The first electrode is connected to one terminal of a voltage source. A switching device selectively connects one or more of the two spaced apart electrodes to the other terminal of the voltage source so that the effective electrode areas are altered thereby adjusting the current flow in the PTC body to produce different temperature levels of the heating device.

Four electrode conductivity sensor

Abstract: In a four electrode conductivity sensor, each pair of electrodes is coupled to a respective one of two operational amplifier circuits that establish a fixed potential relationship between the two potential electrodes so that current flow between the two current electrodes is maintained directly proportional to the conductivity of the solution. Specifically a direct or alternating excitation voltage is applied to the positive input of one operational amplifier, while the other receives a fixed reference potential input. The operational amplifiers supply a unity gain, noninverted output to the respective current carrying electrodes, while the potential electrodes are directly connected to the feedback input of the respective amplifier. The current flow between the current electrodes is measured as a voltage signal across a resistor with the operational amplifier output and remains directly proportional to the conductivity of the solution in which the electrodes are immersed, regardless of fouling of the electrodes by solution impurities and electrolysis effects. An alternating current excitation input can be applied through a coupling capacitor with each electrode also connected through a coupling capacitor to provide direct current that eliminates ground loop problems in the installation and use of metering and control equipment.

Combination measuring and reference potential electrode and method of measuring ph in samples subject to large voltage gradients

Abstract: A combination measuring and reference electrode which has a large annular reference junction around the centrally located measuring electrode filled with a gel electrolyte so as to provide an equal resistivity at the junction in all radial sectors to prevent a net voltage difference between the measuring and reference electrodes due to voltage gradients in the sample.

Apparatus for electrochemical gas detection and measurement

Abstract: Method for the electrochemical detection of a gas and apparatus including a gas-contacting electrode, biased to a predetermined potential, a counter electrode and electrolyte between the electrodes. The electrochemical reaction between the sensed gas and the sensing electrode produces an electric current in a sensing circuit between the sensing electrode and the counter electrode. The sensitivity and stability of the device are maintained by including a conductive member in spaced relationship to the sensing electrode. In accordance with the method, the conductive member is biased to the same potential as the sensing electrode and is selected to have the same response to factors affecting the zero current as the sensing electrode. The conductive member is electrically connected to the sensing electrode so that their zero current outputs are continuously balanced.

Well logging apparatus with pad-mounted vertical electrode array for measuring the resistivity of the flushed zone

Abstract: In accordance with an illustrative embodiment of the present invention, a well logging apparatus uses a narrow wall-engaging pad equipped with an array of long vertical electrodes. The width of the pad is between 2 and 4 inches, and the length-to-width ratio of the array is between 3 and 5. Circuits are connected to the electrodes for propagating a focused current primarily through the zone of the adjacent formation likely to be flushed by the borehole fluid. This current and the associated potential difference are measured to produce a signal representative of the resistivity of the flushed zone.

Electro-optic modulator/deflector

Abstract: An electro-optical modulator/deflector including electro-optical material and an electrode pattern arranged in response to a voltage supply to provide an electric field in the material to influence the deflection of a light beam at the moment of total internal reflection, and at least one further electrode arranged such that on application of a high voltage between said further electrode or electrodes and said electrode pattern there is in use generated within said electro-optical material in the region of said electrode pattern a phase change in the wavefront of the light beam in a sense opposite to the phase change caused by an inherent diffraction grating effect of the electrode pattern.

Acoustic surface wave interaction device

Abstract: An acoustic surface wave interaction device includes a plate of dielectric material provided with two transducers each having at least one pair of comb-shaped electrode arrays having a plurality of teeth. The teeth in one comb-shaped electrode array of each pair are interleaved with the teeth of the other comb-shaped electrode array. At least one transducer has the pair of comb-shaped electrode arrays divided into two or more pairs of comb-shaped electrode arrays which are electrically connected in series, while the length of teeth is varied so that the tip ends thereof are enveloped by a curve representing the inverse Fourier transform of the transfer function of the device. The number of pairs of interleaving teeth to be included in one divided pair of electrode arrays is determined by the length of interleaving of the teeth in order to provide each divided pair of electrode arrays with the same impedance.

Plasma gas phase processor

Abstract: PURPOSE:To uniform the production of CVD film and plasma etching, by splitting one electrode opposing to the test piece into a plurality and by adjusting the distance with the test piece from each electrode with removalbe constitution. CONSTITUTION:Opposed to the semoconductor wafers 3, 4, 5 placed on one electrode 1, the movable electrodes 7, 8, 9, 10, 11 split into a plurality are placed by making different the distance slightly from the electrode 1. Reaction gas is introduced between the opposing electrodes and the distance is set so that the strength of the plasma caused when high frequency voltage is applied among the electrode 1 and the electrodes 7 to 11 can be uniformed over for any location of the electrode as shown in dotted lines 6. Thus, as the reaction of the plasma gas advances, the producing film of the same thickess almost can be deposited on the wafers 3 to 5.

Method and apparatus for open drain addressing of a gas discharge display/memory panel

Abstract: A method and apparatus for operating a gas discharge display/memory panel having a pair of opposed electrode arrays. A pulsating potential sustainer wave form is applied to one electrode array while the other electrode array is maintained at the reference potential of the sustainer wave form, typically the system ground potential. The potentials are applied to the electrodes through switching circuits individual to the electrodes, each circuit including a normally turned on MOSFET and a feed through diode. The MOSFET and the diode are oppositely poled and connected in parallel between the potential sources and the associated electrode. When a cell is addressed, either written or erased, the MOSFETs in the switching circuits connected to the one electrode array are turned off except for the MOSFET connected to the electrode of the selected cell and the MOSFET in the switching circuit for the other electrode array connected to the electrode of the selected cell is turned off while an address pulser for each electrode array is turned on to apply partial select address voltage pulses to the selected cell. During this addressing, the electrodes of the one electrode array are clamped at a predetermined potential and the selected electrode of the other array can have a keyer pulse voltage applied thereto to improve the addressing of the cell.

Ionization promoting electrode and method for increasing ionization efficiency

Abstract: An electrode which has at least one internal channel and an adjustable gate or slot to permit passage of gaseous material to be ionized from the internal channel and then in proximity to one or more outside faces of the electrode in a suitable area of electron emission, the electrode being placed in an electrical field in convenient proximity to an electrode or body of opposite charge.

Focusing ion accelerator

Abstract: A high current ion beam is extracted from an ion plasma by a low perveance ion optical system including a screen electrode, a final electrode and an intermediate electrode therebetween which is shaped to correspond to the extraction voltage equipotentials therebetween. By controlling the voltage of the intermediate electrode with respect to the other two electrodes focusing is accomplished.

Electronic imaging apparatus using multicolor electrophotosensitive particles

Abstract: Electronically controlled imaging with a multicolor mixture of photoconductive particles is effected in a single exposure cycle by provision of an addressable electrode array which is energized selectively in imagewise timed relation. The control device for the imaging system has a plurality of sensing elements for measuring the color density values of successive lines of an original to be reproduced and producing a signal in response to the density measurement to regulate the length of time that the electrode array is energized.

Meter for the flow rate or the speed of a gas stream

Abstract: There is described a meter for the flow rate or the speed of a gas stream, by converting an electric potential metering, which comprises a pair of so-called outer tubular electrodes connected to an electric voltage source and through which the gas stream will pass, said electrode pair forming with a common electrode two series-connected electric fields, as well as an ion source which is located inside the one electrode while the common electrode is connected to a measuring circuit responsive to the potential of said electrode, in which both outer electrodes are arranged on either side and with a spacing relative to the common electrode which is also a tube-like shape.

Field effect pentode transistor

Abstract: A field effect pentode transistor, which provides a gain over an extremely broad band of frequencies is disclosed. The transistor has source and drain electrodes defined by ohmic contacts, a first gate input control electrode defined by a Schottky-barrier, a screen electrode, and a second control gate Schottky-barrier electrode. The screen electrode is an ohmic contact located between the first and second gate control electrodes; and the second control electrode is located between the screen electrode and the drain electrode.

Voltage measurement with spaced reference electrode

Abstract: Method and device for accurately measuring polarization voltage of a measured electrode with a reference electrode in the form of an electrode in direct contact with the ionic conductor and separated in spacing from said measured electrode. The error of ionic conductor IR drop between measured and reference electrodes is corrected by a voltage of opposed polarity connected in series with said reference electrode, made proportional to the DC current polarizing said measured electrode, and adjusted in value to produce a characteristic 0.020 volt separation between transition points of line slope change in the measured initial range of the polarization current-potential relationship. Calibrating circuitry enables an X-Y recorder to accurately plot the current potential relationship.

Charging electrode array

Abstract: A charge electrode array for use in an ink jet printing apparatus is formed by anisotropic etching of apertures through a single crystal silicon substrate of (110) orientation. Conductive diffusion layers in the walls of and adjacent to the apertures permit a charge to be placed on a jet stream passing through the apertures. Contacts can be formed on the adjacent diffusion layers to provide connection to an externally located charging circuit or the contacts may be omitted when the charging circuit is formed in the substrate itself and connected by diffusion or a metal layer to each adjacent diffusion layer. Jet nozzles and synchronization electrodes are shown incorporated in the charge electrode array to form a monolithic structure capable of performing a plurality of functions. Substrate contacts are also provided for biasing.

Developing electrode arrangement for electrophotographic apparatus

Abstract: A photoconductive drum or sheet is movable relative to a developing electrode which is biased to a voltage which prevents smearing of the background areas of the copy. A sensing electrode is disposed upstream of the developing electrode in the direction of movement of the drum or sheet which senses the voltage on the drum or sheet. The sensing electrode is provided in a plurality of independent segments, and a computing circuit selects the voltage on the segment which is lowest in magnitude and which corresponds to a background area of the copy and applies the biasing voltage to the developing electrode in dependence on the sensed voltage. An auxiliary electrode is provided so that the combination of the sensing electrode and the auxiliary electrode is coextensive with the drum or sheet in a direction perpendicular to the movement thereof to prevent streaking of the copy. The auxiliary electrode is either electrically floated and thereby self-biased by the drum or sheet or the biasing voltage from the computing circuit is applied thereto.

Problems in Standardization of Implantable Stimulation Electrodes

Abstract: The emphasis for standardization of implantable stimulating electrodes should be on performance. Among the functional characteristics of the stimulating electrode, only the physical properties may be amenable to some immediate performance standardization. Electrical properties of the stimulating electrode relating to safety may be defined in terms of performance standards in the near future, while those relating to efficacy may evolve later. Standardization of impedance or other electrical design characteristics should not be considered apart from their direct, verified relationship to safety and efficacy of the implant.

Effects of lead wire position along resistive electrode on current distribution in Faraday-type MHD duct.

Abstract: Effects of the lead wire position along the resistive electrodes on the current distribution in a segmented Faraday-type MHD duct when the resistivity of electrodes is larger than the optimal one are investigated. Detailed two-dimensional calculations for current distributions for flat-shaped resistive electrodes indicate that the highly resistive flat electrode with a lead wire placed away from one end can give a substantially uniform current distribution and reduce the Hall electric field at the electrode-insulator interfaces. Also it is shown that the internal resistance due to resistive electrodes for relatively large Hall parameters may be still comparable with the internal resistance for conductive electrodes when the lead wire is shifted to the appropriate position on the resistive electrode.

Gas discharge panel drive system

Abstract: OF THE DISCLOSURE A drive system for an AC driven type gas discharge panel in which either one of the electrode pitches of X and Y electrodes is made smaller than the other and a positive pulse voltage is applied to the electrodes of the smaller electrode pitch and a negative pulse voltage is applied to the electrodes of the larger electrode pitch, thereby to write information in a selected discharge point. The AC driven type gas discharge panel using an electrode arrangement with an asymmetrical electrode pitch has with a max-imum write margin which does not cause half select miss fire.