2578 results about "Varistor" patented technology

Embodiments of the invention include a method of forming a nonvolatile memory device that contains a resistive switching memory element that has improved device switching performance and lifetime, due to the addition of a current limiting component disposed therein. The electrical properties of the current limiting component are configured to lower the current flow through the variable resistance layer during the logic state programming steps by adding a fixed series resistance in the resistive switching memory element of the nonvolatile memory device. In some embodiments, the current limiting component comprises a varistor that is a current limiting material disposed within a resistive switching memory element in a nonvolatile resistive switching memory device. Typically, resistive switching memory elements may be formed as part of a high-capacity nonvolatile memory integrated circuit, which can be used in various electronic devices, such as digital cameras, mobile telephones, handheld computers, and music players.

A display system includes a substrate upon which the display system is fabricated; a printable electrooptic display material, such as a microencapsulated electrophoretic suspension; electrodes (typically based on a transparent, conductive ink) arranged in an intersecting pattern to allow specific elements or regions of the display material to be addressed; insulating layers, as necessary, deposited by printing; and an array of nonlinear elements that facilitate matrix addressing. The nonlinear devices may include printed, particulate Schottky diodes, particulate PN diodes, particulate varistor material, silicon films formed by chemical reduction, or polymer semiconductor films. All elements of the display system may be deposited using a printing process.

The invention comprises use of Dynamically Switchable Bypass (DSB) elements in association with one or more Light Emitting Diodes (LEDs) in arrays for illumination circuits to provide rugged, reliable lighting. The DSBs are selected from Transient Voltage Suppressors, including Silicon, Metal Oxide Varistors, and Multi Layer Varistors as well as Zener Diodes. The DSBs are not used as circuit protecting devices, but rather as alternative paths for electric current to bypass failed LEDs. Bi-directional TVSs are used as alternative electric paths for circuits using Alternating Current (AC) and parallel LED arrays that light on both phases of AC. Zener Diodes are used in parallel to, but in the opposite polarity orientation to, one or more LEDs in DC or rectified AC circuits. The inventive paired DSB / LED elements overcomes the black-out problems of prior series LED illumination systems, making possible the use of robust LEDs in illumination systems where reliability, long life, low power consumption, low heat output, resistance to shock, vibration, and humidity, and self-diagnosis are important. The DSB elements have breakdown voltages slightly higher than the LED(s) they support, so that when an LED fails, the conduction through the DSB begins. Because the conduction voltage of the DSB so nearly matches the conduction voltage of the LED(s), the remainder of the circuit continues to function as normal. The system is self-diagnostic in that any LED failure presents itself as a dark LED rather than as a whole string of dark LEDs. DSBs may be used with incandescent bulbs.

Resistive memory devices having at least one varistor and methods of operating the same are disclosed. The resistive memory device may include at least one bottom electrode line, at least one top electrode line crossing the at least one bottom electrode line, and at least one stack structure disposed at an intersection of the at least one top electrode line and the at least one bottom electrode line including a varistor and a data storage layer.

Methodologies and structures are disclosed for providing multilayer electronic devices having low inductance and high ratings, such as for capacitor devices for uses involving faster pulsing and higher currents. Plural layer devices are constructed for relatively lowered inductance by relatively altering typical orientation of capacitors such that their electrodes are placed into a vertical position relative to an associated circuit board. Optionally, individual leads may be formed so that the resulting structure can be used as an array. Internal electrodes may be arranged for reducing current loops for associated circuits on a circuit board, to correspondingly reduce the associated inductance of the circuit board mounted device. Leads associated with such devices may have added tab-like structures which serve to more precisely place the lead, to improve the lead to capacitor strength, and to promote lower resistance and inductance. Disclosed designs for reducing associated inductance may be practiced in conjunction with various electric devices, including capacitors, resistors, inductors, or varistors.

A laminated-type varistor includes a laminated structure and a pair of external electrodes disposed on a surface of the laminated structure. The laminated structure includes effective sintered body layers and internal electrodes. The internal electrodes are connected to the external electrodes and are disposed apart from each other in the direction perpendicular to lamination surfaces. Each of the internal electrodes has a multilayer electrode structure in which a plurality of electrode layers are arranged in layers while an ineffective sintered body layer is disposed therebetween. The laminated-type varistor has increased maximum peak current and maximum energy and reduction in clamping voltage.

A light emitting apparatus is comprised of a multilayer chip varistor having a varistor element body, a semiconductor light emitting element, and a reflecting portion. The varistor element body includes a varistor layer, and a plurality of internal electrodes opposed to each other so as to interpose the varistor layer between the internal electrodes. The semiconductor light emitting element is disposed on the multilayer chip varistor and is electrically connected to the plurality of internal electrodes so as to be connected in parallel to the multilayer chip varistor. The reflecting portion is disposed between the multilayer chip varistor and the semiconductor light emitting element. The reflecting portion reflects light traveling toward the multilayer chip varistor out of light generated by the semiconductor light emitting element.

A surge protection device is disclosed that includes an input path for receiving an rf signal, dc power, and a surge, an output path for propagating the rf signal, and a dc blocking device coupled in series between the input path and the output path. The surge protection device also includes a first inductor coupled to the input path for isolating the rf signal and providing a path for the dc power, a gas tube coupled to the first inductor for routing a portion of the surge to a ground plane, a second inductor coupled to the first inductor for providing a path for the dc power, and a metal oxide varistor coupled to the second inductor for routing a portion of the surge to the ground plane. Furthermore, the surge protection device includes a third inductor coupled to the second inductor for providing a path for the dc power, a diode coupled to the third inductor for routing a portion of the surge to the ground plane, and a fourth inductor coupled to the third inductor for providing a path for the dc power to the output path.

A transient voltage / surge current protection system is provided for electronic circuits associated with implanted leads. In particular, a transient voltage suppressor such as a diode, a zener diode, a transorb, a surge protector, varistor components or the like, is placed in parallel with the electronic circuits to thereby divert harmful surge current and bypass the electronic circuit during an external defibrillation event or during an applied therapeutic shock, such as from an ICD.

On the surface of a ceramic sinter, at least an external electrode for input, an external electrode for output, and external electrodes for grounding are disposed, and the ceramic sinter includes an inductor electrically connected to the external electrode for input and external electrode for output, and a varistor electrically connected to the external electrode for input and external electrodes for grounding. By connecting the inductor to the signal line of the circuit of an electronic appliance and connecting the varistor between the input side of the signal line and the ground, electrostatic discharge pulses of about 0.5 to 2 nanoseconds can be suppressed efficiently.

A suppression and protection circuit is used in conjunction with a circuit interrupter. In one configuration, a voltage clamping device such as a metal oxide varistor is utilized in a ground fault circuit interrupter product for handling transient surges and overvoltage conditions and is placed in series with a solenoid coil. The suppression and protection circuit includes a crowbar device across the line such as a header spark gap to prevent overvoltages, and a low pass filter such as an LC filter for suppressing transient surges.

A thermal management system for reducing or eliminating heat-mediated degradation of LED performance and / or operating life. The system may include a thermal controller arranged to respond to an LED operating condition, and to responsively limit temperature in the LED. The thermal controller in one implementation includes a bypass circuit containing a bypass control element, such as a varistor, Zener diode, or antifuse device, and arranged to divert current from flowing to the LED so that the LED remains in a cool state, e.g., below 75° C. The system may be arranged to (I) at least partially attenuate the power supplied to an LED so as to reduce heat generation in such LED and maintain the LED below a threshold temperature and / or (II) remove heat from the LED to maintain temperature of the LED below a threshold temperature.

The invention concerns novel varistors based on zinc oxide and a method for making same, which consists in using as base products nanocrystalline powders obtained by high-intensity mechanical grinding and in subjecting the mixture resulting from said nanocrystalline powders a consolidating treatment such as sintering, in suitably selected temperature and time conditions so as to retain the smallest possible grain size of ZnO. The resulting varistors have a very fine homogeneous microstructure and an average grain size characteristically not more than 3pm, i.e. five times smaller than standard materials. Said novel varistors have a larger number of grain boundaries per unit length unit and therefore a much higher breakdown voltage. Said voltage is characteristically higher than 10 kV / cm and can reach 17 kV / cm which is almost one order of magnitude above the breakdown voltage of standard varistors. The non-linearity coefficient of the current-voltage curve is also improved, and is greater than 20 and can reach values as high as 60. Moreover, the leakage currents below the breakdown voltage of said varistors, are much lower.

The invention provides a thermal protection voltage-sensitive resistor module used for surge protection, which consists essentially of a metal oxide voltage-sensitive resistor, a thermal response switch, a set of thruster with a compression spring and a wedge-shaped quencher and a case. Thermal coupling exists between the thermal response switch and the metal oxide voltage-sensitive resistor. When the metal oxide voltage-sensitive resistor is overstressed, the resistor emits heat, the thermal response switch can immediately sense the heat and soften the welding point of solder with low melting point, then the welding point is forced to be quickly disconnected and part of the wedge-shaped quencher is inserted into the clearance at the breakage place of the welding point under the joint effect of the thruster with the spring and the wedge-shaped quencher and the resilient conductive connection arm, thus the quenching effect is enhanced.

A filter circuit in a surge protection device comprises a Y-capacitor, a first metal oxide varistor (MOV) coupled between a first line and the Y-capacitor, and a second metal oxide varistor (MOV) coupled between a second line and the Y-capacitor.

There is a provided a magnetic and dielectric composite electronic device, comprising: a first region with a plurality of magnetic material sheets being layered; a second region with a plurality of dielectric material sheets being layered; and a third region as a middle layer interposed between the first region and the second region, including a Zn—Ti based material to prevent diffusion of the materials during co-firing of the first region and the second region, and the first region, the second region and the third region are integrally formed in a single body. In accordance with the present invention, the low pass filter including the function of the varistor is realized to obtain the EMI function and the ESD control effect. Furthermore, the one chip electronic device having the composite functions is manufactured by a simple process, and the interdiffusion between the different materials forming the magnetic and the dielectric parts is prevented to secure the durability and electrical characteristics of the product.

The present invention provides a memory cell having a variable resistor as a memory element, and also provides a memory device comprising the memory cells. The variable resistor is made of a thin-film material (for example, PCMO) or the like having a perovskite structure. So the memory cell can operate at a low voltage and can be highly integrated. The memory cell MC is formed of a combination of a current controlling device and a variable resistor. A field-effect transistor, diode or bipolar transistor is used as the current controlling device. The current controlling device is connected in series with the current path of the variable resistor so as to control a current flowing through the variable resistor.

A device to protect against a surge voltage includes a body having a hexahedron shape and filled with a varistor material, a pair of input signal electrodes attached to a first side surface of the body along upward and downward directions, a pair of output signal electrodes attached to a second side surface of the body that faces the first side surface of the body in the upward and downward directions, a ground electrode attached to an upper surface of the body, at least one pair of signal connection electrode plates to connect the input signal electrodes and the output signal electrodes, and a ground plate to be connected to the ground electrode. Thus, the device can protect an electronic circuit from a surge voltage and match an impedance of a transmission line.

A light-adjusting and current-limiting control circuit for a lamp includes a sampling circuit formed of a manganese-copper line or a current transformer, a power circuit provided with resistors, capacitors, diodes, a Varistor and a zener diode, a signal adjusting circuit composed of diodes, resistors, a varistor, triacs and capacitors, and a control output circuit having a thyristor, diodes, a relay and an LED. The control output circuit can be replaced with a light-adjusting input circuit, a chip processor control circuit, a zero-crossing detection circuit and a two-way silicon controlled rectifier control output circuit 5. Thus, the invention has a low cost, a small size and an excellent precision, compared to conventional ones.

A device for protection against voltage surges in an electric power supply line includes at least two elements (1′, 3), namely a Zener diode lightning arrester (1′) fast-blow in short circuit, and a varistor (3), arranged in parallel. One of the terminals common to the two elements (1′, 3) is connected to the line to be protected, and the other common terminal is connected to earth or to a common conductor element.

A surge protection device is disclosed that includes an input path for receiving an rf signal, dc power, and a surge, an output path for propagating the rf signal, and a dc blocking device coupled in series between the input path and the output path. The surge protection device also includes a first inductor coupled to the input path for isolating the rf signal and providing a path for the dc power, a gas tube coupled to the first inductor for routing a portion of the surge to a ground plane, a second inductor coupled to the first inductor for providing a path for the dc power, and a metal oxide varistor coupled to the second inductor for routing a portion of the surge to the ground plane. Furthermore, the surge protection device includes a third inductor coupled to the second inductor for providing a path for the dc power, a diode coupled to the third inductor for routing a portion of the surge to the ground plane, and a fourth inductor coupled to the third inductor for providing a path for the dc power to the output path.

So-called quantum tunneling varistors are made with a matrix of particles having a nonconductive coating that is deposited on core conductive particles using atomic layer deposition methods. The resulting coated particles have highly uniform, adherent coatings that allow easier production of good quality quantum tunneling varistor devices.

An overvoltage protection device includes first and second electrically conductive electrode members, a varistor member formed of a varistor material and electrically connected with each of the first and second electrode members, and an electrically conductive, meltable member. The meltable member is responsive to heat in the device to melt and form a current flow path between the first and second electrode members through the meltable member.

Provided is a method of manufacturing a semiconductor device having a switching device capable of preventing a snake current. First, a transition metal oxide layer and a leakage control layer are alternately stacked on a substrate 1 to 20 times to form a varistor layer. The transition metal oxide layer is formed to contain an excessive transition metal compared to its stable state. The leakage control layer may be formed of one selected from the group consisting of a Mg layer, a Ta layer, an Al layer, a Zr layer, a Hf layer, a polysilicon layer, a conductive carbon group layer, and a Nb layer.

A motor drive employs a combination of gas discharge tubes and metal oxide varistors to create precisely tailored surge protection that has a low leakage current minimizing the triggering of ground fault detection circuitry when multiple motor drives are attached to a single line source.

A multilayer varistor comprising a varistor chip body having alternately stacked ceramic layers and internal electrode layers is provided. The ceramic layer is composed of a composite oxide containing Ti and / or Zr and Ba as a main component and Si and / or Al as a subordinate component, substantially free of Cr, and has a perovskite phase. The internal electrode layer is composed of a conductor containing a base metal such as Ni or Ni alloy as a main component. The varistor is used in an electric circuit for suppressing noise.