95 results about "Electrical resistance and conductance" patented technology

Systems and methods are disclosed for detecting balanced electrical leakage between a power source and a machine frame. In one embodiment, a balanced fault detection system for a machine includes a power source that is electrically insulated from a machine frame and a leakage detection switch that is connected to a ground. The balanced fault detection system also includes a leakage detection resistor that is interposed between a power source terminal and the switch having a leakage detection resistance. The balanced fault detection system further includes a voltage measuring device that measures voltages of the power source at positive and negative voltage sides of the ground and a leakage calculator that calculates a leakage resistance of the machine based on the measured voltages at the positive and negative voltage sides and the leakage detection resistance.

A heat generating roller, fixing equipment and an image forming apparatus in which warm-up time is shortened while preventing excessive temperature rise and good fixing performance is realized by preventing occurrence of offset. In the heat generating roller, fixing equipment and image forming apparatus, the heat generating roller is formed principally by laying a high permeability conductive layer and a nonmagnetic conductive layer in layer. When a voltage is applied from a power supply (not shown) to an exciting coil and an AC current flow through it, magnetic flux is generated around the exciting coil and a magnetic field is formed. Since the heat generating roller has the high permeability conductive layer and the nonmagnetic conductive layer laid in layer, magnetic coupling of a system consisting of the heat generating roller and the exciting coil is good at the time of low temperature and heat generation of the heat generating roller is accelerated. When the Curie point is exceeded, skin depth becomes deep and skin resistance decreases, which suppresses generation of Joule's heat and reduces heat generation of the heat generating roller.

A temperature regulation system has a polished surface sufficiently smooth so as to reduce the emissivity of the surface. A conduit is in thermal proximity to the polished surface and is in communication with a source of coolant. The coolant is circulated through the conduit so as to transfer heat from the surface to the coolant. System may include a sprayed-on resistive heater. An a temperature controlled vessel has a heat transfer wall that is of an electrically conductive material that is coated with a durable thermally conductive and electrically nonconductive coating. The coating may be a sprayed on coating and the vessel may hold a buffer for performing electrophoresis.

The present invention relates to an apparatus and method for growing a high melting point single crystal having a predetermined orientation, which is grown from a culture rod (3) by a floating zone method or a suspension zone method. The device comprises: culture rods (3) and crystal nuclei (4), a strip-shaped resistance heating type heating strip (6) provided with at least one opening is installed between its ends and next to it, and it is heated To the crystal melting temperature, so as to form the melting zone (5), drive mechanism (8, 11), so that relative movement occurs between the heating belt (6) and the crystal nucleus (4) and the culture rod (3) that are installed next to the heating belt , the molten liquid material of the culture rod (3) is obtained through each opening of the heating belt, and causes single crystal growth on the crystal nucleus (4) by cooling, and another heating device (15, 16), which is arranged at the melting The vicinity of the zone (5) in order to set the temperature gradient within the range of the melting zone (5). In order to reduce the temperature gradient in the melting zone, said further heating device (15, 16) comprises at least one heating coil (17, 19), which is driven with radio frequency, wherein the heating strip (6) and the respective heating coil are thus mounted opposite each other (17, 19) so that radio frequency radiation is coupled on the heating strip in order to generate an additional inductive heat input in the heating strip and to set a temperature gradient across the melting zone (5). This enables an inductive heat input into the heating strip, which can be varied or varied in a targeted manner.

The invention provides a distribution transformer winding material detection system and method. The distribution transformer winding material detection system comprises a heating device, a curve acquisition device, a storage device and a matching device, wherein the heating device is for heating a to-be-detected distribution transformer winding; the curve acquisition device is for acquiring a detection curve, changing with the temperature of the winding, of the direct current resistance of the to-be-detected distribution transformer winding; the storage device is for storing a standard curve, changing with the temperature of the winding, of the direct current resistance of a standard distribution transformer winding made of a known winding material; and the matching device is used for matching the detection curve and the standard curve. According to the provided distribution transformer winding material detection system and method, the accuracy for field detection of the distribution transformer winding material is improved through matching of the temperature-resistance curve of the distribution transformer winding.

An improved heating system air pressure sensing port. An example aircraft pitot tube heater uses Positive Temperature Coefficient (PTC) switching thermistors arranged to automatically sense the outside air temperature and heat to a design set point temperature. When a high outside air temperature is experienced, the pitot tube will not turn on. The pitot tube heater only turns on below the design set point and will consumes less current than the standard aircraft pitot tube heaters when operating at very cold temperatures. Virtually no current is drawn when the pitot tube increases past the set point, thus reducing the power drain on the aircraft system. The use of multiple thermistors gives the example pitot tube a level of failure redundancy that is not available in current pitot tube heaters.

The invention discloses a current generating circuit with an adjustable temperature coefficient. The current generating circuit comprises a current mirror, an operational amplifier, a switching tube,at least two positive temperature coefficient resistors, at least two negative temperature coefficient resistors, a positive temperature coefficient switch and a negative temperature coefficient switch. Thus, on the basis of a voltage-to-current circuit in the prior art, output current is appropriately matched, the current generating circuit achieves the adjustable temperature coefficient, resistance matching is different from traditional pure serial connection or pure parallel connection, and circuit space is saved; the accuracy of the temperature coefficient is high.

The invention provides a welding method aiming at the butt welding of small caliber resistances. The method is applicable to the welding of small caliber steel pipes, wire rods and rings, and also applicable to the contact butt welding of small caliber nonferrous metals such as aluminium and magnesium wire rods and pipe products, belonging to the welding technical field. As stainless steel is slow in heat dissipation, the invention proposes a welding technique with intermittent heating and continuous and uneven heat dissipation. The high temperature plastic zone in the welding temperature field obtained by the process is narrow and can be less affected by the contact resistances; the welding shrinkage can be controlled accurately by the process; the welding line moulding has a beautiful appearance; the strength and the through-hole both meet the requirements, thus greatly improving the qualification rate of products.

A source-drain voltage of one of two transistors connected in series becomes quite small in a set operation (write signal), thus the set operation is performed to the other transistor. In an output operation, two transistors operate as a multi-gate transistor, therefore, a current value can be small in the output operation. In other words, a current can be large in the set operation. Therefore, the set operation can be performed rapidly without being easily influenced by an intersection capacitance and a wiring resistance which are parasitic on a wiring and the like. Further, an influence of variations between adjacent ones can be small as one same transistor is used in the set operation and the output operation.

Disclosed herein is a semiconductor-device manufacturing method including the steps of: computing a capacitance, a resistance as well as capacitance and resistance variations as quantities generated as a result of changing the physical layout of a semiconductor integrated circuit in a range determined in advance; dividing the physical layout of the semiconductor integrated circuit into functional blocks and analyzing the physical layout in the functional-block units; computing signal delays for each of the functional blocks from the computed capacitance, the computed resistance as well as the computed capacitance and resistance variations and from a delay table provided for element and wire sections of each of the functional blocks; and finding signal delays in all the functional blocks composing the semiconductor integrated circuit on the basis of the signal delay computed for each of the functional blocks and the basis of a result of the analysis carried out on the physical layout.

The invention discloses a method for determining reservoir water saturation, which comprises the following steps of: obtaining the porosity and permeability of a rock core, and establishing a porosity-permeability calculation model by combining acoustic logging data; Obtaining a saturation index n value, and establishing a reservoir resistivity calculation model when the water content is 100%; Respectively establishing a calculation model of irreducible water saturation and residual oil saturation; Determining the resistivity of the original formation water and the resistivity of the slurry filtrate of the oil reservoir by utilizing test analysis, and determining the resistivity of a pure oil layer by irreducible water saturation, residual oil saturation, resistivity of a flushing zone anda saturation index; And establishing a new reservoir water saturation calculation model, and calculating the reservoir water saturation through the reservoir measurement resistivity, the reservoir resistivity when the water content is 100%, the pure oil layer resistivity and the irreducible water saturation. According to the method, the water saturation of the reservoir stratum is solved point bypoint through logging data without depending on an alpha formula under the condition that formation water resistivity of different stratum sections of the stratum is unknown, and a new method is provided for accurately solving the water saturation of the reservoir stratum.

The invention discloses a circuit for a low-voltage adjustable band-gap reference source. Collectors and bases of three PNP triodes are grounded; the emitter of the first PNP triode is connected with one end of a first resistor; the other end of the first resistor is connected with the positive input end of an operational amplifier and the drain of a first P-channel metal oxide semiconductor (PMOS) transistor; the emitter of the second PNP triode is connected with the negative input end of the operational amplifier and the drain of a second PMOS transistor; the emitter of the third PNP triode is connected with one end of a second resistor; the other end of the second resistor is connected with the drain of a third PMOS transistor and one end of a third resistor; the other end of the third resistor is grounded; the output end of the operational amplifier is connected with the grids of the three PMOS transistors; and the sources of the three PMOS transistors are connected with a power supply. According to the circuit, configurable reference output voltage can be realized; and the influence of offset voltage of the operational amplifier on a starting circuit is avoided.

The invention belongs to the technical field of electronic devices, and particularly discloses a method for adjusting a resistance value of a negative temperature coefficient (NTC) thermistor chip. The method comprises the following steps of: (1) preparing a thermosensitive semiconductor ceramic powder; (2) molding, sintering and preparing an NTC thermosensitive ceramic chip; (3) coating an upper end electrode; (4) welding a lead wire; (5) aging; (6) adjusting the resistance value; and (7), encapsulating and testing. During the process of the adjustment method, an initial value of the NTC thermistor chip is undersized; the resistance value of the NTC thermistor chip during finely grinding can become large continuously and gradually; by precise control of the grinding quantity, the resistance value of the NTC thermistor chip can be controlled at 0.1 percent; under the condition of the resistance value precision of +/-0.3 percent during batch production, the qualification rate is up to 90 percent, so a precise resistance adjustment process of the NTC thermistor chip can be realized effectively, and the precision of the NTC thermistor chip is high; and the method can be widely applied to various temperature detection circuits, temperature compensation circuits, temperature control circuits and the like.

According to one embodiment, a digital protection relay includes an auxiliary transformer (2) which decreases a voltage of an electrical signal from a main circuit transformer (1) to a predetermined voltage; a detection resistance circuit (20) including a Π-type or T-type circuit including an input connected to an output of the auxiliary transformer (2); an analog detection circuit (3) which is connected to an output of the detection resistance circuit (20) and detects a quantity of electricity of an electrical signal from the auxiliary transformer (2); an A/D conversion circuit (4) connected to the analog detection circuit (3); a central processing device 5 which is connected to the A/D conversion circuit (5) and performs a protection operation; and a trip output contact (9) which is closed by processing of the central processing device (5) and operates an external breaker (21). In the digital protection relay, an input contact terminal 11 for inputting a test signal with a constant voltage from an external test device (13) to the analog detection circuit (3) as a signal corresponding to an output of the auxiliary transformer (2) is provided between the detection resistance circuit (20) and the analog detection circuit (3).

A sensor includes a stretchable substrate having a stretching property, and a plurality of wires provided to the stretchable substrate, and the plurality of wires includes a first wire, and a second wire larger in resistance value variation due to extension of the stretchable substrate than the first wire. Further, the sensor includes a detection section adapted to correct a resistance value of the second wire in accordance with a resistance value of the first wire, and detect the extension of the stretchable substrate based on the resistance value of the second wire which has been corrected. Further, the detection section detects deterioration of the plurality of wires in accordance with the resistance value of the first wire.

The invention discloses a novel transformer station secondary cable alignment device. The device comprises a detected end and a detection end which are respectively arranged at two ends of a to-be-detected secondary cable, and a voltage measurement device used for measuring a voltage of the two ends of the secondary cable, wherein the detected end is provided with a power source, a switch K1, N wiring ends and N+1 wiring resistors connected in series between the power source and the switch, and the N wiring ends are respectively connected with wiring nodes of any two adjacent wiring resistors. The device is advantaged in that through setting alignment terminals, the wiring resistors are arranged among the alignment terminals, all the wiring resistors are connected in series with a certain voltage, a voltage of any two points of each wiring terminal can be determined, so a voltage difference table can be made, through voltage measurement of the other end of the to-be-detected secondary cable, determination of corresponding labels can be carried out through a table query method, cable alignment can be accomplished, the device is integrally convenient and rapid, and low cost and high precision are realized.

Apparatus and method for draining stored power are disclosed, which the apparatus and method are applied to an EMI filter circuit for draining power. When the power supply circuit is not working, the apparatus provides a bleeder resistor to drain the power stored in the capacitors of the EMI filter circuit. On the other hand, when the power supply circuit is working, the apparatus provides an open-circuit resistor which has extremely large electrical resistance in order to stop draining power. Thus, the apparatus for draining stored power will not cause extra power waste.

The invention provides a common mode moving circuit for a multipoint low voltage differential signal receiver. The common mode moving circuit comprises a first resistor, a second resistor and a current regulating circuit as well as an error amplifier, wherein the current regulating circuit is formed by a third and fourth resistors and first to sixth transistors; grids of the second and fifth transistors are in a short connection with a drain electrode; grids of the first, second and third transistors are connected with each other and the source ends are grounded; grids of the fourth, fifth and sixth transistors are connected and the source ends are connected with power supply voltage; drain ends of the first and fourth transistors are connected with the first resistance; the third and fourth resistance is in a serial connection between a drain end of the second transistor and a drain end of the fifth transistor; drain ends of the third and sixth transistors are connected with the second resistor; a difference-mode input end of the error amplifier is connected with a reference level; and a common mode input end is connected with the drain ends of the first and third transistors. No effects are caused to input signal differential value; and the common mode moving circuit has system noise ratio higher than a receiver using a compression network.

The invention discloses a fatigue driving alarm device and alarm method, and belongs to the field of automobile driving alarm. The alarm device comprises a left skin resistance collection module, a left skin temperature collection module, a right skin resistance collection module, a right skin temperature collection module, a left skin resistance constant current source, a left skin temperature constant current source, a right skin resistance constant current source, a right skin temperature constant source, a left skin resistance sampling circuit, a left skin temperature sampling circuit, a right skin resistance sampling circuit, a right skin temperature sampling circuit, a single-chip microcomputer, an alarm module, and a power supply. The device collects the skin resistance and skin temperature signals of the left and right hands, holding a steering wheel, of a driver, converts the skin resistance and skin temperature signals into voltage signals, carries out the averaged statistics of the skin resistance and skin temperature signals in a preset time period, judges the fatigue features of the driver according to the change conditions of statistical values, starts the alarm module, solves problems that a conventional fatigue driving alarm device is not stable and accurate, is strong in anti-interference capability, is accurate in collected data, is accurate in judgment of fatigue features, and is wide in application range.

The invention discloses a method for detecting an inner connecting resistor of a power battery pack. The method includes the following steps that (1) the alternating current inner resistance Zi of each battery cell is tested before battery modules are assembled; (2) the alternating current inner resistance Zm of each battery module is tested after the battery modules are assembled and before the battery pack is assembled, and the inner connecting resistor comprehensive value Rci of each battery module is calculated through the Zi and the Zm; (3) constant-current discharge is conducted on the power battery pack, the direct current resistance Di of each battery module and the direct current resistance Dp of the battery pack are calculated, and the connecting resistor comprehensive value Rco between the modules is calculated through the Di and the Dp; (4) the inner connecting resistor comprehensive value Rc of the battery pack is calculated through the formula Rc=Rci+Rco; (5) the inner connecting resistor of the power battery pack is evaluated through the Rc. According to the method for detecting the inner connecting resistor of the power battery pack, the structure of the battery pack does not need to be damaged, the Rc can be calculated effectively and conveniently, and therefore support is provided for the connecting resistor design of the battery pack and the electrical property and health condition judgment.

The invention discloses a measurement circuit and method for an insulation monitoring instrument fault circuit. The measurement method comprises the steps that firstly, a low-frequency square-wave pulse signal with the positive electrode and the negative electrode symmetrical is generated inside an insulation monitoring instrument; secondly, a measurement loop is formed through high negative voltage, a full ground plane and an insulation resistor Rf-dc; thirdly, a sample voltage is generated on a sampling resistor Rm through current in the measurement loop; fourthly, the sample voltage is sent to a built-in microprocessor for acquisition, and the numerical value of the insulation resistor Rf-dc can be obtained by conducting calculation according to the redundant binary algorithm. The measurement circuit and method for the insulation monitoring instrument fault circuit have the advantages the measurement precision is high, reliability is high, safety is high, and the circuit and method are suitable for different environments.

An anti-static sole is provided with a pad body between a midsole and an insole. In the pad body is provided a chip resistor. The chip resistor includes a connecting pin at each of two opposite ends thereof. The two connecting pins of the chip resistor are electrically connected to the insole and the midsole, respectively. Since the chip resistor has no exposed wires, damage to the wires is avoided. Further, the anti-static effect can be improved since the resistance of the chip resistor is stable.