Showing papers on "Current divider published in 2018"

An Enhanced Frequency-Ratio Coupled-Line Dual-Frequency Wilkinson Power Divider

Abstract: This brief presents a novel design of a dual-band equal split Wilkinson power divider. It is based around a single coupled line section as core and uses stub-based port matching networks at each of the ports. It then incorporates only one isolation resistor, which is independent of frequency-ratio, for achieving perfect isolation. Closed form design equations are developed for the general analysis of the power divider and design case studies are provided to evaluate the proposed design. The developed prototypes for frequency-ratios of 2 and 7 show a good agreement between the electromagnetic simulated and measured results and thus validate the reported theory.

On the design of highly linear CMOS digitally programmable operational transconductance amplifiers for low and high-frequency applications

Abstract: This paper proposes a novel highly linear digitally programmable fully differential operational transconductance amplifier (DPOTA) circuit. Two versions of the proposed DPOTA structure are designed. The first version is optimized for high-frequency operation with current division networks designated to 3-bit control code words. On the other hand, the second version is optimized for low-frequency operation with 4-bit control code words. The third-order harmonic distortion (HD3) of the first DPOTA version remains below − 66 dB up to 0.4 V differential input voltage at 10 MHz frequency. The second DPOTA version achieved HD3 of − 70 dB with an amplitude of 20 mVp–p and at 100 Hz frequency. The proposed circuits are designed and simulated in 90 nm CMOS model, BSIM4 (level 54) under a balanced 1.2 V supply voltage.

Low-Power High-Speed Analog Multiplier/Divider Based on a New Current Squarer Circuit

Abstract: In this paper, a CMOS ultra-low-power, high-speed four-quadrant current multiplier/divider circuit is presented. Based on square-difference approach, the proposed circuit is using a new current squarer with MOS transistors operating in weak inversion region. The translinear loops are the basic building blocks in realization of the current-mode two-quadrant squarer and four-quadrant multiplier/divider circuits. The proposed designs have been simulated using HSPICE in 0.18 $$\upmu \hbox {m}$$ TSMC CMOS (level-49 parameter) process. Post-layout simulation results with 0.8 V power supply show the total power dissipation of 770 nW, the total harmonic distortion of 0.67% (at 100 kHz), the maximum linearity error of 2%, and the − 3 dB bandwidth of 34.1 MHz. Monte Carlo analysis is also performed to ensure the stability and robustness of the circuit’s performance in the presence of the PVT (process, voltage, and temperature) variations.

Design and Analysis of W-Band Injection-Locked Frequency Divider Using Split Transformer-Coupled Oscillator Technique

Abstract: A W-band injection-locked frequency divider (ILFD) with low-power and wide locking range is presented in this paper. The operation frequency and locking range are enhanced by using split transformer-coupled oscillator. The optimum bias and the size of the injection transistor are chosen to achieve wider locking range without increasing chip area and dc power consumption. The proposed ILFD is implemented in 90-nm CMOS and exhibits 25.4% locking range from 75.1 to 99 GHz at an input power of 0 dBm without any tuning mechanism. The core dc power consumption is 2.45 mW with a supply voltage of 0.7 V and the core chip size is $0.13 \times 0.2$ mm2.

Boost–flyback converter with interleaved input current and output voltage series connection

Abstract: This study proposed a high-gain dc-dc converter with an interleaved current at the input stage and voltage series connection at the output stage. This converter was designed based on the boost-flyback topology, which has as main characteristic high voltage gain. Normally, the boost-flyback is designed with the low input voltage, and therefore, the current at this stage reaches high current values, limiting the converter design. Therefore, paralleling the input connection allows the current division between the semiconductors, reducing the switching stress. As part of the converter analysis, in this study, the static and the dynamic converter model are obtained to further design the converter controllers. Furthermore, simulations and experimental results for the proposed converter, operating in closed-looping control, were designed for a peak power of 1.2 kW, reaching a maximum efficiency of 97.5%.

10 – DC-DC Converters

Abstract: Modern electronic systems require high-quality, small, lightweight, reliable, and efficient power supplies. Linear power regulators, whose principle of operation is based on a voltage or current divider, are inefficient. They are limited to output voltages smaller than the input voltage. Also, their power density is low because they require low-frequency (50 or 60 Hz) line transformers and filters. Linear regulators can, however, provide a very high-quality output voltage. Their main area of application is at low power levels as low-dropout voltage (LDO) regulators. Electronic devices in linear regulators operate in their active (linear) modes. At higher power levels, switching regulators are used. Switching regulators use power electronic semiconductor switches in on and off states. Since there is a small power loss in those states (low voltage across a switch in the on state, zero current through a switch in the off state), switching regulators can achieve high energy conversion efficiencies. Modern power electronic switches can operate at high frequencies. The higher the operating frequency, the smaller and lighter the transformers, filter inductors, and capacitors. In addition, dynamic characteristics of converters improve with increasing operating frequencies. The bandwidth of a control loop is usually determined by the corner frequency of the output filter. Therefore, high operating frequencies allow for achieving a faster dynamic response to rapid changes in the load current and/or the input voltage.

High accuracy optical voltage transformer with digital output based on coaxial capacitor voltage divider

Abstract: The voltage transformer based on capacitor divider is susceptible to stray capacitance and Bi4Ge3O12 crystal is sensitive to temperature, which leads to the decrease of measurement precision. To so...

Voltage-Free Distance Protection Method for Closed Loop Structures

Abstract: The conventional method of distance protection relays measures an impedance. Based on conductor voltages and currents, it determines the distance between relay and fault location and enables selective fault clearing. Smart grid environments with closed loop structures increase the capability of connecting distributed energy resources (DER) as inter infeeds. This can cause conventional distance protection malfunctions. This paper proposes a voltage-free distance protection method which complies with closed loop structures and inter infeeds properly. The proposed approach uses the current divider rule and line impedances of the closed loop structure. It is based on negative-sequence currents measured at the relay location. Thus it remains unaffected from negative-sequence current suppressing converter-connected DER and fault resistances. The approach is applied in combination with conventional distance protection which comes into action for symmetrical faults and if the closed loop structure is dissolved. Finally, a protection grading strategy for the proposed approach is presented.

A Novel Direct Power Flow for Distribution Systems with Voltage-Controlled Buses

Abstract: Large-scale distribution systems (DSs) require an efficient power flow algorithm which can explicitly exploit their characteristics. This paper presents a novel power flow algorithm for radial and weakly meshed distribution systems (WMDSs) using a direct method (DM). The paper also develops a novel approach to simulate the voltage-controlled buses which is becoming increasingly important due to the introduction of distributed generations in DSs. The proposed power flow algorithm is constructed based on simple electrical circuit rules so that only a Z matrix expressing common impedances between loads is required for simulation. For WMDSs, only modification is to use the current divider rule to solve meshes. The simulation of PV-buses is presented using the Newton–Raphson solution algorithm. The validation and comparison of results in different systems show the simplicity and low computations of the proposed method which make it time-saving and very efficient for large-scale DSs.

Alternative structures of a segmented current-steering DAC

Abstract: Digital-to-analog converters are widely used in consumer electronics for a message or control signal generation. Two structures of a segmented current-steering DAC are proposed. Both structures improve monotonicity in comparison with the typical segmented DAC structure. The first one is based on a current divider that is connected to an output. The second one is based on a variable bias voltage. Both structures allow to guarantee monotonicity and simplify matching process.

Brushless excitation generator measurement device and measurement method thereof

Abstract: The invention belongs to the field of motor measurement, and in particular relates to a brushless excitation generator measurement device and a measurement method thereof. A brushless excitation generator comprises an oscilloscope, a current divider and a slip ring; the slip ring is connected to first, second and third conductor wires; the slip ring connected to the first, second and third conductor wires is separately matched with first, second and third carbon brushes; the other ends of the first, second and third carbon brushes are separately connected to fourth, fifth and sixth conductor wires; the fifth conductor wire is divided into two branches; the fourth conductor wire and one branch of the fifth conductor wire are connected to two ends of the current divider; the current detection end of the oscilloscope is connected to two ends of the current divider; and the voltage detection end of the oscilloscope is connected to the sixth conductor wire and the other branch of the fifthconductor wire. According to the brushless excitation generator measurement device and the measurement method thereof in the invention, rotating voltage and current signals are transferred into forbidden, steady and measurable voltage and current signals; and, when temperature rise of each winding of the brushless excitation generator is carried out, amplitude and waveform measurement on the rotorexcitation winding of a main generator can be carried out.

Current Divider Based Impedance Comparator

Abstract: The paper describes an ac impedance measurement comparator system which uses a current divider (or splitter). The divider makes use of a current comparator whose windings are connected in a way such as to allow the splitting of a single current signal in two components with very accurate ratio to be attained. Each current component flows through impedances to be compared. Preliminary investigations indicate that such an arrangement is able to provide very accurate impedance measurements with errors of parts in $\pmb{10^{6}}$ or even smaller. Resolutions of parts in $\pmb{10^{9}}$ were also experimentally achieved. Since the system uses a single ac current source, inherent current instabilities of the source cause negligible effects on differential voltage measurements, what alleviates requirements on the ac source. Digital sampling can easily be implemented with the system for speeded-up and automated impedance comparisons.

Third-Order Elliptic Lowpass Filter for Multi-Standard Baseband Chain Using Highly Linear Digitally Programmable OTA

Abstract: In this paper, a third-order elliptic lowpass filter is designed using highly linear digital programmable balanced OTA. The filter exhibits a cutoff frequency tuning range from 2.2 MHz to 7.1 MHz, thus, it covers W-CDMA, UMTS, and DVB-H standards. The programmability concept in the filter is achieved by using digitally programmable operational transconductors amplifier (DPOTA). The DPOTA employs three linearization techniques which are the source degeneration, double differential pair and the adaptive biasing. Two current division networks (CDNs) are used to control the value of the transconductance. For the DPOTA, the third-order harmonic distortion (HD3) remains below -65 dB up to 0.4 V differential input voltage at 1.2 V supply voltage. The DPOTA and the filter are designed and simulated in 90 nm CMOS technology with LTspice simulator.

Repetition frequency pulse capacitor service life testing platform and testing method thereof

Abstract: The invention provides a repetition frequency pulse capacitor service life testing platform and a testing method thereof. In testing the capacitor through a current meter, a voltage meter and a universal meter, a relatively measurement error occurs and furthermore the three methods are performed in a low-voltage state, and the capacitor with a soft breakdown fault cannot be tested. The testing platform comprises a charger (1), a discharging back voltage protection unit (2), a discharging loop (3) and a control unit (4). The charger, the discharging back voltage protection unit and the discharging loop are successively connected in series for forming a service life testing main loop. The discharging back voltage protection unit is a T-shaped protection loop which is composed of two currentlimiting resistors (12) and an anti-parallel diode (14). A resistor voltage divider (20) is paralllelly connected with two ends of a testing capacitor (15) of the discharging loop. The resistor voltage divider and the current divider (16) of the discharging loop are electrically connected with the photoelectric isolating module (11) of the control unit. The invention is used for the repetition frequency pulse capacitor service life testing platform and the testing method thereof.

Current Comparator Based Current Divider

Abstract: The paper describes a current divider (or splitter), i.e., a device that allows the splitting of an alternating current (ac) in two parts in a precise and accurate current ratio. It is based on current comparator techniques so that precise current ratios can be attained with ratio errors bearing parts in $\pmb{10^{6}}$ to $\pmb{10^{9}}$ . A binary current divider can be made virtually exact (i.e., with unitary current ratio errors of the order of some $\pmb{10^{-9}}$ only), if aided by electronic flux error compensation. Further, coupled transmission lines modeling can assess its current ratio errors over frequency. A current divider finds application in many areas of ac metrology as in highly accurate impedance bridges and current measurements.

Integrated device for measuring surface runoff flow and collecting runoff liquid step by step

Abstract: The invention discloses an integrated device for measuring surface runoff flow and collecting runoff liquid step by step. The device comprises an integrated box, an integrated box body, the integratedbox body is internally provided with a deceleration regulator, a current divider box and a runoff collection box, and each collection box corresponds to a current divider box, each current divider box comprises at least two outlets, part of the outlet at the lower side of the current divider box is connected with the inlet of the corresponding runoff collection box, part of the outlet at the lower side of the current divider box is connected with the drain pipe, and the remaining part of outlet of the current divider box is connected with the inlet of the corresponding runoff collection box.the remaining part of outlet of the current divider box is connected with the inlet of the sub-level of the current divider box, the inlet of the deceleration regulator is connected with the inlet ofthe flow diversion pipe, the outlet of the deceleration regulator is connected with the inlet of the current divider box on the uppermost side, and the outlet of the runoff collection box is connectedwith a drain pipe through a drain valve. The integrated device for measuring surface runoff flow and collecting runoff liquid step by step has the advantages of small occupation area low constructionand small engineering; easy collection and cleaning of runoff water, no leakage, easy maintenance and low maintenance cost, and long service life.

Fork shunting device is irrigated to ditch

Abstract: The utility model discloses a fork shunting device is irrigated to ditch, including current divider box, a pair of flow distribution plate and ditch, current divider box inside has two branch roads, the flow distribution plate moves about the cartridge respectively on two ways, the last driving box that is equipped with of current divider box, be equipped with the drive structure in the driving box, the drive structure, it includes: a pair of flexible motor and a pair of link, a pair of flexible motor is settled on driving box, a pair of flexible motor is connected with a pair of flow distribution plate respectively through a pair of link, current divider box inlays and adorns in current divider box every branch road facing wall face has all been offered and has been used for the gliding spout of flow distribution plate, current divider box inlays the dress in the ditch, the utility model relates to an irrigate technical field, among this technical scheme, through drive structure and shielding structure, a pair of spacer plate of accessible shelters from rivers to change water flowing direction, need not the manual work and operate

Analysis and Design of a Broadband Frequency Divider Using Modified Active Loads in GaAs HBT

Abstract: A modified divide-by-2 regenerative frequency divider (RFD) is presented in this paper. The effects of modified active loads on the bandwidth of RFD are demonstrated and analyzed in detail by introducing the equivalent circuit using π model. Using the transimpedance amplifier structure with resistive shunt–shunt feedback and shunt-peaked inductor as the active loads of the generative frequency divider, the loop bandwidth and the loop gain can be increased at higher frequencies to extend the bandwidth. Based on the theoretical analysis and design methodology, an RFD with improved active loads is designed and fabricated in 1μm GaAs heterojunction bipolar transistor technology with a total chip area of 0.83mm×0.75mm. The measured phase noise at the divider output is less than −110dBc/Hz with 100kHz offset and is −127.6dBc/Hz with 1MHz offset. The operation frequency range is from 10 to 26GHz. The power consumption of the divider core is 166.44mW, and the frequency bandwidth is 16GHz at a supply voltage of −6V.

Unbalanced Power Division in an Interleaved Bidirectional Buck Converter: Theory, Simulation and Control Strategy

Abstract: This paper proposes a new approach to divide the total power between different legs in an interleaved bidirectional buck converter, based on the Fibonacci sequence. The paper revises the theoretical analysis of the interleaved buck converter, showing the current ripple analysis; a small signal analysis to find the plants, which represent the circuit, to further derive the control strategy; the validation of these plants via simulation; and the control strategy of the circuit, detailing the unbalanced current division. Finally, simulation results showing that the unbalanced power can be used in an interleaved buck configuration and still achieve zero output current ripple are presented. Discussions among the project adaptations for the interleaved legs, with emphasis for the power semiconductors, are also present in this paper.

Bubbling-type fishing aerator

Abstract: The invention discloses a bubbling-type fishing aerator. The bubbling-type fishing aerator comprises a centrifugal fan, a main floater, a current divider box and an air injection pipe. The centrifugalfan is horizontally installed above the main floater. The current divider box is supported and installed below the main floater. An air outlet of the centrifugal fan is communicated with a current dividing cavity of the current divider box through an air guide pipe. The air injection pipe is a hard straight pipe structure. A plurality of the vertically installed air injection pipes is connected to the lower side of the current divider box, and the upper end of each air injection pipe is communicated with the current dividing cavity. The lower end of each air injection pipe is provided with abubbling port. The bubbling-type fishing aerator is simple in structure. The water beating and spattering effects of a traditional aerator cannot be produced by using a bubbling-type oxygenation mode.The device is quiet and stable in operation, and energy of ascending bubbles is further adequately used, and a floating resistance of the bubbles is further improved, so the bubbles are more lastingunder water, and the oxygen dissolution time is improved.

High Voltage Divider and Resistor Calibrations

Abstract: . . .

A Low-Cost and High-Accuracy Divider Using the Piecewise Linear Method

Abstract: The divider is widely used in the input voltage feedforwad control for dc–dc converters. However, the cost is high. In order to reduce the cost, a linear function of the input voltage is adopted. However, the accuracy is low. Therefore, a low-cost and high-accuracy divider using the piecewise linear method is proposed. The piecewise linear method is illustrated in detail. Only one chip with two operational amplifiers and some passive components are needed, so it is easy to implement and is cheap. Design guidelines and example are provided. Finally, experimental results verify the theoretical analysis. The maximum error is less than 4%, so the accuracy is high.

Low-cost, full-range electronc overload relay device

Abstract: An electronic overload relay leverages a ratio metric current design to permit size and cost optimized circuit components that can be used to sense current for purposes of protecting motors by detecting overcurrent conditions in branch motor applications in lieu of thermal overload devices. A current divider is used to significantly reduce the current that must be sensed by a magnetically coupled toroid to permit its components to be size and cost optimized and to be implemented easily on a printed circuit board. The DC resistance can be used to provide a coarse design that can be calibrated pre-manufacture to establish the accuracy required in sensing motor load current by adjusting the value of the burden resistor. Precision printed circuit board traces can be used to ensure repeatability during manufacturing. A sweepable trigger value generator can permit operation over the entire range of FLC and the threshold can be calibrated into the device.

Low-voltage isolation switch capable of preventing load operation

Abstract: The invention relates to the technical field of an isolation switch, particularly a low-voltage isolation switch capable of preventing a load operation. The low-voltage isolation switch comprises a base; the base comprises a low-voltage isolation switch, a circuit breaker, a voltage reduction transformer and an electromagnetic relay; the voltage reduction transformer and the electromagnetic relaycircuits are also connected with a warning lamp; the low-voltage isolation switch transmits a current to the circuit breaker; and the circuit breaker performs current division to the voltage reductiontransformer, and the reduced voltage is applied to the electromagnetic relay and the two ends of the warning lamp. By virtue of the circuit breaker, the operation of the electromagnetic relay is controlled, and only when the circuit breaker is disconnected firstly, the low-voltage isolation switch can be disconnected, thereby achieving high capability in load operation prevention and simple structure.

Vehicle-mounted battery pack management device self-adapting based on charging curve

Abstract: The invention relates to the technical field of lithium battery packs and specifically relates to a vehicle-mounted battery pack management device self-adapting based on a charging curve. The vehicle-mounted battery pack management device has the advantages of stability in work and high charging efficiency. The vehicle-mounted battery pack management device is characterized in that a controller MCU, a lithium pack assembly and a charging curve replacing circuit are arranged in a shell body; the controller MCU is connected with the lithium battery assembly and the charging curve replacing circuit; the lithium battery assembly comprises a transformer, a rectifying circuit, a current divider, a current sensing circuit, an amplifying circuit, a charging current control circuit, an A/D switching circuit and a D/A switching circuit; the controller MCU is connected with the A/D switching circuit and the D/A switching circuit, the other end of the A/D switching circuit is connected with the output end of the current detection circuit, the input end of the current detection circuit is connected with the output end of the amplifying circuit, and the input end of the amplifying circuit is connected with the output end of the current divider. Compared with the prior art, the vehicle-mounted battery pack management device disclosed by the invention has the obvious advantages of reasonable structure, high work efficiency, low cost and the like.

A New Method to Extend the Current Ranges from 10mA to 100 A at Frequencies up to 100 kHz

Abstract: A new method to extend the current ranges from 10 mA to 100 A at frequencies from 50 Hz to 100 kHz has been described. This method is based on the use of a binary inductive current divider and a set of current transformers to cover the current ranges from lOrnA to 100 A. A $\pmb{1-\Omega}$ shunt of coaxial design has been developed as the time constant standard with known ac-dc difference. The current level dependence of current transformers with ratios of 10:1 and 100:1 and shunts has also been evaluated.

110kV power transmission circuit tower buried lightening current limiting method and device

Abstract: The invention discloses a buried lightening current limiting method and device of a 110kV power transmission circuit tower. A current limiting device is serially connected between a tower and a lightening conductor of a power transmission circuit. The current limiting device comprises a current limiting coil and an iron core. Insulation materials are poured between the current limiting coil and the iron core and to the outer side of the current limiting coil. The upper end outgoing line and the lower end outgoing line of the current limiting coil stretch out of the insulation materials. Inductive effects of the current limiting coil are fully used. On one hand, current division of the lightening conductor is improved, and the amplitude value of the buried current of the thunderbolt tower is reduced. On the other hand, the buried current peak time is increased, the buried current steepness is reduced, the level of the top of the tower can be obviously reduced, and a technical problem issolved that after lightening strikes the 110kV power transmission circuit tower, lightening current passes a tower body of the tower and a grounding body is buried, the level of the tower top will beraised, and when the lightening current amplitude value and the steepness are too big, the level of the tower top will be increased to exceed the voltage resisting level of the insulators, so a fight-back accident is triggered and circuit tripping is caused.

Using the binary inductive current divider to compare two shunt-TVC combinations at common ground

Abstract: The paper describes a new measurement system to compare two shunt-TVC combinations with a testing current ranges of 10 mA to 1 A and frequency ranges up to 200 kHz. This new system is based on the use of Binary Inductive Current Divider (BICD) to provide two currents at common ground, and to eliminate the current leakage influence in series connection mode, especially at high frequency. With this system, ac-ac differences against 1 kHz between two shunt-TVC combinations have been determined, and show well agreement with the method by interchanging shunt-TVC at high and low terminal positions. The measurement results will be presented and the standard measurement uncertainties are below 3 μA/A at frequency ranges from 5 kHz to 200 kHz.