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A novel and simple structure for improving CMRR is introduced. This structure can be added to the circuits like folded cascode amplifier, telescopic amplifier, current buffers, .etc to improve the CMRR of these circuits. This simple and effective circuit uses common mode deviating technique to improve CMRR at least 12dB while preserves CMRR bandwidth which is a novel technique in order to improve...
A DC-invariant gain control technique is introduced for differential CMOS variable-gain low-noise amplifiers (VG-LNA). Such technique provides an advantage of invariant DC bias current when the RF power gain is tuned over the gain control range. Therefore, the transconductance of NMOS transistor is unchanged, which minimizes the input match detuning. Consequently, the optimal design for noise, gain...
In this paper we propose a variable-gain transimpedance amplifier suitable for low-power applications. Its noise, bandwidth and input impedance performance are similar to a more conventional regulated-cascode common-gate transimpedance with resistive load, with the same power consumption and gain performance. The proposed amplifier has, however, variable gain, which can be easily changed by setting...
A high voltage charge pump design is being presented in this paper. The design is based on Dickson charge pump, constructed with diodes by using AMS 0.35μm technology. The innovation is made in Dickson charge pump i.e. charge control PMOS transistor is used in each stage of charge pump. PMOS transistor is used in series with charging capacitor which reduces the power consumption during the clock transition...
This paper presents a transmitter design for Ultra Wideband Impulse Radio (UWB-IR) communications. The design is targeted towards the implementation of passive Wireless Sensor Tags (WST) where micro-power consumption is required. The transmitter has been implemented in UMC 0.18μm CMOS and placed inside a QFN lead-less package. It complies with the FCC regulations for Pulse Rate Frequencies (PRF) up...
A differential delay cell with complementary current control to extend the control voltage range as well as the operation frequency is proposed for high speed and wide tuning range voltage-controlled ring oscillator (VCRO). The complementary current control mitigates the restriction that control voltage can not operate at full range in a conventional VCRO. A three-stage VCRO is constructed for verifying...
Based on the background of battery charging system, in this paper, the small-signal equivalent circuit model of phase-shifted full-bridge ZVS DC/DC converter is established, then its transfer function is derived, and a single closed-loop voltage-mode controller is designed. In order to analyze anti-grid voltage disturbance capacity, transfer function of audio susceptibility is presented, and the anti-grid...
This paper introduce the technology of electromotor control and protective electrical appliance intelligent, using the artificial fish swarm algorithm (AFSA) which is based on genetic algorithm to optimize the calculate of the intelligent ac contactor. According to the result of optimization design, we have made a showpiece, after the test and experimentation of the prototype; finally we got results...
An ac voltage regulating system of doubly Salient Electro-magnetic Generator has been performed in this paper. In order to maintain the high voltage 360VDC stable, the dual boost converter with fixed frequency PWM controlled is adopted. Three-phase dual buck inverter was adopted to output 115VAC/400Hz. the generating system configuration, control strategy of dual boost converter and three-phase dual...
In embedded systems design, low power design must be the problems faced. From this, mainly from the CPU CMOS circuit design, low consumption of dynamic power management from three aspects, low-power embedded system design, is analyzed.
This paper analyzes Henan power circuit breakers with closing resistors operation. Selecting a typical substation as the research object, switching overvoltage and surge arrester energy absorption were simulated without the closing resistor. Measured through the field test verified the accuracy of the simulation. The relations between line length and over-voltage level was also analyzed. The result...
Most of the current sensorless control schemes for BLDC (Brushless DC) motor are based on full-bridge driver. However, half-bridge driver draws a lot of attention due to its simpler structure, smaller occupied volume, lower power loss, easier control scheme and lower production cost, and it has been successfully utilized in several applications. Inspired by these applications, this paper presents...
Microgrid has lots of advantages and effective methods in usage and control of DGs, and has developed rapidly at each country. Electric Vehicles regarded as new traffic method has been paid more common attention. Batteries of electric vehicles can be regarded as mobile power storage devices, which will affect the stability of the power grid when paralleled in the grid. A common structure of the microgrid...
The main purpose of this paper is to design a pulse-width-modulated (PWM) pulse power supply to test the performance of the solenoid valve. In order to achieve this purpose, from hardwave stage, one of the main part of designing is to use a microcontroller unit (MCU) as the core in the control system cooperating with the functional generator chip MAX038 and SG3525 to output the desired PWM waveform...
The DC current rejection of a single phase half-bridge grid-connected inverter with a line-frequency isolation transformer is researched in this paper. The impact of the magnetic dc bias of the transformer is given out from the mathematic model of the transformer in current-mode control. For the half-bridge current-mode inverter, the dc current rejection method is presented based on the relationship...
Nowadays, most of the electrical railway tractions, especially the high-speed tractions are using AC-DC-AC power driving system. The best choice for the AC-DC link is four-quadrant PWM rectifier, which can provide controllable DC link voltage and better power factor for the grid. In high power drive applications, the switch frequency of the power semiconductor device cannot be very high, usually less...
Firstly, it introduces the different operating modes and control mechanism of the high-voltage DC transmission (HVDC) system and analyzes the fuzzy control theory. On this basis, using MATLAB, a typical 12-pulse HVDC transmission system model of the bridge has been simulated under the control of traditional PI and fuzzy intelligent respectively. Compared with the traditional control methods, the real-time...
By analyzing luminous process and volt-ampere characteristics of gas discharge lamp, a piecewise linear regress mathematical model is proposed. An illuminated loop-locked intelligent adjust light controller is designed by using power switching devices and SPWM variable voltage variable frequency controlling means. The above design can modify pulse and control carrier-to-noise ratio. Within a certain...
PWM rectifier technology is introduced to the main Power Circuit of the charger for aircraft battery to enhance the charging efficiency of aircraft battery and improve its long term reliability and save its life in this paper. A new strategy of DPC Based on the Space Vector Modulation (SVM) is used in PWM rectifier, Meanwhile, a fuzzy PI controller is designed in DC voltage control loop. The simulation...
In the actual power system three-phase voltages are distorted and asymmetric and contain a large number of negative sequence components. Traditional ip-iq method which detect harmonic currents based on instantaneous reactive power theory will be inaccurate, so the positive sequence voltage component of A-phase need be extracted. Improved instantaneous symmetrical components structured a rotary phases...
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