A generalized program for extracting the control characteristics ofresonant converters via the state-plane diagram

This paper presents a generalized computer program that can be used to derive the control characteristics of resonant power converters from their state-plane trajectories. It has been shown that the geometrical properties of the state-plane trajectory can be used to derive the control characteristics of a given resonant power converter topology. These characteristics are essential in determining the design parameters such as power converter gain, component stresses and required feedback controllers. The main program consists of several subroutines, each of which is associated with a segment of the state-plane trajectory. Such a program will make it faster and easier for a design engineer to obtain the design parameters of any given resonant topology     

新型指令变换器测试系统设计

指令变换器是测试飞行器工作参数和各路信号的关键设备,故设计一种新型的测试指令变换器工作的系统。该系统采用FPGA为主控制芯片,设计了4个模块,其中综合模块解析转发命令与数据,与其他3个模块配合接收和输出测试所需信号,包括48路电压可调的直流量模拟信号,8路时统信号以及PCM数据。试验结果表明,该系统可靠性高,性能稳定。     

Three-phase AC-to-AC series-resonant power converter with a reducednumber of thyristors

Power pulse modulation with internal frequencies of tens of kHz and suited for multikilowatt power levels is applied to a series-resonant converter (SRC) system for generating synthesized multiphase bipolar waveforms with reversible power flow and low distortion. The high pulse frequency allows the application of the principle of modulation and demodulation for fast system response. The use of an SRC for power transfer and control obtains natural current commutation of the thyristors and the prevention of excessive stresses on components. Switches with bidirectional current conduction and voltage blocking ability are required. The conventional series-resonant AC-AC converter applies a total for 24 antiparallel thyristors. An alternative circuit configuration for the series-resonant AC-AC converter with only 12 thyristors is presented. Use of the converter results in a higher efficiency and lower costs     

混合集成电路DC/DC变换器的设计与应用

传统的采用分离器件设计的电源变换电路具有很多缺点:电路设计与开发周期冗长;由于具有较高的寄生参数,电路性能较低;所设计电路具有较大的解决方案尺寸;器件选型困难;分离器件较多,系统电路存在可靠性问题.     

Design basis and characteristics of a special frequency-voltage convertor circuit

The requirements and characteristics of a frequency-voltage converter are established, together with the effect of a separate input variable T. Using the developed expressions, a computer program has been constructed so that accurate output predictions are readily available.     

4模余数系统反向转换器设计

反向转化已经成为制约剩余数系统发展的瓶颈问题,尤其对于模集合个数多于3个的模集合。针对4基数模集合{2n,22n+1,2n+1,2n-1},在新中国余数定理Ⅰ的基础上,提出了一个新的高效并行转换算法。该算法可同时处理4个模,处理数的动态范围达到5n位,乘法逆元全部采用闭合形式,电路完全基于加法器构成,硬件实现容易。理论分析表明,与同类模集合反向转换器相比,大大降低了对硬件电路的要求,明显减小了转换器的面积和电路延迟,提高了转换效率。     

New voltage-to-frequency convertor with nonlinearity correction

In the voltage-to-frequency convenor presented, the non-linearity error due to the finite discharging time of the integrating capacitor is compensated by using the comparator threshold correction method, in a very effective way. The convertor itself consists of only one op-amp, which performs both functions of integration and comparison.     

Inductor realisation with a negative-impedance convertor

A circuit consisting of a negative-impedance convertor, suitable for the realisation of an inductor, is presented. For a certain circuit condition the realisation is independent of frequency, and by the variation of a single capacitor the inductance value of the inductor can be varied over a wide range while the resistive part remains constant. Both the inductance and the associated resistive part are shown to be frequency-dependent if this condition is not exactly satisfied.     

Steady-state analysis of a series-resonant DC-DC converter with abipolar power flow

A time-domain analysis for the steady-state model of a series-resonant power interface for both step-up and step-down modes is presented. The exchange of electrical energy between a source and the resonant circuit in order to stabilize the stored electrical energy is defined. The characteristics of a series-resonant converter with bilateral power flow are presented in normalized form, described by the output characteristics. The results obtained in a four-quadrant motor drive illustrate the characteristics of a high-frequency power interface     

Simple voltage-to-frequency convertor with increased frequency range

Conventional free-running multivibrators are frequently used as voltage-to-frequency convertors, although the fmax/fmin ratio of this circuit is rather small. A free-running multivibrator with complementary transistors has advantages concerning this ratio as well as regards some other convertor parameters.     

Regulated self-oscillating convertor with auxiliary feedback circuit

A regulated self-oscillating transformer-coupled d.c./d.c. convertor is presented which has an auxiliary feedback loop to sustain self oscillations. While this circuit retains the inherent simplicity of self-oscillating circuits, it avoids certain starting problems which are usually encountered if transformer coupling is inserted into the self-oscillating feedback loop.     

基于PWM降压转换器AP3003的车载充电器

随着电子技术的不断发展,移动多媒体设备正逐渐成为人们生活中不可缺少的工具,与这些产品相对应的充电器设计也越来越受到关注.     

A study of series-resonant DC/AC inverter

A new DC/AC inversion for achieving an AC sinusoidal waveform synthesized by a series of quasi-sinusoidal pulses is described. A modified pulse-width-modulated (PWM) controller is presented for driving the power switch to operate in a forced discontinuous-conduction mode (FDCM) so as to achieve series-resonance in the power stage. The output power results mainly from the energy stored in the resonant capacitor and is independent of the number of the resonant quasisinusoidal pulses. Three dynamic conversion states including charging, resonant, and RC-discharging states are modeled and analyzed. Signal analysis for the composite AC sinusoidal waveform is conducted. A small-signal model for system performance investigation is described. A prototype of a 1 kW DC/AC inverter is examined by simulation and experimentation in order to assess the system performance     

Fast measuring frequency-to-voltage convertor with DC output

A new frequency-to-voltage conversion scheme is presented, which offers fast dynamic response and nomially zero output ripple, even when operating with low-frequency inputs. Circuit simplicity and overall performance make this convertor highly suitable for low-frequency applications in instrumentation, measurement and control systems.<>     

Design of a circulating-type analogue?digital convertor using bucket-brigade delay lines

A hardware implementation of a circulating-type analogue?digital convertor using bucket-brigade delay lines (b.b.d.l.) is described. The b.b.d.l. used is a 32-stage commercially available device. This large number of stages is not necessary, and, in practice, a b.b.d.l. with two or three stages would be satisfactory. Such an analogue?digital convertor can be implemented economically, and would be able to convert input signals in the frequency range 0?500 kHz. The principal advantage in using the b.b.d.l. is in the reduction of the number of analogue switches required. Experimental results show that 4?6 bit conversion is readily achieved, although a compensator network to compensate for the b.b.d.l. losses is required.     

Frequency/voltage convertor with low output ripple

A circuit is desdribed which performs linear frequency-to-voltage conversion with nominally zero output ripple and, at one frequency, ideal step response. This is in contrast to conventional convertors which have large output ripple, the removal of which necessarily produces slow response.     

Microwave parametric upper-sideband down convertor with conversion gain

For the first time a parametric upper-sideband down convertor is introduced at R-band. It has a noticeable large frequency conversion ratio from 34 GHz to 3 GHz, producing a transducer gain GT=5.8 dB if a resistive image termination is used.     

A multiphase series-resonant converter with a new topology and areduced number of thyristors

Multiphase series resonant (SR) power converters provide a flexible way to transform power between a utility grid and a multiphase load or source. The current implementations all suffer from a high component count, which makes the use of these power converters unattractive from an economical point of view. A new topology for multiphase SR power converters has been proposed in the literature in a simulation context. This topology uses half the number of power semiconductors compared to the existing multiphase SR power converters. The present paper addresses the implementation of the new topology in a prototype power converter. The old and new topologies are presented. The operation of the new topology is explained. In the new topology the resonant circuit is grounded at one side, which compared to the old topology imposes a restriction on the operation. The paper shows both simulation data and measured waveforms. It is explained that the economical gain due to the reduction in component count is offset by a lower power rating. The paper finishes with conclusions and acknowledgments     

New constant frequency PWM dual convertor with synchronous rectifier

A new constant frequency PWM dual convertor which has fully regulated dual outputs is proposed. The proposed convertor is the superposition of a forward convertor and a flyback convertor. The switches in the forward convertor for synchronous rectification provide another degree of freedom in controlling the flyback convertor. Thus, not only forward output but also flyback output can be fully regulated by constant frequency PWM control in continuous conduction mode (CCM).<>