对RLC串联电路中通频带与RLC参数关系的讨论

讨论了ＰＬＣ串联电路中通频带与ＲＬＣ参数的关系，说明在设计一个ＲＬＣ串联谐振电路时，在给定谐振频率，电感量和频带宽度时，上下边界是频率不能只满足通频带宽度而任意假定，还应满足通频带与ＲＬＣ这些参数之间关系的表达式。     

单片机控制的RLC测量仪研制

提出以8031单片机系统为核心的RLC智能测量仪的设计制作方法.该仪器所采用的测量思路是先把电路参数R,L,C转换成频率信号f,然后用单片机计数,再运算求出R,L,C的值,最后送显示器显示.这样就把较难测量的物理量转变成了精度较高且较容易测量的物理量.     

基于FPGA的半球谐振陀螺频率跟踪技术

半球谐振陀螺谐振频率的跟踪精度与稳定性很大程度上决定了陀螺的性能。通过分析半球谐振陀螺的频率特性以及锁相环基本原理,设计了基于锁相环的半球谐振陀螺频率跟踪方案,并用FPGA进行全数字化实现。半球谐振陀螺采用真空封装,内部温度难以测量,然而其谐振频率与温度具有很好的线性相关性,因此可采用谐振频率对陀螺温度进行测量。传统的频率跟踪方案一般采用模拟锁相环实现,其缺点是频率值隐含于输出的正弦波中,无法供后继测量模块使用,本文所设计的FPGA全数字方案可弥补这一缺陷。根据陀螺谐振频率与温度之间的关系,给出了利用跟踪频率测温的分辨率公式并进行了相关实验。实验结果显示,谐振频率为4440Hz时频率跟踪稳态相对误差可达10-7量级,利用跟踪频率测温的分辨率可达0.0042℃。     

串联输出DC／DC谐振变换器的稳态分析

分析了高于谐振频率工作的串联输出谐振变换器的工作模式,采用状态变量法计算获得了若干描述稳态工作的特性曲线,为分析和设计这种变换器提供了基础     

半球谐振陀螺控制电路频率跟踪精度提升方法

半球谐振陀螺控制电路的控制精度直接影响半球谐振陀螺仪的输出精度,而频率跟踪精度又直接影响了半球谐振陀螺控制电路的精度.传统的半球谐振陀螺数字控制电路采用过零比较的方法计算陀螺幅点信号的频率,此方法易受地线毛刺信号的干扰,频率跟踪精度不高.介绍了采用A/D转换采集数据估算陀螺幅点信号频率的方法,并对各种方法进行了优缺点比较,提出选用建议.这些方法既提升电路抗干扰能力,又大幅提升了频率跟踪精度,还省去了过零比较电路.分析及测试结果表明,采用该频率跟踪方法,半球谐振陀螺的频率跟踪精度可达0.002Hz,可大幅提升半球谐振陀螺控制电路的精度.     

基于自适应陷波滤波器的伺服系统谐振频率估计及抑制

在使用陷波滤波器抑制伺服系统机械谐振时,需要获取准确的机械谐振频率。为了快速检测出谐振频率,提出了一种基于自适应陷波滤波器(ANF)的机械谐振频率估计算法,通过速度误差信号分析,实现谐振频率在线快速辨识。首先,建立柔性连接伺服系统模型；然后,对ANF频率估计算法进行分析,并且与常用的快速傅里叶变换(FFT)频率检测算法的分析精度和计算速度进行对比。数值比较和仿真验证表明,ANF频率估计算法可以更快地实现谐振频率的精确检测。最后搭建试验平台,以ANF频率估计的结果作为陷波器的中心频率,成功实现了电机转速振荡的抑制,验证了该方法的有效性。     

谐振式光子晶体光纤陀螺环路建模与仿真

为减小谐振式光子晶体光纤陀螺系统中相对频率噪声对随机游走系数的影响,在反馈回路中引入PI控制器构成新反馈回路。通过建立谐振式光子晶体光纤陀螺环路模型,优化反馈控制模型中PI控制器参数,仿真得到谐振式光子晶体光纤陀螺的闭环带宽可达39.1k Hz,响应时间为1.24×10~(-4)s,超调量控制在8%以内。利用上述结果对谐振式光子晶体光纤陀螺进行检测带宽的优化设计仿真,得到当系统检测带宽小于3Hz时,可控频率噪声功率谱密度小于1.3μW/Hz,对应的随机游走系数(RWC)小于0.001(°)/h~(1/2),满足导航级陀螺系统的精度要求。     

结构刚度对带惯性负载的阀控马达随动系统的影响

在阀控马达随动系统中,执行元件(阀与马达)和负载(传动装置与转台)的惯性、结构刚度,决定了系统的结构谐振频率。本文寻求结构谐振频率与系统参数的关系。     

基于PSO算法的半球谐振陀螺惯导系统陀螺温度补偿方法

针对半球谐振陀螺受温度影响出现零位漂移的问题，以测温电路温度为基准，建立温度频率函数实时解算温度，提出一种基于粒子群优化(PSO)算法的半球谐振陀螺惯导系统陀螺温度补偿方法。在求解温度时，需要先将温度频率函数转换为一元三次方程，存在测试计算量大的问题。引入逆向拟合思想，建立频率温度函数，提高陀螺输出温度实时性和降低测试计算量，替代了传统陀螺测温硬件电路，为惯导系统轻小型设计提供新思路。考虑温度变化、温度变化率以及两者的交叉项，建立温度补偿模型，引入PSO算法求解模型系数。温度试验结果表明，在温箱温度为-40~50 ℃内，补偿后的半球谐振陀螺的零偏稳定性较补偿前提升了46％。     

谐振电路中品质因数的计算方法

从品质因数的原始定义出发,分别计算出简单RLC串、并联电路的品质因数,得到两个结论,并将其推广,提出了两种简单的计算品质因数的方法,最后通过求解一个实际的LC并联谐振电路的品质因数得到验证。     

Maximum Power Transfer for Full-Wave Rectifier Circuits

An analysis is done to determine the maximum power transfer conditions for full-wave rectifier circuits. Potential applications noted are implanted medical instruments, inductive power transfer to weapons, power transfer using space reflectors, and power generation in space. Three types of series impedances are considered: resistive/inductive (RL), resistive/capacitive (RC), and resistive/inductive/capacitive (RLC). The optimum ratio of ac-to-dc voltage output is determined for each type. For the case that involves all three impedance types, the optimum turning condition is also determined. The differential equations describing the circuits are solved in nondimensional form. The solutions involve partial differential equations, closed-form relationships, and simultaneous equations that are solved by numerical methods. The optimum ratio of peak ac-to-dc voltage ranges from 2.0 to 2.8, depending upon the circuit. The optimum turning differs significantly from the usual resonant conditions, especially for low Q.     

压电元件在悬臂梁振动被动控制中的实验研究

应用阻尼技术提高结构系统的阻尼是一种十分有效的振动控制方法。根据压电元件的压电效应及其具有的电容特性，设计压电吸振器，即根据被控结构，设计RLC谐振回路，把机械结构的机械能通过回路中的电阻热能消耗掉，达到吸振的效果。用实验方法对两种谐振方案进行验证分析，得到一些指导性的结果。     

A Normalized Model for the Half-Bridge Series Resonant Converter

Closed-form steady-state equations are derived for the halfbridge series resonant converter with a rectified (dc) load. Normalized curves for various currents and voltages are then plotted as a function of the circuit parameters. Experimental results based on a 10-kHz converter are presented for comparison with the calculations.     

Relationships Among Classes of Self-Oscillating Transistor Parallel Inverters

It recently has been shown in the literature that many dc-to-squarewave parallel inverters which are widely used in power-conditioning applications can be grouped into one of two families. Each family is characterized by an equivalent RLC network. Based on this approach, a classification procedure is presented for self-oscillating parallel inverters which makes evident natural relationships which exist between various inverter configurations. By utilizing concepts from the basic theory of negative resistance oscillators and the principle of duality as applied to nonlinear networks, a chain of relationships is established which enables a methodical transfer of knowledge gained about one family of inverters to any of the other families in the classification array.     

Limiting the Impulsive Noise in a PLL

This paper analyzes the operation of a phase-locked loop (PLL) preceded by a bandpass limiter (BPL) in the presence of impulsive noise. It is shown that the effect of the limiter consists essentially in a change of the statistics of the pulse strengths of the noise, so that the behavior of a BPL + PLL can be deduced from that of a simple PLL by suitable adjustment of the noise model. It is found that the limiter greatly enhances the PLL performance by reducing both the phase-error variance in the loop and the probability of cycle slippage. Finally, the design of the filter of the BPL is discussed, resulting in the conclusion that the best results are obtained by using a singletuned RLC circuit.     

一种STC电路的实现方法

本文介绍一种适合机载气象雷达的比较完善的 STC 电路的实现方法。它与现行气象雷达 STC 电路的不同之处在于:用多级不同时间常数的指数形成电路产生 STC 电压,控制变容二级管组成的电容电桥的衰减,主中放采用差分放大器。这种 STC 电路实现方法除了在 STC 范围内改变接收机的增益外,不影响整机的其它参数,本文讨论了有关电路的工作原理。     

用热流探针测量激波速度

激波速度测量是激波管和激波风洞运行状态的一个重要参数,压电传感器或光学方法测速系统成本高,而传统电离探针在激波马赫数较低、波后温度达不到空气电离程度的情况下无法满足实验要求。提出了一种使用同轴热电偶作为测速探针来测激波速度的方法,弥补了电离探针在激波马赫数较低时的不足。介绍了同轴热电偶探针测速原理,并设计了测量激波速度的系统电路。通过信号放大电路锁定激波冲激信号,触发脉冲信号发生电路,实现了一种单通道、多测点的激波风洞测速系统。分别开展以温度与热流为触发信号的风洞实验,结果表明只有使用热流信号才能满足激波测速的时间要求。     

Nonlinear Analysis of a Family of LC Tuned Inverters

four widely used self-oscillating dc-to-square-wave parallel inverters which employ an inductor-capacitor tuned network to determine the oscillation frequency are reduced to a common equivalent RLC network. The techniques of singular-point analysis and state-plane interpretations are employed to describe the steady-state and transient ient behavior of these circuits and to elucidate the three possible modes of operation: quasi-harmonic, relaxation, and discontinuous. Design guidelines are provided through a study of the influence of circuit parameter variations on the characteristics of oscillation and on frequency stability. Several examples are provided to illustrate the usefulness of this analysis when studying such problems as transistor emitter-to-base junction breakdown during oscillations and the design of starting circuits to insure self-excited oscillations in these inverters.     

一种高分辨率积分输出的A/D转换电路的设计

针对通常需要高分辨率的模数转换的导航领域,描述了一种高分辨率积分输出的A/D转换电路的设计,论述其工作原理和软硬件设计方案。通过电路仿真和试验分析表明,这种A/D转换电路的设计兼具V/F转换的高精度和A/D转换的高速输出的优点。