简述彩电保护执行电路与保护显示电路(上)

一、保护执行电路保护执行电路是保护电路的终端电路,接到保护电压翻转电路送来的保护控制电压后,保护执行电路动作。常见的保护电路大多通过以下途径达到保护的目的。1.由待机电路执行保护这种保护电路是目前应用最多的保护执行电路之一。传统的保护电路,特别是由分离元件组成的保护电路,保护翻转电路产生的保护控制电压直接送到待机控制电路中,迫使待机控制电路动作,整机进入待机或关机状态;新型彩电的保护电路,保护翻转电路产     

彩电保护电路基础知识与故障检测电路(一)

一、保护电路基础知识彩色电视机中的电源电路、行输出电路、伴音功放电路、场输出电路等,工作于高电压或大电流状态,故障率较高,且上述电路的损坏,往往波及其他电路连锁损坏。为了避免故障扩大,在彩色电视机中,多设有保护电路,对上述高电压、大电流电路的工作状态进行监测,当被监测电路发生过压、过流等现象时,采取保护措施。彩电中的保护电路结构大多由故障检测电路、电压翻转电路、保护执行电路三部分构成。故障检测电路对被检测的电压或电流进行检测,并将检测结果送到     

储能系统用锂离子电池保护电路的研究

针对一般锂电池保护电路的缺陷,率先在锂电池保护电路加入了温度保护电路,均衡电路,下限自锁电路,电量显示电路。温度保护电路有效地保护了放电场管;均衡电路的加入保护了电池的一致性;下限自锁使得电源系统更加稳定;电量显示电路使得电路的能量系统更加直观;实验结果验证了锂电池保护系统设计的正确性。     

松下CR—VM6553H型车载一体机原理概述

松下CR—VW6553H型车载一体机按照电路结构分为主板电路和液晶显示驱动电路。其中,主板电路包括：电源电路,CPU系统电路,AV信号选择与收／放音共用电路,GPS与DVD／CD换片机接口电路,收音组件与数字调谐锁相环电路等;液晶显示驱动电路包括：OSD字符形成电路,D／A缓冲电路,视频处理与时序控制电路,DC—DC供电电路,DC-AC升压逆变电路等。     

跟我学彩电加装遥控器的技术(2)

4.接口电路徒弟:何谓接口电路?为什么遥控彩电都没有接口电路?师傅:接口电路是指微处理器与电视机之间相衔接的电路。由于遥控彩电都采用微处理器控制电路,微处理器是一种数字信号处理电路,而电视机则是模拟信号处理电路,因此,微处理器对电视机电路的控制,需要一些转换电路,主要是进行电平转换,这些转换电路称之为接口电路。     

手机锂电池无线充电器设计

采用电磁感应原理对手机锂电池无线充电器进行设计,本设计分为发射电路和接收电路两部分。发射电路包括功放电路、振荡电路、耦合线圈;接收电路包括耦合线圈、整流电路、滤波电路和恒压充电电路。对电路中各元器件进行了设计、选型与制作。实验结果表明,所设计的无线充电器可以对手机电池进行充电,电路正确可行。     

黑白电视机检修讲座6

八、场扫描电路与前面介绍的行扫描电路相对应,黑白电视机的场扫描电路是使显像管中的电子束能在垂直方向进行偏转动作的职能电路。该电路主要由整形放大电路,场振荡电路,场放大、场推动和场输出电路组成。典型应用电路如图12所示。     

彩电常见保护电路故障检修有诀窍(一)

现代彩电中的保护电路大体结构通常由故障检测电路、电压翻转电路、保护执行电路三部分构成。保护电路工作原理是:故障检测电路对被检测的电压或电流进行检测,并将检测结果送到保护电压翻转电路,当被检测的电压或电流超过设定值时,检测电路将检测后的故障信息送往保护电压翻转电路,产生保护控制电压,驱使保护执行电路动作,迫使被保护电路退出工作状态或进入相应的保护状态,达到保护的目的。图1是比较常见的正规的保护电路结构图,在实际的彩电保护电路中,根据需要有所增减。如:有的故障检测电路兼作电压翻转电路,有的电压翻转电路,兼做保护执…     

等离子彩电电源电路的基本结构和检修流程(一)

等离子电视机的电源电路是将交流220V电压经整流、滤波变换和处理变成多种直流电压,为整机的各种电路供电,如接口电路、音频信号处理电路、视频信号处理电路、数字信号处理电路以及等离子屏等电路都需要供电,它是等离子电视机中最重要的电路。一、电源电路的基本结构和电路分析等离子电视机的电源电路可以输出电视机所需的各种电压,其电路结构也比较复杂,图1所示为长虹     

录音机和组合音响函授班辅导材料

辅导材料(7) 本月份学习组合音响教材的第五、六章内容,主要内容和要求如下: (1)掌握功率放大器电路、电源电路、保护电路和LED指示器电路的工作原理,学会这些电路的故障分析方法。 (2)了解遥控电路工作原理,了解音响电路的组成和各部分电路的具体作用。 一、主功率放大器等电路分析方法和注意点 (1)学习OTL功放电路应以分立元器件电路开始,它是OCL、BTL功放电路的基础;是集成电路     

基于并联负载发夹型谐振器的四阶带通滤波器

针对现代无线通信系统中平坦带通滤波器的需求,提出了一种并联负载的发夹型谐振器,并利用提出的谐振器构建了四阶平坦带通滤波器。首先,通过在发夹型谐振器磁场最强的位置（中心位置）设置电阻,设计了一种新的并联型谐振器,从而可以通过改变电阻值来灵活地调整固有品质因数;其次,采用具有高、低固有品质因数的耦合拓扑来构建四阶平坦带通滤波器。最后,在印刷电路板上制备了一个具有传输零点和平坦带通的四阶带通滤波器。实验结果表明,该四阶带通滤波器的实测结果与仿真结果吻合较好,与其他多阶带通滤波器相比,该四阶带通滤波器具有可灵活控制的固有品质因数和小于0.2dB通带平坦度。     

新型双频窄带带通滤波器的设计

提出了1种新型双频窄带带通滤波器,由1段1/4波长的均匀阻抗线以及1/2波长的U型阶跃阻抗谐振器组成,输入输出采用抽头式.所设计滤波器中心频率为2.4/5.6 GHz,为无线通信系统中的常用频率.该滤波器的带外有3个传输零点的引入,增强了通带隔离度以及阻带的抑制特性,带内回波损耗低于-0.3 dB.双频窄带带通滤波器的...     

Compact third-order microstrip bandpass filter designed by the distributed- to lumped-element equivalence

In reality, it is not easy to design microstrip filters for the sake of distributed-element effect. It is an effective approach to approximate distributed-element structures through appropriate lumped-element circuits. In this paper, some basic microstrip structures are discussed, whose equivalent lumped-element circuits are derived. Then, a novel microstrip filter is obtained by connecting these microstrip structures, according to the similar topology of the third-order lumped-element bandpass filter. The equivalent lumped-element counterpart of the proposed microstrip filter clearly reveals its physical mechanism, ie, how the resonances are created and coupled and how the transmission zeros are created. Furthermore, a set of the design formulas are presented, which can be used to calculate initial structure parameters and then facilitate design process. The proposed microstrip bandpass filter can realize a third-order elliptic bandpass response with one transmission zero at each side of the passband. In addition, two short-circuited stubs are added to input/output ports to create the third transmission zero. The filter is featured by good frequency selectivity and out-of-band suppression. For demonstration, an actual example was designed, fabricated, and measured.     

电流模式八阶带通滤波器设计

本文提出了实现电流模式八阶带通滤波器的新方法,该法采用第二代改进式电流传送器构成的二阶电流模式带通滤波器作为基本积木块,得出了电流模式八阶带通滤波器的跳耦实现电路。该设计电路所有电阻,电容均接地,有利于电路集成化。     

A novel laboratory approach for analyzing periodic signals

An experimental approach is presented for measuring the (root means square) values of the harmonics contained in a periodic signal by using an active bandpass filter. Instead of electronically sweeping the filter center frequency by the input harmonics, the filter center frequency is held constant and the input fundamental frequency is decreased manually, causing each input harmonic to be swept through the bandpass filter response     

基于ADS的一种高指标带通滤波器设计

介绍了平行耦合线微带带通滤波器的基本原理,提供了一种基于ADS软件设计高指标平行耦合线微带带通滤波器的实例和详细设计步骤,并给出了仿真结果以及ADS优化步骤和原则.     

Recursive algorithm for real-time measurement of electrical variables in power systems

In this paper, a novel complex bandpass filter is presented which overcomes the pitfalls of the techniques in common use. This complex bandpass filter can correctly extract the phasor of the fundamental component and symmetrical components in voltage or current waveforms and then accurately estimate their instantaneous amplitude, phase angle, and frequency, even encountering various power disturbances. Further, a recursive algorithm is also developed for the complex bandpass filtering that updates current filtering output only using several previous sample values and filtering outputs. This attribute greatly reduces the computational complexity of complex bandpass filtering, which is the weakness of the continuous wavelet transform based on the well-known Morlet Wavelet. Thus, this recursive algorithm is highly desirable for real-time applications. The performance of the proposed technique is ascertained by using both simulated and practical power disturbance waveforms.     

CASCADE SYNTHESIS OF MONOLITHIC CRYSTAL FILTFRS POSSESSING FINITE TRANSMISSION ZEROS

A simple method for the synthesis of bandpass or bandstop filters possessing finite transmission zeros as a cascade of shunted double-resonator monolithic crystal filter (MCF) sections is given. The lowpass or highpass prototype transfer function is synthesized as a cascade of MCF prototype sections for which explicit expressions for the element values are given. Application of the narrow-band lowpass to bandpass frequency transformation to the prototype network then yields a physically realizable filter with the desired bandpass or bandstop response. An example of the synthesis of a bandstop filter is given to illustrate the approach.     

A reconfigurable bandpass-bandstop filter based on varactor-loaded closed-ring resonators [Technical Committee]

In this article, a novel reconfigurable bandpass-bandstop filter based on the varactor-loaded closed-ring resonators is presented, where the bandpass and bandstop characteristics can be easily controlled by tuning the varactor bias voltage. This reconfigurability results from the perturbation effect on the degenerated even and odd modes of the closed-ring resonator. When the perturbation varactor is at the series resonance, its reactance vanishes, so a bandstop characteristic is formed. When the perturbation varactor is changed to be capacitive, the bandpass characteristic is generated. Additional varactors, incorporated at input and output ports, are tuned along with the perturbation varactors to maintain good return losses.     

开关电容椭圆低通滤波器的设计与仿真

本文结合八阶椭圆低通滤波器的设计,讨论了开关电容滤波器计算机辅助设计的一种有效方法。将开关电容网络的时变拓扑,变换为时不变拓扑,建立开关电容模拟电阻的Z域模型,与电容、运算放大器模型结合,构成二阶开关电容椭圆滤波器。将二阶开关电容滤波器级联,给出了八阶开关电容椭圆低通滤波器的设计与PSPICE仿真程序。仿真输出曲线显示了椭圆低通滤波器的陡峭衰减特性和理想幅频特性,符合设计要求。适用于高通、带通、陷波等各种滤波器的设计与仿真。