液晶面板常用接口介绍(三)

③图14为10通道LVDS发送IC框图,见图14所示。④液晶面板的输入信号中都必须要有DE(数据选通)信号,但有的液晶面板只使用单一的DE信号而不使用行、场同步信号。因此应用于不同的液晶面板中时,有的LVDS(低压差信号)发送IC可能只需输入DE信号,而有的同时输入DE和行、场同步信号。(2)输入时钟信号输入时钟信号即像素时钟信号,也称为数据移位时钟(在LVDS发送IC中,将输入的并行RGB数据转     

电磁炉常用元件介绍

1.晶振 晶振在电磁炉中用作单片机的时钟信号，时钟信号也是整个电磁炉的工作核心信号。如果电磁炉没有时钟信号的输入，那么整机将无法启动工作。     

TCL王牌等离子(PDP)4226H/42U3H型彩电驱动电路分析(四)

①使用的控制信号:CLK:移位时钟,输入行扫描时钟。DA:移位寄存器的串行数据输入,输入扫描信号,低电平有效。DB:移位寄存器的串行数据输出,输出扫描信号到下一片IC。LE:数据输出锁存信号。OC1和OC2:高压输出端输出状态选择信号,用来允许或禁止扫描信号输出。     

电磁炉常用元件介绍

1.晶振晶振在电磁炉中用作单片机的时钟信号,时钟信号也是整个电磁炉的工作核心信号。如果电磁炉没有时钟信号的输入,那么整机将无法启动工作。晶振的封装形式有金属封装、塑料封装、环氧树脂封装。电磁炉常用的晶振频率有     

国产彩电常用微处理器(CPU)关键引脚数据速查表

┏━━━━━━━━━━━┳━━━━━━━━━━━━━━━┳━━━━━━━━━━┳━━━━━━━━━━━━━━━━┳━━━━┳━━━━━━━━━━━━━┓┃ ┃ 主电源控制端 ┃复位输入端 ┃ 时钟振荡器 ┃供电 ┃ 备 注 ┃┃ ┣━━━┳━━━━━┳━━━━━╋━━━━┳━━━━━╋━━━━┳━━━━┳━━━━━━┫ ┃ ┃┃ CPLI型号 ┃ ┃待机电 ┃开机电 ┃引脚 ┃工作电 ┃输入 ┃输出 ┃时钟频 ┃引脚 ┃ ┃┃ ┃引脚 ┃压(V) ┃压(V) ┃ ┃压(V) ┃引脚 ┃引脚 ┃率(MHz) ┃ ┃ ┃┣━━━━━━━━━━━╋━…     

3Gbps的LMH0346高清晰度／标准清晰度时钟恢复器

LMH0346是业界体积最小、功耗最低、抖动最少的3Gbps SDI时钟恢复器。这款芯片可以自动检测输入信号,并为信号重新定时,以减低高频抖动。LMH0346芯片是唯一一款无需加设输入多路切换器的分立式单通道3Gbps SDI时钟恢复器。由于无需加设输入多路切换器,因此美国国家半导体可将引脚数目减少至竞争产品的三分一,以及将封装体积缩小一半。此外,其     

基于SOPC技术的多功能时钟同步装置

研究并设计了多功能的GPS时钟同步装置,该系统采用Altera公司的SOPC解决方案,配以GPS信号接收模块,可以准确地同外部输入GPS信号自动保持同步,频率和相位都能独立可调,能自动判断输入信号的频率,并向电子式互感器和电子式互感器校验仪提供同步时钟.经过多次现场试验表明,该装置达到了设计要求,取得了较好的应用效果.     

TCL王牌MS89机芯液晶彩电检修要点及案例(二)

(6)HDMI信号输入HDMI(高清晰度多媒体接口)信号由插头P1输入,分为1对时钟对信号和3对数据对信号。P1的輰訛輥、⑩脚输出的HDMI_RXC-、HDMI_RXC+时钟对信号,经R317、R316后,连接到U9的①、②脚。P1的⑨脚/⑦脚、⑥脚/④脚、③脚/①脚输出的     

基于GPS授时的电网频率测量技术的研究

提出了一种基于GPS授时的电网频率测量的新方法,系统以GPS接收机提供的1PPS信号为基准源,结合GPS时钟信号和恒温晶振时钟信号精度互补这一特性,通过调控恒温晶振的压控端,使其输出频率随之改变,以维持短期和长期的时钟精度和稳定性。然后将此时钟提供给DSP的定时器,通过DSP的e CAP模块对输入信号的上升沿进行捕获,记录两个上升沿的触发时间得到电网的实时频率。     

一种新型数字式相位仪

本文提出一种利用双斜原理组成的简便数字式相位仪。同时,给出了与测量过程中使用的输入波形频率或时钟频率相独立的数字输出数值。数字式相位仪在二个输入波形周期中完成一次测量。     

Unit commitment using Lagrangian relaxation and particle swarm optimization

Unit commitment (UC) is a NP-hard nonlinear mixed-integer optimization problem. This paper proposes ELRPSO, an algorithm to solve the UC problem using Lagrangian relaxation (LR) and particle swarm optimization (PSO). ELRPSO employs a state-of-the-art powerful PSO variant called comprehensive learning PSO to find a feasible near-optimal UC schedule. Each particle represents Lagrangian multipliers. The PSO uses a low level LR procedure, a reserve repairing heuristic, a unit decommitment heuristic, and an economic dispatch heuristic to obtain a feasible UC schedule for each particle. The reserve repairing heuristic addresses the spinning reserve and minimum up/down time constraints simultaneously. Moreover, the reserve repairing and unit decommitment heuristics consider committing/decommitting a unit for a consecutive period of hours at a time in order to reduce the total startup cost. Each particle is initialized using the Lagrangian multipliers obtained from a LR that iteratively updates the multipliers through an adaptive subgradient heuristic, because the multipliers obtained from the LR tend to be close to the optimal multipliers and have a high potential to lead to a feasible near-optimal UC schedule. Numerical results on test thermal power systems of 10, 20, 40, 60, 80, and 100 units demonstrate that ELRPSO is able to find a low-cost UC schedule in a short time and is robust in performance.     

Negotiating expert status: who gets taken seriously

A lay person may listen puzzled as a specialist in a public hearing discusses a technical point. Similarly, a challenging question from a technically knowledgeable member of the audience may be difficult to fathom. Failure to understand what a speaker discusses-despite one's interest in a topic-can cause frustration, anger and despair. It makes a listener wonder why they are there trying to engage, and why technical specialists persist in such a style of presentation. Breakdowns in communication between technical and nontechnical people are linked to the concept of “expert”. This link involves the process of the “negotiation of expert status”; this refers to the social construction of the role of the “expert” by the participants in a conversation. The term “negotiation” refers to the sometimes subtle and sometimes overtly contentious nature of a debate about who deserves to be listened to as a voice of authority on a particular topic     

Effect of Prefault Load on Field Overvoltages in Rectifier-Excited Synchrondus Machine During Sequential 3-Phase Fault

ABSTRACT

In a Synchronous machine with rectifier excitation, large reverse voltages may be induced across the field during a transient condition when the field current tends to flow in the reverse direction and is blocked by rectifiers. Earlier investigation on an initially unloaded machine showed that a sequential 3-phase fault, in which a line to line fault develops into a 3-phase fault after a short time, produces field overvoltages whose magnitudes may be comparable to those due to line to line fault. In this paper, analysis has been carried out to estimate the magnitude of the field overvoltage during a sequential 3-phase fault when the machine is assumed to operate on a prefault load. Numerical results show that a sequential 3-phase fault on a machine having prefault loads may be much more severe compared to a line to line fault from the field overvoltage point of view. The results also indicate that very large field overvoltages may be produced during a sequential 3-phase fault on a salient pole machine operating initially on leading power factor loads.     

Smooth approximation and forecasting of load duration curves

The purpose of this paper is to develop a methodology for forecasting a load duration curve. The approach adopted in the development is to estimate a load duration curve as a combined linear-exponential function and relate the coefficients of this function to a set of economic and weather related variables. This relationship allows one to forecast the coefficients which are in turn used to provide a forecast of the coefficients of interest.The model presented, for a specific set of data, forecasts well and presents a substantial improvement over existing approaches to obtaining future load duration curves.     

A binary spelling interface with random errors.

An algorithm for design of a spelling interface based on a modified Huffman's algorithm is presented. This algorithm builds a full binary tree that allows to maximize an average probability to reach a leaf where a required character is located when a choice at each node is made with possible errors. A means to correct errors (a delete-function) and an optimization method to build this delete-function into the binary tree are also discussed. Such a spelling interface could be successfully applied to any menu-orientated alternative communication system when a user (typically, a patient with devastating neuromuscular handicap) is not able to express an intended single binary response, either through motor responses or by using of brain-computer interfaces, with an absolute reliability.     

Robust decentralized PID-based power system stabilizer design using an ILMI approach

Thanks to its essential functionality and structure simplicity, proportional-integral-derivative (PID) controllers are commonly used by industrial utilities. A robust PID-based power system stabilizer (PSS) is proposed to properly function over a wide range of operating conditions. Uncertainties in plant parameters, due to variation in generation and load patterns, are expressed in the form of a polytopic model. The PID control problem is firstly reduced to a generalized static output feedback (SOF) synthesis. The derivative action is designed and implemented as a high-pass filter based on a low-pass block to reduce its sensitivity to sensor noise. The proposed design algorithm adopts a quadratic Lyapunov approach to guarantee α-decay rate for the entire polytope. A constrained structure of Lyapunov function and SOF gain matrix is considered to enforce a decentralized scheme. Setting of controller parameters is carried out via an iterative linear matrix inequality (ILMI). Simulation results, based on a benchmark model of a two-area four-machine test system, are presented to compare the proposed design to a well-tuned conventional PSS and to the standard IEEE-PSS4B stabilizer.     

Steep front impulse flashover tests on a solid-state relay

A protective relay system, subjected to a high-voltage, steep-front impulse, has been shown to fail in the laboratory via flashover-induced current follow through on the DC power supply. Laboratory experiments were performed to characterize the response of a protective relay to steep-front impulses. These impulses may be the result of a nuclear-induced, high-altitude electromagnetic pulse. Tests were also conducted to quantify the protection offered by a surge protection package on the DC circuits of a relay system. Results from these tests were used to assess the vulnerability of a protective relay     

CMAC与卡尔曼滤波复合控制AVR的优化研究

电力系统的动态稳定已成为现代电力系统工程中一个关键性问题。同步发电机自动电压调节器(Automatic Voltage Regular, AVR)对于电力系统的稳定发挥着重要作用。为使AVR系统适应更加复杂的工作环境,增强AVR抵抗外界随机干扰和快速跟随输入信号的能力,提出了小脑模型神经网络、积分分离式 (Proportional Integral Differential, PID)控制器和卡尔曼滤波器复合控制的策略。通过对云南某水电厂的一台发电机AVR模型的仿真研究可知:该控制策略对于方波输入信号有很强的跟随能力,系统响应速度快,调节时间短,并且对控制通道和测量通道的干扰有很强的抑制作用。仿真结果充分验证了该控制策略的可行性,有助于电力系统的稳定。     

基于Camera Link的线阵CCD外同步控制设计与实现

在纺织布匹疵点检测系统中,获取平稳清晰图像对后续布匹图像疵点的精确检测和类别正确识别至关重要。由于布匹疵点检测系统外部事件的不可预测性,如何控制线阵CCD以获取平稳清晰的图像。针对这一问题提出了一种线阵CCD相机外同步控制方法。该方法采用VHDL语言在Xilinx公司Virtex-II PRO FPGA架构上设计实现。重点介绍了相机自适应的外同步控制设计方案和实现方法,通过ModelSim仿真和布匹疵点检测系统的在线测试,验证了该方法的有效性和可行性。     

A standard model of the placement problem aimed at resolving acutting stock problem

To deal with a class of problems in which dimensions of objects to be cut are unknown beforehand, a cutting optimization technique is proposed. This solution has been applied to the wood industry. It is based on a two-level hierarchical structure consisting of a placement algorithm assigned to a given plank to optimize the cutting and a process control procedure permitting production of a requested list of pieces that is the best on a limited horizon. The placement algorithm is modeled in order to formalize the control strategy. In particular, a method for connecting a system of discrete events to the more classical theory of continuous samples systems is proposed, and under the given hypothesis, an optimal control policy is established