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HA788(Ⅲ)P/TSD型电话机故障检修黎启江HA788(Ⅲ)P/TSD电话机电路图如附图所示。1)铃声小、其它正常先把铃声大小开关SWI拨到“HI”位,看铃声是否变大。若无变化,应检查R10是否变质,D1~D4中是否有损坏。若R10、D1~D4正... 相似文献
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介绍了一种有广泛应用前景的并联反馈型介质稳频振荡器(DRO)的电路原理和结构[7]。它采用平行线耦合结构,将相位调整和耦合大小的调整完全分开,易于实现和调整,从工程上基本解决了β值的选取和实现,因此提高了成品率。用此电路设计了工作频率为8.6GHZ的并联反馈型DRO,其实验结果:在偏离载频10kHZ处,相位噪声为-84dBc/Hz。 相似文献
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介绍了一种电流型10位D/A转换器的设计。着重阐述了差分式电流开关,R-2R梯形电阻、二进制电流加权网络和精密基准源的设计原理和结构。该D/A转换器采用线性兼容I2L工艺制作,具有体积小、功耗低、可靠性高、使用方便灵活等特点。线性误差、微分线性误差均低于1/2LSB,建立时间≤200ns,在-15V电源下功耗低于60mV。 相似文献
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中兴通讯自主开发了具备产业化能力的高端路由器———中兴ZXR10 -TSR电信级高端路由器。中兴通讯全系列的电信级高端路由器产品包括ZXR10 -T1000、ZXR10 -T128、ZXR10 -T64、ZXR10 -T32等 ,可满足不同的网络应用需求。其中T32是基本系统 ,T64和T128是主流系统 ,而T1000是面向未来网络业务发展的系统。ZXR10 -TSR采用先进的模块化结构和统一的系统软件平台 ,在交换容量、端口速率、端口密度及包转发能力等方面都处于国内领先的地位。该系列产品在系统的分布式处理能力、… 相似文献
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将纠随机错误和突发错误的RS码应用于HDTV信道传输中,以RS码结合交错码来提高信道传输体制的纠错能力,提出了RS码的编码方案,译码方案及交错方案。从计算机模拟的结果可以看出:采用RS码可使信道传输的误码率从10^-5降至10^-8。若将RS码一TCM码级联,可进一步提高整个系统的编码增益,使得编码增益比无编码前增加3db-5db。 相似文献
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本文介绍了一种单片12位逐次逼近型A/D转换器。它能在小于6μs的转换时间内净0-10V或-5-5V输入的范围的模拟电压转换成相对应的12位数字输出在码。电路采用p-n结隔离标准3μm双极工艺制作,在-45-+85℃温度范围,电路的线性误差和微分线性误差皆小于0.012%FSR。 相似文献
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Yasuo Nagazumi 《Analog Integrated Circuits and Signal Processing》1996,11(2):173-181
In this article, a new multiplication type D/A conversion system using CCD is proposed and the result of simulations for evaluating its performance is reported. The system consists of a recursive charge divider which divides input charge-packet Qin sequentially into output charge-packets Qin · 2-i
and two charge-packet accumulators which accumulates output charge-packets from the recursive divider selectively according to digital input signal bits starting from MSB. The system converts input digital signal bit by bit, fully in charge-domain, thus the power consumption for this system is supposed to be very low. Also in this article, an effective method to achieve higher accuracy for splitting a charge-packet into two equal-sized packets using very simple hard-ware structure is proposed. As the result of simulations, we have found that the upper limit of accuracy for the conversion is determined by transfer efficiency of CCD, and within this range a trade-off relationship exists among conversion-accuracy, circuit-size and conversion-rate. This unique relationship enables to reduce the circuit size of D/A converter significantly maintaining the accuracy of conversion by slowing down the conversion-rate. This D/A converter is appropriate especially for the system integration because of its simple structure, tolerance to the fabrication error and low power consumption inherrent in the nature of CCD. By using of this system, it is expected to be possible to realize a focal plane image processor performing parallel analog operations such as DCT conversion with CCD imager incorporated on the same Si chip by the same MOS process technology. 相似文献
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刘琪 《智能计算机与应用》2013,(6):85-87
在能够自动识别视频中的说话者的系统中,大部分采用的是声音和唇部运动相结合的方法。文中则采用了另一种方法有效地达到了目的,即通过检测人体头部和手部的运动来鉴别说话者。基于演讲者在说话时通常会伴有头部运动或是手部运动,该方法既能实现说话者的检测,又能避免由于观测点过远而导致无法判断人唇部运动的局限性。在系统的实施过程中,运用了多种图像处理方法,并且对三帧差运动法做出了改善,使其能更高效、更准确地检测到头部和手部的运动。经过多个不同的视频测试后,本系统的F1 score高达91.91%,从而验证了该系统的可行性。 相似文献
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一种新的多值A/D转换器 总被引:5,自引:0,他引:5
通过对三值 A/ D转换数学表示的分析 ,设计了二种三值 A/ D转换器电路。该转换器电路具有结构简单、低功耗、小型化和高信息密度等优点 ,它可进一步完善多值数字系统的研究 相似文献
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针对传统发动机使用的化油器反应滞后、控制不精确、排放污染大的问题,以某款单缸化油器式汽油发动机为研究对象,设计了基于MC9S12XS128单片机的电子控制系统。文中分析了单片机对A/D转化信号的采集要求,设计了各个传感器的信号处理电路及驱动电路。通过对发动机工作过程的分析,对整个控制程序进行了模块化设计,并对主要模块的控制算法进行了阐述。实验结果表明,该系统使得发动机的动力性得到了提高,最大功率约提高了6.62%,同时提高了经济性,燃油消耗量(每小时油耗)降低了5.26%,验证了电控系统的有效性。 相似文献
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《Solid-State Circuits, IEEE Journal of》1977,12(6):662-673
The quest for a minimum-parts-count DPM led to the development of this monolithic, low power analog-to-digital converter. It incorporates the analog and digital functions historically implemented separately with specialized process technologies into a chip with full /spl plusmn/3 digit accuracy. The integration of resistors, compensation capacitors, and an oscillator reduces the external component complement to three capacitors and one adjustable reference. TTL compatible outputs include sign, overrange, and under range information in addition to the three digit strobes and the BCD data outputs. The logic operates between +5 V and ground, the linear section between +5 V and -5 V. The paper describes the conversion algorithm and its CMOS implementation, emphasizing the analog design of this innovative device. 相似文献
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It is often necessary to approximate the probability density function of a random variable from given statistical moments. The Gram-Charlier Type A series is one well known method for such representations. In this note, the Gram-Charlier Type A series is generalized to the multidimensional case. 相似文献