梳齿分布结构对静电驱动二维微扫描镜机械转角的影响

为增大静电驱动二维微扫描镜的机械转角,基于非线性动力学理论研究了不同梳齿结构对其振幅的影响,理论上得到发散型梳齿分布相较于平行型梳齿分布具有更大的机械转角。此外,采用绝缘体上硅(SOI)加工工艺设计并制作了这两种结构的微扫描镜,并对其相关特性进行了测试。测试结果表明:在相同的驱动电压下,发散型结构始终都比平行型结构具有更大的机械转角,与仿真结果基本一致;当加载驱动电压为42 V的方波信号时,发散型结构扫描镜的可动框架和镜面的最大机械转角可以达到12.3°、13.49°,而平行型结构扫描镜的可动框架和镜面的最大机械转角则为10.25°、11.68°。     

直流电机的IR2110驱动控制设计及DSP实现

为了解决直流电机转向及速度控制问题,设计了一种H桥驱动电路。以IRF530为开关元件、IR2110为栅极驱动芯片,由DSP产生PWM信号,经过光耦隔离和逻辑电路后送至IR2110进行控制。给出了整体驱动控制电路、上下桥臂的栅源电压波形、上桥臂的浮动电压信号以及电机两端的运行电压信号。测试分析表明,该方案很好地实现了电机的正反转控制及电机速度调节,电机运行平稳,达到了设计要求,对直流电机控制应用具有较高的参考价值。     

抑制电子管灯丝电路产生交流声的措施

在电子管放大器中灯丝电路是产生交流声的主要来源。直热式阴极的电子管采用交流供电时,由于栅、阴之间有灯丝电压的电位差,使屏流随着灯丝电压而波动,形成交流声。其次灯丝的温度随灯丝电流大小而改变,灯丝虽有热惰性,也不可能绝对保持发射的电流大小不变,由于交流一个周期内有两个最大值,所以其引起的交流声频率是交流电源频率的2倍。旁热式阴极电子管,因上述原因引起的交流声要小得多。但因灯丝和阴极及栅极间有漏电阻和分布电容(它们是由包括电子管内部的电极之间和外部的管座及元件布线之间所形成)。于是灯丝电压将使灯丝和阴极以及栅极电路产生漏电流。因栅极电阻数值一般很大,那怕是微小的电流波动所造成的电压降波动也是不可忽视的,尤其是前极电子管受到交流的微小干扰,经过整     

基于平衡PZT法解调的FBG传感器

提出了一种基于压电陶瓷叠堆驱动参考光纤Bragg光栅(FBG)扫描滤波的FBG传感器波长解调机构,设计了对称结构U型金属支架结构,并采用两侧粘贴光纤光栅的方式,同时对光纤光栅施加相等的预应力,这种结构扩展了解调光栅的扫描范围,平衡了压电陶瓷叠堆所受的拉力,增强了其运行可靠性,提高了扫描线性度.实验结果显示:在0-200...     

基于MC34063的大电流负电源设计

采用MC34063设计带电流扩充的负电源电路,功率MOS管NTB2506作外接开关管,通过调节功率MOS管的栅极驱动电阻和栅一源之间的电阻,使得栅极有最优驱动电压波形和电流大小,以增加电源的输出功率和效率.实验表明,设计的电源输出电流可达1 A,且体积小、效率高.     

一种实用的缺相保护电路剖析

故障现像：黑屏但开机时有‘唰’声．指示灯为绿色．故障分析：开机时有‘唰’声说明高压正常．指示灯为绿色．说明信号输入及CPU对信号的识别正常。故障可能在显像管附属电路中．如加速极栅极、阴极电压不正常。     

GW—300显示器无光栅故障的分析与维修

GW—300显示器故障,以无光栅不显示最为常见。大家知道,显示器要显示正常的光栅,除去显象管老化及G、R、B三色平衡等因素外,还依赖于电子枪各级所加电压要正常,即灯丝供电、阴极电位、栅极各极中压及阳极高压以及行、场偏转扫描要正常。这些电压和行偏转电流全来自行输出级和行输出变压器(高压包)各绕组。行输出级工作在高频、高压、大电流状态,     

数字隔离器在工业电机驱动应用中的优势

简介工业电机驱动中使用的电子控制必须能在恶劣的电气环境中提供较高的系统性能。电源电路会在电机绕组上导致电压沿激增现象,而这些电压沿则可以电容耦合进低电压电路之中。电源电路中,电源开关和寄生元件的非理想行为也会产生感性耦合噪声。控制电路与电机和传感器之间的长电缆形成多种路径,可将噪声耦合到控制反馈信号中。高性能驱动器需要必须与高噪声电源电路隔离开的高保真反馈控制和信号。在典型的驱动系统中,包括隔离栅极驱动信号,以便将逆变器、电流和位置反馈信号驱动到电机控制器,以及隔离各子系统之间的通信信号。实现信号隔离时,不得牺牲信号路径的带宽,也不得显著增加系统成本。光耦合器是跨越隔离栅实现安全隔离的传统方法。尽管光耦合器已使用数十年,其不足也会影响系统级的性能。     

运用多相数字电源解决方案解决系统问题

通过将F2806数字信号控制器与UCD7230栅极驱动及电流传感放大器完美结合,设计了一款用于数控多相交错式DC/DC降压系统的完整信号控制解决方案,该方案具有多相同步降压转换器的优点,同时可以运用数字方法关闭电压控制环路,对不同负载和散热条件下的相位进行管理以获得最佳电源性能。     

基于TMS320F2812 FAIMS仪用RF电源控制系统

文中提出一个FAIMS仪用高场非对称方波RF电源系统设计方案,系统由信号发生器、高速开关、高压直流电源、高通滤波、补偿电压自动扫描及采集、和计算机控制六部分组成.以TMS320F2812为信号发生及控制核心,驱动高速开关通过逆变产生方波RF信号同时控制DAC转换实现补偿电压自动扫描.该电源系统可以输出频率≤2MHz.电压幅值≤2kV,功率≤300W,占空比20%～50%,波形上升时间约15ns的非对称方渡波形.     

Operating characteristics and TV image display of a grid-controlled matrix fluorescent display panel

The basic structure and the driving methods for a grid-controlled matrix fluorescent display panel are discussed Two experimental TV image display sets were made using a four-electrode display panel and a five-electrode display panel with 268 × 392 = 105 056 and 573 × 782 = 448 086 pixels respectively. The vertical scanning and driving circuits are considerably simplified by means of the anode grid decoding. One TV set has only 24 sets of anode drivers, and for the other the number of anode drivers is further reduced from 24 to one. A technique for diminishing cross-talk between the neighbouring picture elements is also discussed, and a cathode pulse driving method adopted to provide a uniform display.     

A novel TFT‐OLED integration for OLED‐independent pixel programming in amorphous‐Si AMOLED pixels

Abstract— The direct voltage programming of active‐matrix organic light‐emitting‐diode (AMOLED) pixels with n‐channel amorphous‐Si (a‐Si) TFTs requires a contact between the driving TFT and the OLED cathode. Current processing constraints only permit connecting the driving TFT to the OLED anode. Here, a new “inverted” integration technique which makes the direct programming possible by connecting the driver n‐channel a‐Si TFT to the OLED cathode is demonstrated. As a result, the pixel drive current increases by an order of magnitude for the same data voltages and the pixel data voltage for turn‐on drops by several volts. In addition, the pixel drive current becomes independent of the OLED characteristics so that OLED aging does not affect the pixel current. Furthermore, the new integration technique is modified to allow substrate rotation during OLED evaporation to improve the pixel yield and uniformity. The new integration technique is important for realizing active‐matrix OLED displays with a‐Si technology and conventional bottom‐anode OLEDs.     

PEM fuel cell low flow FDI

In this work, a signal-based diagnostic methodology that can isolate PEM fuel cell low anode and cathode flow rates is introduced. The methodology is based on calculating symptoms of the faults, and comparing them versus thresholds that are calibrated a priori of real time operation. The novelty with the methodology is in using cell voltage oscillations, imposed by a small signal oscillation on the cathode output pressure, to isolate cathode flooding. Furthermore, it is shown in this work that the fixed reference cathode stoichiometry commonly used in the literature for isolating cathode starvation is not reliable and results in false alarms, and an adaptive scheme is proposed. It is also shown that a fixed stoichiometry scheme can be used to reliably isolate anode starvation. These measures are then used to design a signal-based diagnostic algorithm to isolate cathode flooding, cathode starvation, and anode starvation in real time. Finally, the robustness of the algorithm to changes in current, pressure, temperature, and humidity operating conditions is examined.     

Practical CNT‐FED structure for high‐luminance character displays

Abstract— A high‐luminance CNT‐FED character display using a simple line rib structure was constructed. The display panel had 48 × 480 dots and the subpixel pitch was 1 mm. The greatest benefit of a display using CNT technology is high luminance performance with low‐power consumption. The luminance of the green‐color dot wasca. 10,000 cd/m² under 1/1 6 duty‐cycle driving at a 6‐kV anode voltage. The high luminance of the display panel can provide good visibility when installed even in outdoor locations, and the power consumption was ca. 4 W at the character displaying module. This, a CNT‐FED for character displays also has potential multifunctionality, which could be battery driven. It should be useful for public displays even under emergency no‐power conditions. In this work, a practical structure and process technologies for making ribs with reasonable cost were developed. The newly introduced 2‐mm‐tall line ribs as spacers were formed by using innovative production processes; i.e., the rib paste was pushed out of a multi‐slit nozzle, and the rib shape was formed by UV‐light irradiation. The developed panel structure and manufacturing processes also had the advantages of size flexibility and high production yield.     

Observation on CNT-FED under various vacuum levels and calculation on number of electron–gas collisions

Based on experimental observation and theoretical analysis, it explicates that light emission of a carbon nanotube-field emission display (CNT-FED) is mainly caused by electron bombardment on the phosphour if the level of vacuum ranges from 10⁻⁴ to 5 Pa. In this case, light emission of the phosphour excited by ultraviolet (UV) light derived from gas discharge cannot be observed. If vacuum level is greater than 5 Pa, no emitted light is observed, since a large amount of gas ionisation reduces the electric potential difference between the cathode and the anode. To analyze collision between electron and gas under field emission conditions, a mathematical and physical model was built. Based on this model the number of electron–gas collisions is calculated. Calculations results indicate that the product of gas pressure and distance between the electrodes (pd) is a better parameter to characterize the effect of vacuum level for FED than gas pressure only. Calculations results also show that if the distance between the cathode and the anode is increased, it should be to improve the vacuum level to obtain the same effect.     

Large‐screen displays using metal—insulator—metal cathode arrays

Abstract— Large‐screen (32‐in. WXGA and 17‐in. VGA) displays using metal—insulator—metal (MIM) cathode arrays have been developed. A cathode structure with low‐resistance electrodes and low‐capacitance emitters shortens signal delay and decreases the voltage drop in large MIM‐cathode arrays. By using a dual‐scan method, the signal delay was suppressed to less than 30% of the horizontal scan time in the 32‐in. WXGA panel. Emission efficiency of the cathode array was improved to 3% by reducing the surface work function of the top electrode from 4.7 to 3.9 eV. The cathode life was also improved to more than 10,000 hours. The display panel incorporating the cathode arrays and high‐efficiency P22‐phosphor screens with 3‐mm spacers showed high screen brightness (average brightness, 378 cd/m²; peak brightness, 832 cd/m²) at an anode voltage of 10 kV.     

Anode‐voltage‐control circuit for compensation of luminance deterioration

Abstract— An external driving circuit that has realized long lifetime, power‐consumption control, and peak luminance for organic light‐emitting diode (OLED) displays have been developed. This circuit realizes an effective method for constant‐anode‐voltage (CV) driving refered to as clamped inverter (CI) driving. The feature of CV driving is to achieve low‐power consumption compared with constant‐anode‐current (CC) driving and to control the power consumption and peak luminance according to the image because display luminance can be easily changed by controlling the anode voltage. On the other hand, CV driving has the problem that luminance deterioration appears to be serious compared with that of CC driving because the current of the OLED element decreases according to usage time. To cope with this, a lifetime compensation circuit that has increased the anode voltage so that it compensates for the luminance deterioration has been developed. This circuit can compensate not only the decrease in current but also the decrease in luminance at a constant current that CC driving cannot. However, increasing the anode voltage causes an increase in stress on the OLED element. The influence of stress on OLED lifetime was verified. As a result, it was confirmed that this circuit can extend the lifetime by 32% even if the anode voltage is increased, causing stress on the OLED structure.     

Multioutputs single‐stage gate driver on array with wide temperature operable thin‐film‐transistor liquid‐crystal display for high resolution application

A hydrogenated amorphous silicon (a‐Si:H) thin‐film transistor (TFT) gate driver with multioutputs (eight outputs per stage) for high reliability, 10.7‐inch automotive display has been proposed. The driver circuit is composed of one SR controller, eight driving TFTs (one stage to eight outputs) with bridging TFTs. The SR controller, which starts up the driving TFTs, could also prevent the noise of gate line for nonworking period. The bridging TFT, using width decreasing which connects between the SR controller and the driving TFT, could produce the floating state which is beneficial to couple the gate voltage, improves the driving ability of output, and reaches consistent rising time in high temperature and low temperature environment. Moreover, 8‐phase clocks with 75% overlapping and dual‐side driving scheme are also used in the circuit design to ensure enough charging time and reduce the loading of each gate line. According to lifetime test results, the proposed gate driver of 720 stages pass the extreme temperature range test (90°C and ?40°C) for simulation, and operates stably over 800 hours at 90°C for measurement. Besides, this design is successfully demonstrated in a 10.7‐inch full HD (1080 × RGB×1920) TFT‐liquid‐crystal display (LCD) panel.     

A linear multisensor for temperature and magnetic field based on diode structure

A new type linear silicon multisensor using the functional principle for simultaneous and independent measurement of temperature and magnetic field is suggested and investigated experimentally in wide temperature range 77 K≤T≤393 K. The structure is a differential microdiode with strip geometry. The temperature output signal is the anode–cathode voltage at a constant supply current, which is linear in the range 77 K≤T≤393 K, but the magnetosensitive one is a differential current between both base contacts. A strong magnetic field up to 1.5 T at T=300 K does not influence the selected thermometric signal.     

基于FPGA的TFT LCD快检信号源的设计

目前TFT模块的生产过程中常伴有模块的线缺陷和点缺陷,依据TFF模块的驱动和测试原理,设计了一种由FPGA和模拟开关组成的集成测试信号源,该信号源可提供源极信号、栅极信号、栅极控制信号和公共地信号四路测试信号,此四路信号无论是在频率、占空比、延时,还是幅值上都满足对一般中小尺寸TFT液晶模块的线缺陷和点缺陷的测试要求,可以灵活方便地移植到其他模块测试中,具有通用性.