基于DSP的喷油器电磁阀驱动电路设计

根据柴油发动机喷油电磁阀在实际工作中电磁力与电流的关系,设计出一种基于TMS320F28035DSP的柴油机电控喷油电磁阀的驱动电路,以达到提高电磁阀开启与关闭速度、降低能耗和简化电路的目的;驱动电路利用28035DSP内部集成的比较器模块和EPWM模块实现多个电磁阀的驱动,电磁阀高端采用80V高压和24V低压双电源分时驱动技术,电磁阀低端采用电流反馈PWM调制控制技术;试验结果表明:驱动电路实现了12A峰值电流和4A保持电流的电流控制,电流波形满足电磁阀驱动特性,显著提升了电磁阀开启与关闭速度,降低了系统能耗。     

柴油喷嘴驱动电路的PSPICE仿真

针对柴油/天然气掺烧电控系统设计了一种新型的喷嘴驱动电路,该驱动电路采用高低端双电源的电路结构,实现电流峰值恒流驱动方式;通过建模仿真验证喷嘴在开启阶段采用高电压驱动可以加快响应速度;为满足喷油过程中对电流下降速率的要求,优化电路结构,实现了不同阶段续流电路的自动转换;最后通过PSPICE软件和台架实验对驱动电路的正确性进行验证,结果表明该电路可以有效缩短喷嘴的开启和关断时间,实现了喷油量和喷油定时的精确控制。     

一种新型高压共轨喷油器驱动电路的设计

针对一般高压共轨电磁铁型喷油器驱动电路存在的问题,提出了一种新的驱动电路.该驱动电路具有分散功率调制结构可以平均分配各个MOS管的功率,可耐受喷油器高频驱动电流的开关损耗,提高整个驱动电路的运行可靠性.该驱动电路还可以实现维持电流峰值限制,精确调制等功能,并能够降低对地的高频干扰.     

反作用控制系统电磁阀PWM控制技术研究

针对反作用控制系统快速响应电磁阀频繁工作的特性,从节能控制的角度出发,设计了一种基于脉宽调制技术的电磁阀控制驱动方案;建立电磁阀电路模型,通过仿真计算,确定了PWM频率及占空比对电磁阀线圈电流的影响,为电磁阀驱动电路参数的选取提供依据;搭建RCS电磁阀电流测试平台.设定PWM占空比为50％,试验结果表明:流经电磁阀的保持电流仅为开启电流的1/2,既能保证电磁阀正常开启,又避免了电磁阀处于高负载工作状态,有效地验证了该节能控制方案的正确性.     

电动助力转向系统硬件设计及试验研究

电动助力转向系统(EPS)是一种通过电动机为驾驶员提供转向助力的装置.系统的控制器(ECU)通过控制PWM输出脉冲占空比的方式来决定电动机电枢两端的电压,从而控制助力电流的大小.本文给出了基于飞利浦P87C591单片机的EPS硬件电路框图,并详细介绍了功率驱动电路及逻辑控制电路.对所设计的硬件电路在试验台架上进行了各种试验,结果表明:设计的硬件电路在软件的配合下能够实现基本的控制功能.     

数字可调检测电源的设计

针对目前电子市场缺少专门对电磁阀供电的检测电源以及现有电源抗冲击电流弱的问题,设计了一种用于电磁阀检测的专用数字可调电源,以检测电磁阀长时间运行的稳定性.电源系统硬件主要由电压和频率控制电路、相关电压处理电路、频率处理电路以及综合输出电路组成;软件设计采用C51编程控制,实现了在0~36 V内连续电压可调和0~25 kHz内连续频率可调.实践表明该检测电源完全满足电磁阀感性负载可能产生大冲击电流的需求.     

特种机器人的低电压大功率电机驱动系统设计

针对核辐射应急处理机器人驱动系统体积小、驱动能力强且操控灵活的需求,基于IR2184驱动并联MOS管H桥电路,设计了一种适用于特种机器人的低电压大功率电机驱动系统.系统针对驱动中的尖峰问题设计了RCD吸收回路,并针对MOS并联中的局部过流问题设计了均流保护电路.实验表明,驱动电压为24 V时,驱动电流最大可达100 A,最终实现了对特种机器人的可靠控制.     

基于双向TVS的电磁阀加速释放电路研究

为了解决某型号姿轨控发动机关闭响应性能不满足指标的问题,对影响发动机关闭响应性能的因素及电磁阀驱动电路进行了分析,提出了增加外部释放电阻法和基于双向TVS的两种电磁阀加速释放电路。通过仿真分析与试验验证,采用基于双向TVS的电磁阀加速释放电路不仅可以提高电磁阀的关闭响应速度,减小电磁阀的关闭响应时间；还能够有效地抑制电磁阀关断时产生的反向电动势,对驱动电路具有良好的保护作用。该电路已在多个型号姿轨控发动机电磁阀驱动电路中得到应用,并参加了全系统热试车及飞行试验,取得了良好的效果。     

一种高速开关电磁阀智能驱动模块的设计

根据电磁铁的电磁吸力与线圈电流的关系,设计出一种基于PWM控制方式的高速开关电磁阀智能驱动模块.该驱动模块采用高低端驱动技术和电路反馈技术实现了电磁阀的快速驱动以及驱动故障的自诊断功能.     

电阻抗成像系统中的多频恒流源设计

设计了一种基于单片机与AD7008的应用于电阻抗成像系统中的多频恒流源,给出了恒流源的系统组成结构、硬件电路设计、程序流程图,并用PSpice软件对椭圆低通滤波器电路和V/I转换(电压转换为电流)电路进行了仿真和优化设计,实验结果表明所设计的多频恒流源满足电阻抗成像系统的要求.     

Fast voltage‐driving scheme for AMOLED displays based on internal feedback

Abstract— A new driving scheme for active‐matrix organic light‐emitting diodes (AMOLED) displays based on voltage programming is proposed. While conventional voltage drivers have a trade‐off between speed and accuracy, the new scheme is inherently fast and accurate. Based on the new driving scheme, a fast pixel circuit is designed using amorphous‐silicon (a‐Si) thin‐film transistors (TFTs). As the simulation results indicate, this pixel circuit can compensate the threshold‐voltage shift (VT shift) of the driver transistors. This pixel can be programmed in just 10 μsec, and it can compensate the threshold‐voltage shifts over 5 V with an error rate of less than 5% for a 1 ‐μA pixel current.     

一种带多重保护的高压功率放大器

针对市场上常规信号源输出电压低,带负载能力弱,无法驱动超声波换能器等大功率容性负载的实际问题,以高压运算放大器PA84为核心器件,设计了一种高压功率放大器.放大器采用单片机作为控制核心,利用单片机自带的A/D并结合自建的高速仪用放大电路,实时采样输出电流,实现了输出短路及过流保护;利用自建的调零电路实现了放大器上电自动调零,有效减小了放大器的零点漂移;高压供电回路中串接自恢复保险丝,实现了对输出功率的限制.该放大器输出幅度可达±140V,最大工作电流1A,并具有完善的过载及功率保护功能.实验结果表明,放大器具有较好的线性度和稳定性,满足工程实际需求.     

LVDT位移传感器电压电流转换电路的设计

为使传感器输出信号能够远距离传输,设计了一种0～5 V到4～20 mA的电压电流转换电路。在Howland电流泵电路的基础上,增加电压跟随器和偏置直流放大器,实现电压电流的精确转换。仿真分析和实验测试结果表明:电路能够满足传感器电流输出的要求,并已成功应用于LVDT位移传感器调理电路。     

故障诊断控制器的电路设计及精度研究

针对目前故障诊断控制器中电液伺服阀显示电路影响其驱动电路设计的问题,提出了用电流模拟表头与继电器方法,代替使用采样电路和电压模拟表头的方式,改善了线性度和精度;介绍了一种电位计和电阻结合的方法,提高了电位计在应用电路中的精度和灵活度。     

A novel gate driver circuit for depletion‐mode a‐IGZO TFTs

In this paper, a novel gate driver circuit, which can achieve high reliability for depletion mode in a‐InGaZnO thin‐film transistors (TFTs), was proposed. To prevent the leakage current paths for Q node effectively, the new driving method was proposed by adopting the negative gate‐to‐source voltage (V_GS) value for pull‐down units. The results showed all the V_OUT voltage waveforms were maintained at VGH voltage despite depletion‐mode operation. The proposed circuit could also obtain stable V_OUT voltage when the threshold voltage for all TFTs was changed from ?6.5 to +11.5 V. Therefore, the circuit can achieve high reliability regardless of threshold voltage value for a‐IGZO TFTs. In addition, the output characteristics and total power consumption were shown for the alternating current (AC)–driven and direct current (DC)–driven methods based on 120‐Hz full‐HD graphics (1920 × 1080) display panel. The results showed that the AC‐driven method could achieve improved V_OUT characteristics compared with DC‐driven method since the leakage current path for Q node can be completely eliminated. Although power consumption of the AC‐driven method can be slightly increased compared with the DC‐driven method for enhancement mode, consumption can be lower when the operation has depletion‐mode characteristics by preventing a leakage current path for pull‐down units. Consequently, the proposed gate driver circuit can overcome the problems caused by the characteristics of a‐IGZO TFTs.     

一种新型瞬变电磁仪发射电路设计

为提高瞬变电磁仪测量的准确度,设计了基于FPGA的瞬变电磁仪发射电路。该电路采用EXB841模块设计驱动电路,实现对H桥路上下臂MOSFET的有效驱动;利用改进的H桥路设计及改变传统桥路的控制策略,实现对MOSFET的超短时间关断;采用RCD吸收保护电路降低尖峰电压干扰,改善发射电路输出波形。试验结果表明,该发射电路的发射信号过压仅为正常信号的1.33倍,振荡时间为500ns,下降沿时间为700ns,实现了发射电流的快速关断,且稳定性好。     

用于煤矿电缆绝缘参数在线测量的附加低频信号源设计

分析了附加低频信号源测量电缆绝缘参数的基本原理,详细介绍了该信号源中优化的SPWM驱动电路、输入和输出保护电路和RS232通信电路的设计,其中优化的SPWM驱动电路可输出-8～+12V的电压,保证了IGBT的可靠开通和关断。实验结果表明,该信号源输出电压幅值稳定、频率连续可调。     

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.