浅析链路无关HID驱动程序

HID协议规范是专为USB人机交互设备开发的。本文通过对Android系统内核USB HID协议及Android内核I/O子系统的分析,探讨一种传输链路无关的处理HID设备与主机通信的内核模块的开发。将HID相关的东西从各种通信技术中隔离出来后,可以轻易的实现主机与各种不同通信链路(串口,红外等)的HID设备的连接,而不用关心HID设备与操作系统内核的交互。     

基于数字机顶盒的嵌入式USB主机接口设计

研究了怎样在多媒体数字机顶盒系统中,利用USB主机控制器芯片SL811HS实现USB1.1的主机接口,以便支持USB移动存储设备(如U盘),并在其基础上探讨了其它的扩展应用(如HID类设备).     

基于C8051f340单片机的USB HID类设备设计

USB作为近年来计算机和嵌入式领域中的热点,推动了计算机外设的飞速发展,各种具有USB接口的嵌入式系统不断涌现。但是,USB协议复杂,若为每种设备都开发相应的设备驱动程序,开发周期势必加长。介绍一种USB外设的实现方案,该方案采用C8051F340单片机内置的USB接口,实现了基于HID类协议的USB设备的设计。采用该方案实现USB设备,无需专门开发设备驱动程序。该方案实用性强,可大大缩短开发周期。     

基于USB接口的称重装置

USB是应用在PC领域的新型接口技术,与传统接口相比有着无可比拟的优越性。综合了USB传输的优越性以及HID类的特点,提出一种基于HID类的简便易行的数据采集装置的方案,使用AN2131和ICL7135,构架了一款高精度,与电脑相连接的具有数据记忆功能的称重器。该设备的设计工作包括硬件电路、USB芯片固件和主机应用程序设计3个部分。     

MSP430系统与PC机通信的USB接口设计

针对现行的USB计算机接口十分流行,广泛应用于设备与计算机的串行通信的现实性特点,考虑到USB通信其接口模块的通用性和可移植性问题,为减轻开发USB设备周期的压力,基于PDIUSBD12,设计了一个与MSP430单片机通信的USB固件接口,和与PC机相连接的应用程序的接口方案。实验结果表明,该方案能够在一定要求下稳定可靠地实现设备与主机之间的USB通信,其提供的接口程序可以简便可靠地移植到相关系统。     

基于AT89C5131的接口设计

介绍计算机与设备、设备与其他模块问的通信.采用带有USB微控制器单片机芯片AT89C5131为通信的控制核心.AT89C5131是Atmel公司推出的芯片,有较快的处理速度和较大的存储容量,还可以在系统编程,是USB接口设计的理想选择.合理设计其外围电路并用Keil Uvision 3开发固件程序,主要针对USB接口、SPI接口和键盘接口的设计与程序开发.实现计算机和设备控制面板对设备的双重控制,以及计算机通过AT89C5131使用SPI等通信协议与其他设备模块的通信.这里将USB接口通信的输入与输出通道分割开来,提高了通信速度.     

基于S3C2440的USB HID类通信接口的设计

USB设备及其驱动程序的复杂性给开发人员带来了很大的开发难度.本文给出一种以ARM9微处理器S3C2440为核心的USB HID类通信接口的设计方案.首先介绍了HID类的基础知识;然后结合主机在枚举期间的请求,论述了USB HID固件程序的实现过程;最后介绍了如何编写应用程序对HID类设备进行访问.采用该方案实现USB...     

一种实现RS232接口一对多通信的方法

RS232是一种应用广泛的串行通信接口,但传统的RS232只允许一对一通信,这种通信方式在复杂的设备中经常不能满足使用要求。针对此问题,提出一种实现RS232接口一对多通信的方法,并论述了详细的硬件和软件设计方案。该方法经过不断改进,成功地解决了通过密闭设备的一个物理接口与设备内多个RS232接口通信的难题,并在工程中得到了实际应用,拓宽了RS232的应用范围。     

IR-UWB通信系统高速USB接口的设计与实现

采用高速USB接口连接计算机终端与UWB通信系统基带模块,设计并实现了USB接口电路,控制UWB通信系统基带模块与USB接口设备的数据传输,最终实现了终端电脑与UWB通信系统的数据传输。实际测试中,USB接口的速率约为300MB/s,达到了USB2.0规范所规定的高速传输的要求。     

基于USB接口的激光无线通信系统

提出了一种以激光为载体通过计算机USB接口的通讯系统方案。该方案将计算机通过USB接口连接无线激光通信设备,实现高速的无线传输;介绍了USB的接口和协议的特点,无线光通信设备的原理,重点介绍了连接计算机和光通信设备的USB接口电路的实现方法。     

A Novel Constant Power Control Circuit for HID Electronic Ballast

This paper presents a constant power control circuit for a three-stage high-intensity discharge (HID) electronic ballast. The three-stage electronic ballast is composed of a boost pre-regulator to achieve a high power factor, a DC/DC buck converter to regulate lamp current with constant lamp power, and a full-bridge inverter to drive the HID lamp with a low-frequency ac squarewave current. The buck converter operating in current mode utilizes current sense level-shift technique to achieve constant power output. The proposed constant power control circuit is easily designed and implemented for the three-stage HID electronic ballast. Finally, a laboratory prototype of a 70 W HID electronic ballast is implemented. The measured results show that the proposed ballast can be applied for various HID lamps with low lamp power variation (less than 0.6%).     

网络热点信息发现研究

为了有效挖掘海量网络数据中的热点信息，设计了网络热点信息发现算法。基于多级滤噪进行切分词拼接，利用特定的噪声库与多级滤噪策略严格控制拼接过程，挑选合理的收录策略，提取出能够准确反映海量网络数据中热门事件的热点信息串。在TDT国际标准评测语料上算法表现出令人满意的性能。     

Genetic algorithm optimised high-intensity-discharge lamp model

Based on the physical laws of plasma arc discharge, a simple and user-friendly high-intensity-discharge (HID) lamp model optimised by genetic algorithms has been developed. The proposed model can predict lamp terminal characteristics accurately for both low and high frequency operation. All model parameters can be obtained from simple terminal measurements of the HID lamps without manufacturers' confidential data. The proposed model provides a powerful tool for simulating the electrical behaviour of the HID lamps     

数模双环路HID安定器的设计

HID氙气灯必须工作在恒定功率条件下,通常采用功率误差检测环路来实现。在分析了35 W车用HID氙气灯工作特性和市场上HID氙气灯安定器设计特点的基础上,提出了一种新颖的HID安定器的设计方案,其特点是同时采用了数字和模拟两个功率误差检测环路。实验表明,采用以此结构设计的安定器既保证了很好的瞬态特性,又保证了进入稳态后输出功率的稳定性。     

Acoustic-resonance-free electronic ballast for automotive HID lamps

A novel cost-effective and acoustic-resonance-free electronic ballast used to drive automotive high intensity discharging (HID) lamps that utilise a constant lamp power control scheme is proposed. The presented ballast is comprised of a buck-boost flyback converter to provide negative DC voltages and a half-bridge-type inverter to supply the lamp with low-frequency, square-wave AC voltage/ current. Owing to its low-frequency operation, no acoustic resonance occurs on the automotive HID lamps. Design guidelines and experimental results are demonstrated for a 35 Wautomotive HID lamp prototype ballast operating at 400 Hz switching frequency with battery input DC voltage of 12 V.     

合康变频HID620系列起重专用变频器在起重机的应用

本文介绍了合康变频H I D620变频器在起重机上的应用,使用H I D620变频器后,有效保证了起重机安全、稳定地运行,系统生产效率得到了极大提高,同时方便操作,易于维护,为客户节约了运行成本,提高了工作效率,值得广泛推广和使用。     

Novel Automotive High Intensity Discharge(HID) Lamps with Electronic Ballasts

A new scheme of automotive high intensity discharge(HID) lamps with electronic ballasts is proposed. The design of the proposed ballast and some experimental results are presented. The proposed scheme is consisted of the high frequency DC-DC converter and the low frequency DC-AC inverter. This system separates the input voltage of the ignitor from DC link voltage using auxiliary winding, then it could use the lower voltage rating power devices for HID lamp ballast system and reduce the size of HID lamp ballast. The proposed ballast controller using micro-controller unit(MCU) controls the frequency to operate the DC-DC converter in critical conduction mode, which reduces the noise of the circuit and improves the efficiency by 2%~4%.     

Design and analysis of automotive high intensity discharge lamp ballast using micro controller unit

A new scheme of the automotive high intensity discharge (HID) lamp ballast systems is proposed. The proposed scheme is consisted of the high frequency DC-DC converter and the low frequency DC-AC inverter as same as conventional HID ballast system. However this system separates the input voltage of the ignitor from DC link voltage using auxiliary winding, which results in the use of the lower voltage rating power devices for HID lamp ballast system compared with conventional system. As a result, proposed system has a lower cost or a higher efficiency. For the improvement of the efficiency, the proposed ballast controller using micro-controller unit (MCU), controls the frequency to operate the DC-DC converter in critical conduction mode. This paper presents the design and analysis of the proposed ballast and some experimental results.     

Implementation of a Voltage Multiplier Integrated HID Ballast Circuit With Dimming Control for Automotive Application

High-intensity discharge (HID) lamps are becoming popular substitutes for halogen lamps in automotive headlamps because of the high lumen/watt ratio and the color of the light. In this paper, a ballast (integrated with a voltage multiplier circuit in the secondary winding of the dc converter transformer) with dimming control is presented. The proposed circuit not only eliminates one auxiliary winding but also reduces the voltage across the switch on the primary side and consequently permits the selection of switches with a lower rating. A brief review of the HID circuits is done and compared with the proposed circuit. Experimental results from the prototype are presented. This paper also presents different methods of dimming the automotive HID lamps based on analog and digital control and discusses the relative merits of each of the methods. The dimming control is implemented using both the methods, and experimental results are presented. It is envisaged that the dimming control will provide some flexibility to drivers in the control of HID lamps to suit the driving conditions in the modern cities that are very well lit at night. This paper investigates the merits of each method and discusses the practical issues for implementing such controls.