Papers by Keyword: PCB

Abstract: The article describes impacts of incinerating PET bottles and HDPE, LDPE bags in heat sources intended for combustion of solid fuels on emission load of environment. As primary fuel was intended brown coal and municipal waste was admixed in various amounts. The article describes the process of measuring and evaluating emissions during their incineration.

Abstract: Due to the weak rigidity of micro-drills and impulse effects, the micro-drill breakage is a common problem in printed circuit board micro-drilling. Traditional micro-drill breakage detection methods and principles, including vacuum-type, laser-type, and contact-type detection, were reviewed in this paper. The comparison of three detection methods showed that the contact-type detection can more satisfy the performance of CNC drilling machine. Three effective contact-detection circuits, including no transformer and rectifier circuit pulse-type, active-type, and trigger-type detection circuit, were introduced. And as a conclusion, differences of these detection methods were compared. Based on the characteristic of three effective micro-drill breakage contact detection circuits, the development trends and designs of innovative detection circuit were proposed to meet the challenges in micro-drill breakage measurement during PCB drilling.

Abstract: With the development of digital signal processing technology, the demand on the signal processor speed has become increasingly high. This paper describes the hardware design of carrier board in high-speed signal processing module, which using Xilinx's newest Virtex-7 FPGA family XC7VX485T chip, and applying high-speed signal processing interface FMC to transport and communicate high-speed data between carrier board and daughter card with high-speed ADC and DAC. This design provides a hardware implementation and algorithm verification platform for high-speed digital signal processing system.

Abstract: Defective products are unavoidable in printed circuit board production process, so rapid detection and identificationmethods are badly in need of. PCB surface defect detection including a series of processing such as surface imagecapture, mixed noise filtering,images registering and so on, so it takes a lot of CPU time. To improve detection speed, based on GPU parallel computing platform, we designed a reasonable parallel processing system for PCB defect detectionto meet the need of real-time requirements of a production line. Experimental results show that parallel image processing algorithms based on GPU can achieve good results compared to the CPU-based serial algorithm (with speed up ratio up to8.34 in this paper),providing a new approachfor rapid detection of PCB surface defect.

Abstract: The minimum CPU system of TMS320VC54x DSP does not have redundant extended peripherals, it can work independently, perform real-time online simulation and burn program code. The paper mainly introduces the system design idea, the key points of design and matters needing attention, the paper offers the hardware circuit principle diagram of each unit of the minimum CPU system of TM320VC54x and the PCB diagram. The paper can work as the reference for the design of the minimum system of other CPU.

Abstract: This article presents a method for testing and identification of a recovery material of certain missile, systematically analyzes the diagnostic approach and technology of PCB faults, expounds in detail design concept of the system, sets forth the solution using C8051F020 chip as microprocessor and testing of analog and digital I/O with built-in converter, contrives polarity discrimination circuit, provides software design process and main program by means of design thinking of modularized software, which help increasing program reliability and lowering development cost. The experimentation proves that this system is able to precisely position the faulty module of PCB to be identified, as well as make correct and reasonable opinion for maintenance. The design method and concept of this article is of significant value for reference in the research and development of similar testing and identification system.

Abstract: PCBs removal in the aged leachate by a new combination process based on an innovative biofilm reactor with natural fiber media, combined coagulation with a two-staged sequencing batch biofilm reactor with Luffa Sponges (LS) as the biomass carriers (LS-SBBR), was studied in this paper. The results indicated that the total PCBs removal in the aged leachate was 51.97%, and the PCBs removals are mainly achieved by the removal of trichlorobiphenyls, the PCBs contents in sludge in the two-staged LS-SBBR were consistent with the conclusion that the PCBs removal in liquid phase of the second LS-SBBR was higher than that of the first LS-SBBR.

Abstract: Electronic current transformers are more suitable for the development of power system compared with traditional electromagnetic current transformers. Rogowski coil current transformer is one of three electric current transformers. According to the measurement principle of Rogowski coils, the equivalent circuit of PCB Rogowski coils is analyzed. By using four PCB Rogowski coils combined, a PCB Rogowski coil current transformer is designed and tested. The results show that the designed PCB Rogowski coil transformer has good linearity and high sensitivity and measurement accuracy and it can meet the requirement of power system.

Abstract: Components soldered with Sn-based alloys are susceptible to the growth of whiskers. Tin whiskers have been proven to be responsible for equipment failures in a wide range of industries. In order to reduce defects in electronic components a new solder alloy is proposed based on the Sn-Cu alloys. The Sn-Cu-Ga alloy utilised in this study was fabricated as a ribbons using melt-spinning method. These ribbons were then soldered onto electroplated tin layers. Preliminary characterization of the solder alloy is presented in this paper, including scanning electron microscopy, EDX mapping and X-ray diffraction. Key words: tin whiskers, PCB, printed circuit boards, melt spinning, solder, ribbons

Abstract: With the development and exhaustion of resources, the reclamation of secondary resources, especially urban mine, must be on the agenda. The major part of urban mine is waste printed circuit board (WPCB), and the effective processing of WPCB is depend on the disassembly. This article analyze the form of fastening, the method of fusion welding ,the recovery of welding and the disassembly of electronic component in process of disassembly, and point out the direction and tendency of development.