Advanced searches left 3/3

PCB - DOAJ

Summarized by Plex Scholar
Last Updated: 08 September 2022

* If you want to update the article please login/register

Balanced-YOLOv3: Addressing the Imbalance Problem of Object Detection in PCB Assembly Scene

The object detection system of the PCB assembly scene based on CNN can significantly increase the manufacturing capacity of electronic products that are intelligently manufactured. However, object classification in the PCB assembly process, the multi-scale feature imbalance, and the positive/negative sample mismatch in the CNN have all posed significant challenges to object detection results, restricting object detection results. Balanced-YOLOv3, as opposed to other modern anchor-based object detection schemes, has high detection rate and low computational complexity, effectively solving the problem of imbalanced object detection in PCB assembly scenarios.

Source link: https://doi.org/10.3390/electronics11081183


Ratio of Mercury Concentration to PCB Concentration Varies with Sex of White Sucker (Catostomus commersonii)

In 25 mature female and 26 mature male white suckers caught during their spawning run in the Kewaunee River, a tributary to Lake Michigan, with whole-fish total mercury levels determined. Males were found to be 18% higher than females in polychlorinated biphenyl concentrations in a previous research on the same 51 white suckers from the Kewaunee River spawning run. The ratio of Hg concentration to PCB concentration in females was much higher than that in males, according to We discovered that the ratio of Hg concentration to PCB concentration in females was significantly higher than that in males. The white suckers had significantly higher Hg levels than those in fish consumption, well below federal recommendations.

Source link: https://doi.org/10.3390/environments5090094


Thermal, Photometric and Radiometric Properties of Multi-Color LEDs Situated on the Common PCB

This paper presents the findings of experimental studies demonstrating the effects of the spectra of the light produced by power LEDs on their thermometric, photometric, and radiometric properties. The method and setups for potential measurements of self and transfer transient thermal impedances, illuminance, and the surface power density of the light generated by the tested devices are described in the paper. These findings show that the spectra of the emitted light can have an effect on self-transient thermal impedances of the considered systems and transfer transient thermal impedances between two pairs of these devices.

Source link: https://doi.org/10.3390/electronics9101672


Reduced-Reflection Multilayer PCB Microstrip with Discontinuity Characterization

Printed circuit boards can be found in a multitude of applications in the age of electronics and communications, ranging from common household items to state of the art custom metrology equipment. The signal landpads for some high-frequency connectors and components, which are encapsulated in larger containers, are often wider than the controlled impedance trace, resulting in signal reflections and unnecessary impedance mismatch. This paper examines the difference between the compensated and uncompensated microstrip with discontinuity, which is larger than the intended impedance microstrip, and suggests a generalized roadmap on compensating for the introduced impedance change in multilayer PCBs. In the whole frequency bandwagon range up to 10 GHz, a dB increase in S 11 response in the whole frequency bandwagon range up to 10 GHz was reported as compared to one where no compensation has been applied.

Source link: https://doi.org/10.3390/electronics9091473


Winding Design and Analysis for a Disc-Type Permanent-Magnet Synchronous Motor with a PCB Stator

A printed circuit board is a stator board in a disc-type permanent-magnet synchronous motor. The stator's design has a direct effect on motor efficiency and the stator's utilization rate. However, a PCB stator limits the manufacture of the disc-type electric motor with a PCB stator in certain respects. The new winding has not only increased no-load back EMF, as well as output capacity and safety under load, but also the utilization rate of the stator was much improved, according to the report.

Source link: https://doi.org/10.3390/en11123383


Design Optimization of PCB-Based Rotary-Inductive Position Sensors

This paper presents a novel approach to optimize the manufacturing of a ratiometric rotary inductive position sensor made in printed circuit board technology. For this reason, the original optimization procedure in this paper reverts the RX coils' shape to simulate theoretical coil voltages as much as possible. Simulations and experiments on different prototypes of an absolute rotary sensor show the efficiency of the optimization device.

Source link: https://doi.org/10.3390/s22134683


A Review and Comparison of Solid, Multi-Strands and Litz Style PCB Winding

At high speeds, AC resistance of a printed circuit board winding becomes more important, and it accounts for a significant portion of planar transformer losses. Many researchers have focused on the study of increasing AC resistance of a PCB winding. This paper explores the benefits and drawbacks of three common AC resistance optimization techniques: increasing track width of a good PCB winding, using multi-strands, and using Litz style PCB winding to overcome the above limitations. Optimizing track width results has resulted in significant increases in AC resistance, according to the results of this research, although the use of Litz PCB is effective for applications that require stable AC resistance in a wide frequency range. Both reducing the AC resistance and DC ratio should be treated seriously, as the use of parallel strands winding should not be particularly beneficial.

Source link: https://doi.org/10.3390/electronics9081324


PCBs in Older Buildings: Measuring PCB Levels in Caulk and Window Glazing Materials in Older Buildings

A method for the detection of polychlorinated biphenyls in caulk and glazing materials was developed and tested by application to a mixture of 36 samples of caulk and glazing materials from four schools in the northeastern region of the United States' northeastern region.

Source link: https://doi.org/10.3390/environments6020015


PCB-Embedded Spiral Pattern Pick-up Coil Current Sensor for WBG Devices

The current of a power semiconductor device is mainly determined by using a Rogowski coil, an active current transformer, and a coaxial shunt resistor. Because of their operational principle, the Rogowski coil and active current transformer are not suitable for the current measurement of surface mount WBG units. Since WBG units are more sensitive to parasitic inductance than silicon ones, parasitic inductance may have a direct effect on circuit operation. This paper discusses a printed circuit board-embedded spiral pattern pick-up coil current measurement for WBG devices in order to solve these issues.

Source link: https://doi.org/10.3390/en13215747

* Please keep in mind that all text is summarized by machine, we do not bear any responsibility, and you should always check original source before taking any actions

* Please keep in mind that all text is summarized by machine, we do not bear any responsibility, and you should always check original source before taking any actions