Contactless charging of mobile devices is more convenient than fiddling around with power adapters, plugs and cables but the transmit and receive coils need to be in close physical contact otherwise power transfer losses become significant. A team of researchers in Duke’s Pratt School of Engineering working with the Toyota Research Institute of North America have succeeded in creating an array of hollow cubes which act as a lens for low-frequency magnetic fields.
The lens is made up of cells with copper coils etched onto their walls. The geometry of these coils and their repeating nature form a metamaterial that interacts with magnetic fields in such a way that the transmitted fields become confined into a narrow cone where the power intensity is much higher than that of an unfocussed pattern.
A Lens for Magnetic Fields - [Link]
A big advantage is, that practically the whole RadiCal series is also available with top-level EC motors, which are in principle motors with permanent magnets with very low power consumption (up to 50% savings).
High quality material of blades and impeller is highly resistant to ageing and corrosion ( for example also to a salt water) and it´s UV resistant. The RadiCal series contains wide range of sizes from 133 to 630 mm. At sizes over 250mm there are even available types with possibility of control via RS485 – MODBUS RTU. Majority of types is available in a basic version, intended for insertion into a suitable holder/ housing or also with an integrated holder – support basket.
What does the RadiCal series brings briefly?:
- high efficiency
- extremely quiet running with optimized air flow
- substantially decreased rotation noise
- unmatched compactness
- robust design and maintenance-free operation
- meets ErP specifications
In respect to a reliable, quiet and energy efficient operation, fans of the RadiCal series are suitable for a wide range of appliances like cooling of electronics, computers and servers, HVAC, heat recovery systems, etc.
In our standard stock offer can be found a few types of RadiCal series (for example R2E190 and R2E220) and upon order we´re able to deliver you any type from the EBM Papst portfolio. Detailed information will provide you the RadiCal centrifugal fans catalogue (49 MB).
Do you need a radical solution of ventilation or cooling? - [Link]
Dave takes a look at two cheap USB microscopes to see how suitable they are for electronics works and soldering and inspection.
EEVblog #566 – Cheap USB Microscope Reviews - [Link]
Greeeg at the 430h forum has been working on a RGB LED ring clock:
The clock is comprised of 2 rings of 60 LEDs each. the LEDs are WS2812 parts, which include a built-in driver. The PCB is one of the interesting parts of this clock. I designed the board in altium as a single 6 LED segment. and then left pads at each end to allow them to be soldered onto another segment. Currently I am using a MSP-EXP430FR5739 board to drive it, using some very in-efficient assembly code that requires a 20MHz clock.
RGB LED ring clock - [Link]
Microchip’s ENC28J60 is a 28-pin, 10BASE-T stand alone Ethernet Controller with on board MAC & PHY, 8 Kbytes of Buffer RAM and an SPI serial interface.
It takes just few components to get the ENC28J60 up and running and connected to a host microprocessor or microcontroller which support the standard SPI interface. Below I have designed a small ENC28J60 module. The ENC28J60 has a operating voltageof 3.3V, but the board is designed to run with 5V supply voltage, i.e. inculdes a 3.3 voltage regulator for the power supply and a 74ACT125 used as level shifter for the control lines. So it can be directly connected to any 5V microcontroller system. Optionally, an I2C EEPROM can be assembled on the board which can be used e.g. to store websites if the board is used in an embedded webserver environment.
ENC28J60 Ethernet Module - [Link]
Ever wondered how they transmit your TV signal?
David Kilpatrick from TXAustralia takes us on a detailed tour of the old decommissioned 10kW analog TV transmission system at the Artarmon facility in Sydney. It is still used to transmit digital TV. How it all works from the broadcaster video input to final transmission output up the 180m broadcast antenna. Plus some teardowns of the old equipment that’s been used to transmit the Channel 7 TV signal in Sydney since 1981.
Copper rigid coaxial lines, waveguides, filters, splitters, combiners, converters, transmission valve, power supplies and all the equipment necessary to transmit a 10kW analog or digital TV signal in a major city like Sydney.
EEVblog #569 – Tour of an Analog TV Transmission Facility - [Link]
The highest communication speed UMTS/HSPA+ and an easy communication via USB make the new module ideal for M2M applications.
Fast data transmission is becoming an inseparable part of devices for automotive industry, measuring, tracking, security systems, wireless terminals (POS), mobile computers etc.
When we´re choosing a module for above mentioned segments, it´s surely worth if the module also offers somewhat so to say “extra”. In case of the UC20 module it´s true, because there´s probably no parameter, which would the UC20 not meet and when you look closer at the datasheet, you´ll also find another functions like for example 2x 15 bit AD converter and other. A big advantage of the UC20 is, that it supports a fast transmission even outside of the 3G networks thanks to a dual mode (+ Multi-band) for WCDMA but even GSM with a support of GPRS/EDGE Multi-slot Class 12. A considerable benefit are also the Windows USB drivers (Linux and Android drivers are in development).
UC20 can air itself even with a high sensitivity and a high integrity of transferred data even in adverse conditions. For a development support, there are also available reference examples – UC20-reference design as well as UC20-Compatibility design regarding HW compatibility of UC20 with the M10 module.
All package (12x pdf) of software user guides can be downloaded on this link (11MB). Detailed information will provide you the documents UC20-Specification, UC20-Presentation and UC20 Hardware design.
Quectel 3G modules of UC20 series will ensure a fast transmission even on 900 MHz - [Link]
By understanding the manufacturing process you will be able design PCBs that can made more easily and cheaply. Designing boards that fit within industry standard specifications gives you two advantages: you keep down the cost of your end product, so that it will sell better; and you improve its long-term reliability, so that your customers will keep on coming back to you. And when you want to push the boundaries of technology (and who doesn’t?) you can sit down with your chosen board manufacturer and discuss your requirements knowing where he is coming from.
Eurocircuits – how to make a 4-layer PCB (full version) - [Link]
Nick Leijenhorst build a 555 PWM circuit to dim his room LED lighting. He writes:
I wanted to dim my room LED lighting with a potentiometer, and decided on creating a solution from scratch to make it more fun and educative. I decided to go with the fairly well-known 555 PWM circuit. To decrease size and for learning purposes I decided on using surface-mount components for the first time. The reason I wanted to make this 555 PWM circuit is actually just to see if I could solder SMD components on home-etched PCB’s, and to see how hard it actually is.
Surface-mount 555 PWM circuit - [Link]
The weak link in electric vehicle technology is the method of energy storage and renewal, making the vehicles impractical for long distance use. The majority of today’s electric vehicles use rechargeable lithium-ion batteries which still have a relatively poor energy density compared to conventional fossil fuels and require lengthy recharge cycles. A promising alternative battery chemistry is the lithium-sulfur battery. It can store as much as four times more energy per mass than lithium-ion batteries.
Unfortunately reactions at the battery’s sulfur-containing cathode form molecules called polysulfides that dissolve into the battery’s electrolyte. The dissolved sulfur eventually develops into a thin film called a solid-state electrolyte interface layer which coats the lithium-containing anode making the battery unusable after only 100 charge/discharge cycles.
Researchers at the US Department of Energy’s Pacific Northwest National Laboratory have succeeded in quadrupling the useful number of charge/discharge cycles. They have developed a graphite shield which moves the sulfur side reactions away from the anode’s lithium surface, preventing it from growing the debilitating interference layer. The new hybrid anode combines graphite from lithium-ion batteries with lithium from conventional lithium-sulfur batteries.
Graphite Boosts Battery Life - [Link]