Kerry D. Wong builds a digitally controlled power supply based on ATmega328P mcu:
In my previous post, I showed my design of a dual tracking ±30V linear power supply. My goal was to use the transformer (28V+28V, center tapped) from an old Deltron W127G open-frame power supply and build a lab supply that can be digitally adjusted in both constant voltage and constant current modes. I also wanted each of the channels to be able to deliver up to 10 Amps of current so that I could fully utilize the 540VA transfomer from the W127G.
A Digitally Controlled Dual Tracking Power Supply - [Link]
The Stanford University theoretical physicist Shoucheng Zhang and colleagues have suggested that a new material called Stanene, composed of a one-atom-thick sheet of tin, could act much like a room temperature superconductor.
Stanene is a type of topological insulator where the body of the material is an insulator but the surface and edges are electrically conductive. As electrons move around in the surfaces and edges of topological insulators, their spin axis aligns with their direction of flow. This effect (known as the quantum spin Hall state) means that electrons can’t easily reverse direction. In normal conductors when they hit an impurity they scatter and dissipate energy.
Although Stanene and superconductors can both exhibit zero resistance, Zhang emphasized that Stanene is not a superconductor. While the edges of Stanene act as a zero resistance path for electrons, they still encounter contact resistance at their junctions with normal conductors. In superconductors however, electrons travel in pairs, a phenomenon that eliminates contact resistance so that normal conductors effectively act like superconductors when in contact with a superconductor. [via]
Zero Resistance but not Superconducting? - [Link]
DM&P has been producing low-power, x86-based Vortex processors for the embedded market for over ten years. Now in a nod to the Arduino market they have released the 86Duino Zero, a low-cost Arduino Leonardo sized board powered by their latest 300 MHz SoC Vortex86EX Processor.
This is a fully static 32-bit x86 processor board compatible with Windows OS, Linux and most other popular 32-bit RTOS. It integrates a PCIE bus, DDR3, ROM controller, xISA, I2C, SPI, IPC (Internal Peripheral Controllers with DMA and interrupt timer/counter included). The 86Duino Zero’s ports include USB 2.0 host and device coastline ports, a 10/100 Ethernet port and a microSD slot on the bottom of the board. The Zero’s baseboard also provides a 7-12V power jack, a reset button and a PCIe expansion connector.
The Zero supplies 14 digital I/O pins, half of which can provide 32-bit resolution PWM outputs and six 11-bit analog input pins. Each standard I/O pin supplies 16 mA while the 3.3 V pins can supply up to 400 mA. Like the Intel Galileo development board announced several weeks ago the 86Duino Zero marries Intel architecture to the Arduino platform. Its $39 price tag makes it an attractive proposition. [via]
The 86Duino Zero Runs Linux on x86 - [Link]
Universal multimeter UT139C with a high resolution will be appreciated at development and everywhere, where you need to find out a situation in a given device accurately
Imagine a situation, when you need to check or set a voltage of 3.3V or 5V usual at digital electronics (AD converters reference,…). Or to measure the end of recharging of Li-ion/ Li-Pol batteries at 4.20V when it really matters on every miliVolt. In these cases, with usual multimeters you´ll face one cardinal fact – regarding that the most of them has a max. display reading of 1999, you´ll measure in hardly the first quarter of a range, thus with a significantly lower resolution. For example instead of desired 4.001 V (3 decimal positions), you´ll only see 4.00V. Naturally, we don´t always need such a high resolution but many times an improvement of resolution in one magnitude can provide us a worth information about a real situation in a measured circuit. In these situations it often doesn´t matter on the absolute accuracy that much, but right on a resolution, especially when comparing voltages in two points, increase/ decrease…
From this point of view is the novelty in our stock UT139C an excellent device providing besides a high resolution (5999) also another features worth to notice, for example: TRUE RMS measurement in a range of 45Hz-1kHz (to 400 Hz with VFC filter activated), measuring of high-capacity capacitors up to 99.9 mF (99 999 uF), measuring of duty cycle in a range of 0.1% – 99.9% and other. Not quite common is also measuring of uA and mA even in AC range. Function Rel is useful even at measuring of small capacitors, where it´s able to eliminate “offset” caused by a capacitance of testing leads.
A thermometer (K type) with arrange of -40 to 1000°C can also be useful at development. From some point of view it´s advantageous supplying by two AA cells, not by a classic 9V battery (AA cells have a better capacity/ price ratio).
UT139C is also able to serve as a non-contact AC voltage tester (NCV), indicating in 4 steps a proximity of >100VAC voltage. . Indication is by a red LED in the upper part of display, by a display (-,–,—,—-) and by a buzzer.
Further information will provide you the UT139C datasheet.
With the UT139C you´ll find out why 5999 is better than 1999 - [Link]
A small, simple AM receiver project. This AM receiver can pick up medium wave stations in your area
This circuit can use general purpose transistors, and in this example there are 3 BC109C transistors. In this schematic and BOM there is a 200uH inductor and a trimmer 150-500pF capacitor, though these parts can be salvaged from an old AM radio, to preserve the directional nature of a tuning coil, and an adjustment knob (plate capacitor) that work well for radio reception.
The 120k resistor is for regenerative feedback between the Q2 NPN transistor and the input to the tank circuit. The value of this resistor is important to the performance of the entire circuit. In fact, it may be better to replace the fixed value with a variable resistor paired with a fixed resistor to adjust the oscillation and sensitivity of the circuit. All the connections in this circuit should be short to minimize interference.
Performance of the circuit will vary depending on stray capacitance in your layout, the inductor winding/core/length, etc. Changing values of some of the capacitors, or adding them, as well as a potentiometer in the feedback loop can help with the performance of the receiver. With such a small circuit that is affected so much by its construction and its environment, a lot of hand tuning and experimentation will be fun, instructive, and possibly necessary to make it work best.
Simple AM Receiver Project - [Link]
by Publitek European Editors:
Monitoring is the key to unlocking the energy production of the solar cell. It is easy to lose efficiency through the use of circuit architectures that assume constant energy production when the solar environment is constantly changing.
The change in current-voltage properties as a solar module heats up or receives more light can be an important source of efficiency losses in solar arrays. If the inverter that generates grid-compatible electricity is not tuned to the output voltage and current conditions, it will waste more of the electricity than it should. In response, electronics companies have produced ICs that perform the maximum power-point tracking (MPPT) needed to optimize energy conversion as well as bypass electronics to prevent temporarily unproductive modules from disrupting the output of active cells.
Maximizing the Output from Solar Modules - [Link]
Tutorial on how to make your own custom LCD at home!
DIY Custom LCD - [Link]
The LT8614 is a 4A, 42V input capable synchronous step-down switching regulator. A unique Silent Switcher architecture reduces EMI/EMC emissions by more than 20dB, well below the CISPR 25 Class 5 limit. Even with switching frequencies in excess of 2MHz, synchronous rectification delivers efficiency as high as 96% while Burst Mode operation keeps quiescent current under 2.5μA in no-load standby conditions. Its 3.4V to 42V input voltage range makes it ideal for automotive and industrial applications.
LT8614 – 42V, 4A Synchronous Step-Down Silent Switcher with 2.5μA Quiescent Current - [Link]
New 2mm safety system Hirschmann for measuring and testing will serve even in tight spaces, on densily populated PCBs and similar.
It´s not that far, what we introduced to you a wide portfolio of a measuring and testing equipment from SKS-Hirschmann in the article SKS – measuring and testing with pleasure. It can be said, that almost everyone, who´ll try testing probes or clamps from SKS, will quickly favor them and they differ from many „no-name“ products by a precise, sufficiently rigid construction.This time, the company SKS comes with a novelty in a form of a 2mm safety system, which despite small dimensions meets specification for CATIII – 1000V. As this system for 2mm banana plugs is significantly smaller than 4mm system, it enables a comfortable and effective measurement even in tight conditions, at smaller components, …
Naturally, this system can be convenient not only because of 1000V max. voltage but also thanks to smaller dimensions of banana plugs and a whole set of accessories. That´s why we´ll appreciate it at measurement in all applications where there´s “no space left”.
New safety system we keep as items upon order, but probably we´ll soon incorporate it to standard stock items.
Even a miniature testing clamp can handle 1000V - [Link]
Andrew Rossignol has written an article detailing his YALEDD – 16×16 LED display project:
The class was instructed to choose a simple circuit such as an LED flasher or a simple sequential state machine composed of discrete logic, capture the schematic, layout the PCB and have it made by the end of the term. I decided that it would be boring to design a simple state machine. I also thought it might be pretty cool to have an electronic gizmo of my own design to show off on my desk at work.
YALEDD! 16×16 LED display - [Link]