by Jessica MacNeil @ edn.com:
What began as research to improve telephone service became one of the most important inventions in electronics history.
In 1945, AT&T’s research division, Bell Labs, began working on technology to replace vacuum tubes and make long-distance telephone service more reliable. William Shockley organized a solid-state physics group to research semiconductor replacements for vacuum tubes and electromechanical switches.
1st successful test of the transistor, December 16, 1947 - [Link]
Double the iPhone, double the teardown! With the iPhone 6 Plus laid out for inspection, we turn our attention to the smaller iPhone 6—though at 4.7″, it’s still a giant among iPhones. What was so big that Apple couldn’t fit it into the familiar form factor? Let’s shake it out onto the teardown table and find out!
iPhone 6 Teardown - [Link]
Lukas of Soldernerd built a DIY Arduino-based inductance meter:
I’ve just finished a little Arduino project. It’s a shield for the Arduino Uno that lets you measure inductance. This is a functionality that I found missing in just about any digital multi meter. Yes, there are specialized LCR meters that let you measure inductance but they typically won’t measure voltages or currents. So I had to build my inductance meter myself.
Arduino-based inductance meter - [Link]
by Peter Demchenko @ edn.com:
The purpose of this Design Idea was to improve reliability, add new features, and replace a latching power switch with a momentary one.
The features are:
The switch has foolproof protection against too frequent switching, which can be harmful for many applications.
It can handle significant power because manual control and switching are separated.
If an unexpected power outage occurs, the switch disconnects and remains off after power returns.
A unit can switch itself off.
Momentary switch controls mains with latch-on and remote shutdown - [Link]
This is a quick project for a timer. Recently I finished my UV light exposure box and thought that it will be convenient to have a build in timer to switch off the light after preset time. So I had a PIC16F628A lying around and after searching the web I found a Brazilian site (I think?) with tons of interesting projects with microcontrolers. This project is based on one of them.
The schematic uses the internal oscillator of the microcontroller which is enough accurate for my purposes, but as the pins 15 and 16 are left unoccupied, there can be connected external quartz resonator with better accuracy. As I said, this project is based on an existing project, but actually my schematic is quite different and the code was almost completely rewritten. My programming abilities are little rusty, but I think the final result is quite good.
Simple timer with PIC16F628A - [Link]
by Solarcycle @ instructables.com:
Power Stacker is a portable, modular, USB rechargeable lithium-ion battery pack. Stack them together for power hungry projects or separate them for smaller projects with this modular system. The Gerber, BOM, and .STL files are available below.
Power Stacker does what other USB rechargeable batteries have failed to do, and that’s the ability to combine together for increased battery capacity or separate in to many small batteries for smaller projects. You can literally use the same Power Stacker batteries for many years across many applications!
Stackable USB Rechargeable Battery System - [Link]
by Susan Nordyk @ edn.com:
Leveraging Linear Technology’s Silent Switcher architecture and spread- spectrum frequency modulation, the LT8640 synchronous step-down switching regulator reduces EMI/EMC emissions by more than 25 dB—even with switching frequencies in excess of 2 MHz—enabling the part to easily pass automotive CISPR25, Class 5 peak limits. Synchronous rectification achieves efficiency as high as 95% with a switching frequency of 2 MHz, while the part’s 3.4-V to 42-V input range makes it useful for both automotive and industrial applications.
Step-down switching regulator minimizes EMI/EMC - [Link]
by Susan Nordyk @ edn.com:
International Rectifier’s IRFH4257D is a 25-V dual N-channel power MOSFET housed in a 4×5-mm PQFN power-block package aimed at 12-V input DC/DC synchronous buck applications, such as telecom equipment, servers, graphic cards, and computers. With this latest power-block addition, designers now have the option of choosing a 4×5-mm or 5×6-mm PQFN to suit their design requirements.
Dual MOSFET squeezes into PQFN package - [Link]
by dany @ elecfreaks.com:
Smart RGB LED Strip is based on the development of our BLEduino, using the Bluetooth 4.0, and the sample code written by EF men, by mobile phone APP, to control the switch of RGB LED strip, and the RGB LED color changing. The main principle is that using BLEduino mega328P chip three PWM pins respectively to control the RGB LED strip of R G B three colors. When the phone APP and BLEduino bluetooth pairing connection succeed, phone APP can control mega328P chip three PWM pins output value, then control the the color of the RGB LED strip
Smart RGB Strip with BLEduino DIY Guide - [Link]