by Lee Goldberg @ edn.com:
The CircuitMaker PCB design tool could be thought of as the electronics enthusiast’s equivalent of Picassa, the free alternative to Photoshop – except that it’s a got a much more refined interface which makes it easy use. The program’s 3D modeling capabilities (more about that later) and other advanced features will help designers deal better with the “lumpy” nature of LED lighting products, or any other design project which involves large, irregular components. But that’s only half of the story. The software’s creators have also taken an interesting approach to solving several important technical and economic issues which have arisen with the Maker Economy by borrowing a few lessons from the movement’s own playbook.
Free PCB design tool includes 3D modeling, crowd-sourced parts database - [Link]
We are building another enjoyable weekend DIY project. This is an audio power amplifier based on LM1876 which can deliver up to 20W per channel into 4 or 8 ohm load and guarantees less than 0.1% THD + N (Total Harmonic Distortion + Noise).
The amplifier is powered by -15 0 15 VAC symmetrical supply. The full bridge diode rectifier and the smoothing capacitors convert the AC input to ±21 VDC which is used to power LM1876. The inductors on the AC input line reduces the noise arising from the mains line.
DIY LM1876 Dual 20W Audio Power Amplifier - [Link]
by Darren Quick @ gizmag.com:
There have been numerous cases of lithium-ion batteries catching fire in everything from mobile phones and laptops to cars and airplanes. While the odds of this occurring are low, the fact that hundreds of millions of lithium-ion batteries are produced and sold every year means the risk is still very real. Researchers at Stanford University have now developed a “smart” lithium-ion battery that would provide users with a warning if it is overheating and likely to burst into flames.
“Smart” lithium-ion battery would warn users if it is going to ignite - [Link]
80 dB acoustic signal at only 3V power supply and a really miniature size place this new component into a top class.
Belgian company Sonitron and its top-level products ar probably familiar to you from our articles and from our offer in this segment. We continue in increasing of standard stock types and this time we have here an extraordinary interesting type – SMA-13LV, interesting mainly for low-voltage applications. Series of buzzers marked as “SMA” is known by its variousness, as we find here types with loudness of 75-98 dB, THT and SMT vesions, and versions with a stable, as well as intermittent signal. Various izes from 13 to 30 mm with a pitch of 7.5 to 20.32 mm enable to select the right type for a given application. In general, bigger types provide a more loud signal, but it depends on a concrete type. This series is suitable for general use – everywhere, where a reliable buzzer is necessary, including industrial conditions.
For a succesfull use, it´s only necessary to connect a suitable supply voltage – usually in extremely wide range (for example 1.5-15V). Usually, on the upper end of a supply voltage range we get the highest loudness and at lower voltages we receive a higher lifetime.
Very similar is also the SMAT series (transducers), which in contrast to the SMA series doesn´t contain a driver, that´s why it needs an extenal electronics.
For really tough conditions, the Sonitron SAP. series is suitable. These are buzzers for various usage in traffic, for example as a reverse movement indicator (danger of close approximation). They excell in extreme rigidity, what make them widely used even in avionics, miltary and trucks. SAP series has a specifi usage, that´s why we keep these types as items upúon request.
Another novelties in our standard stock offer can be found below this article. Detailed information can be found in datasheets at particular types and in the new Sonitron 2014 catalogue.
Piezo buzzer Sonitron SMA-13LV deploys maximum from a minimum - [Link]
This article introduces high quality digitally controlled 2.1 channel analog audio power amplifier system. This project is mainly based on TDA7377 AF power amplifier and PIC18F452 8bit microcontroller. Basic technical features of this receiver are covered in table1.
This unit is specifically design to work with PC sound cards, radio receivers and CD/DVD/Blue-Ray players.
Digitally Controlled 2.1 Channel Analog Audio Power Amplifier - [Link]
by Victor8o5 @ instructables.com:
WARNING: Before you start making anything please take a moment and read this:
This circuit is intended to be used for educational and experimental purposes (electrostatic experiences, franklin bell experiment, plasma generation, gas ionization, electronic igniter, testing of insulating materials…) this circuit should not leave the lab or your house, and it shouldn’t be used to harm to anybody, human or animal.
Do not attempt to replicate this circuit if you aren’t familiar with high voltages or intermediate electronics, high voltages are very dangerous.
High voltages can disrupt electronic equipment, so don’t keep phones, pacemakers or other sensible electronic devices near the supply.
I’m not responsible for the use given to this device and I’ve made all what it’s on my hands to include safety related information, and safety implementations to the circuit.
Follow the general security measures when dealing with high voltages, here you have a nice safety guide, please read it carefully before you continue.
Mini high voltage supply - [Link]
by Jordan Dimitrov @ edn.com:
While most carbon dioxide sensors use IR technology, electrochemical sensors are a serious competitor because of their high sensitivity, wide measurement range, and low price. As a rule, electrochemical sensors connect to a microcontroller through a buffer amplifier with an extremely low bias current (<1pA). The micro is needed to linearize the logarithmic response of the sensor. A good example of this approach is the SEN-000007 module from Sandbox Electronics, which uses an MG-811 CO2 sensor from Hanwei Electronics. Reference 1 reveals the circuits and the code, but does not specify accuracy.
Antilog converter linearizes carbon dioxide sensor - [Link]
Before I began the installation of my Yaesu FT-8800 in my car I knew I wanted automatic power ON / OFF. This is a feature that I have always felt was lacking in my other mobile rigs as I am forever leaving my ham radio on long after I have departed the car.
Let’s start with an action packed video of the finished product, then we can talk about how we got there.
Mobile Radio Power Controller ( MRPC ) - [Link]
by mlerman @ instructables.com:
This is the second version of my E260 modification. It uses an ATtiny13 MCU to control the timing of the printer and make it possible to print double sided PCBs at home.
As an electronic hobbyist and inventor I often need to make printed circuit boards (PCBs) in single or small quantities. Usually these are relatively simple circuits, an MCU, some input conditioning circuitry, some output circuitry, and usually they are single sided or perhaps double sided, with just a few vias. And usually I want them right now!
Toner Transfer (TT) has become the method of choice for most hobbyists. A laser printer is used to print an image of the PCB on special “transfer paper” which is then placed on the bare copperclad board and either ironed on or run through a modified laminator to transfer the image to the copper. When the PCB is etched, the toner acts as a resist, preserving the copper below it while the rest of the copper surface is etched away.
Modification of the Lexmark E260 for Direct Laser Printing of Printed Circuit Boards - [Link]