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]
A Flexible Oven Controller controlled via touch screen or through USB. Draw and download your own profiles using free Profile Creator.
Zallus Oven Controller - [Link]
Arduino WebRadio player is an inexpensive WebRadio player that can plays internet audio streams up to 64-kbps and is based on mp3, aac and wma audio formats.
The main components are:
- Arduino Pro mini board
- ENC28J60 ethernet module
- VS1053B mp3, aac, wma decoder
- 84×48 dot matrix LCD module (Nokia 5110)
Arduino WebRadio player - [Link]
You are planning to use Arduino in your project but you need some kind of remote control functionality. A standalone Arduino won’t provide what you need but this DIY shield may be a good solution for you. It includes a 433.92Mhz RF receiver which lets you send commands to Arduino wirelessly and four SPDT relays which can be used for switching purposes.
Each relay is capable of switching up to 10A @ 250VAC so they can be used to control mains powered devices. There are four LEDS indicating the status of the relays. The terminal blocks on the shield lets you easily connect the devices you will control.
The RF receiver is a module that can be found in the market easily. It is directly soldered to the shield and runs at 4800bps. The board has an antenna input which lets you solder your custom antenna to increase the wireless range.
DIY 433MHz RF Receiver and 4 x SPDT Relay Shield - [Link]
RFID keyboard emulators are able to significantly simplify tracking of goods.
“Replacement” of a keyboard in a form of an RFID module connected to a USB port works very simply – UID of every tag, which will appear in its range will send to a computer – the same way as if we typed it in by a keyboard. SL040A also enables to choose, whether we want the reader to send only data, or also a „CR“ character after every UID (as if an Enter key was hit). It means, that if we already have a software to type in open (for example Excel), the reader itself will fill the cell with data and move the cursor to another cell. SL040A is even able to read data (not only UID) from Mifare tags.
SL040A is also interesting by one feature – on a request from our company SOS electronic, the producer started to produce also the black version SL040A black. Thanks to the above-standard close relationship with the producers, we´re able to supply you even various special customized versions.
Detailed information will provide you the SL040A user manual.
SL040A will load it to you directly into a table sheet - [Link]
Transformer soldering tool Toolcraft SP200 is a useful complement even if you already have a quality soldering station.
In praxis, it´s possible to heard various opinions on “transformer soldering tools”. Usually this is the first type of a soldering tool with which a young electro-technician begins. It´s small, a tip heats up quickly, doesn´t take a lot of space, it´s easily transportable and last but not least it´s also price – affordable.
From the point of view of a professional working with SMT components it can be reproached, that it´s not suitable for SMT components of 0603/ 0402 and similar, it creates a pulse at switching on (weak ESD safety) and it has no soldering tip temperature control.
Despite this, many of us are glad to return to it sometimes, because it´s simply “handy” :-). It provides a magic of an easy application of a solder and a colophony in a single step by a classic way, when we take a bit of a solder on a hot tip and after switching off (during cooling down) we immerse a tip into a colophony. This way we get prepared one “soldering dose” on a tip, suitable for soldering of poorly solderable joints (depending on features of a solder and colophony). At the same time, it´s very convenient in case we need to have one hand free for holding a soldered component, wire, …
Even a small stability of a tip temperature can be bypassed by experience (not too long heating) and the risk of sensitive components damage can be considerably decreased if we always switch on a soldering tool before touching a given component, and similarly – switch off after taking away a tip from a component.
It can be said, that a quality soldering station is irreplaceable for a serious work, but there are many cases, where a classic pistol-type soldering tool alike. In respect to an extraordinary affordable price level of the Toolcraft SP200 and also other in our offer (10-20 Eur), this tool is a suitable complementary tool for every electro workshop and for a work in places, where a transport of a bulky soldering station might be quite impractical.
Toolcraft SP200 has a more robust tip, suitable also for bigger joints. On the opposite side, soldering tools of the series ETP use classic relatively thin tips usable even for small soldering tools.
Think about a soldering tool for every occasion - [Link]