Rugged Battery Charger

Using some recycled halogen lamp transformers, this tough battery charger is simple to use and sturdily built in a steel case. Protected with thermal cutout. A useful piece of kit made from throw-away items.

 

 

CLASSiC-D ±35V DC-DC Converter

This design works with our CLASSiC-D amplifier (Nov. and Dec 2013), offering an efficient way to run the module from a 12V battery. This switched-mode design turns your amp into a compact powerhouse! Optimised to offer some 100W into 4 ohms and 60W into 8 ohms from a 12V supply.

 

Digital Multimeter Auto Power Down

 

Designed as an add-on for cheap and cheerful imported DMMs, this useful accessory wires straight into the DMM and turns it off automatically after pressing a button and a fixed period elapses.

 

Saves costly battery replacement and helps keep your DMM ready for use. Very simple to build and could pay for itself many times over.

 

Arduino Internet Relay Control

Switching devices on and off via the Internet has generally been a complex and expensive task due to the hardware and skills needed – but this article highlights a method based on open-source Arduino-based hardware and utilises an Arduino Uno-style board and Ethernet shield.

 

Teach-In 2014 Raspberry Pi (Part 8)

 

The latest part of our marathon Raspberry Pi tutorial series describes stepper motor control techniques and introduces one of the Pi’s most popular accessories, the Pi Camera.

 

PIC n MIX - Development Board Programming

Our in-house PICmicro expert explains how to construct a microcontroller program and debug the application if things go wrong. Introduction to 'C' language.

 

Also in this issue:

• Circuit Surgery – LED constant-current drives outlined and simulated
• Net Work – testing Philips Hue network-controlled multicolour wi-fi LED bulbs
• Techno Talk on emerging wireless charging standards
• Practically Speaking – more practical tips for the constructor
• Max’s Cool Beans Blog – Max can not only spell ‘Pedagogical and Phantasmagorical Inamorata Prognostication Engine’ but he’s building one as well!

 

You can order a printed copy of EPE for delivery to your door (worldwide), or try the PDF Version (needs Adobe Reader for Windows), or the Pocketmags for your mobile device. Subscribe now!

 

Source code file 0514.zip (PIC n MIX, Teach-In 8)

 

PCB artwork

 

As from July 2013 issue PCB artwork is available free to subscribers only.

 

Non-subscribers may purchase artwork files for a nominal sum. Please contact our Orders Dept for information or to place an order.

 

EPE Printed Circuit Boards

 

We can supply ready-made printed circuit boards (8-digit order codes) to the original design specification via mail order or from our Online Shop.