February 2013 Issue
A summary of this month's contents.
Semtest (Part 1)
Check your collection of discrete semiconductors with this easy to build test unit.
This PICMicro-based design will test a wide range of active components, including LEDs, diodes, BJTs, MOSFETs, SCRs and more. You can even run tests on IGBTs and triacs. Menu-driven LCD display, multi-configuration ZIF connections connect to all common device pin-out styles.
Hifi Stereo Crystal DAC upgrade
This upgrade DAC board can be substituted for the original board used in our hi-fi Stereo DAC Project (Sept. – Nov 11 EPE) without any major changes.
It replaces the Burr-Brown DSD1796 DAC i.c. with the high-end Cirrus Crystal CS4398. Its harmonic and intermodulation distortion figures are significantly lower than before – find out if you can tell the difference!
10W LED Floodlight
Halogen floodlamps uses power-hungry unreliable incandescent bulbs and a typical 150W type might output about 15 lumens per watt when new. (Output falls with age.)
We offer this alternative compact floodlight design based around a high-power LED module that puts some old incandescent lamps in the shade!
It’s an efficient solid-state design with high-efficiency 3x3 10W LED module that offers a more modest 72 lumens per watt – that’s half the light output of a 150W halogen, but it’s five times more efficient. Full details are included, also available in kit form from www.oatleyelectronics.com
Fancy some unobtrusive loudspeakers in your house?
The novel approach explained in this article is to build the speakers into the walls and floors – perfect if you’re renovating a property. The principles of embedding a ported speaker system are fully illustrated in this feature.
Universal USB Data Logger – Part 3
The third and final part explains how to use the accompanying Windows host software.
Design and build circuit projects dedicated to newcomers and younger students following courses in schools and colleges. This month our tutors delve into the world of digital circuitry, helped by Circuit Wizard simulation and measurement software to investigate basic logic gates and signals.
Also in this issue:
- Raspberry Pi – our in-house Pi expert explores some approaches for developing software on the Raspberry Pi.
- Technotalk – looking into the future - stand by for super capacitors.
- Max’s Cool Beans – Max contrasts his evolution in mainframe computing against what technology has to offer us today.
- PIC n MIX – lifting the lid on efficient power management and how to reduce the power consumption of many PICmicro projects.
- Circuit Surgery – our surgeon digs into diodes and explains all the basics of power rectification and voltage-doubling circuits. Ideal for beginners and a worthwhile refresher for old hands, too.
- Interface – for PC users. Practical examples of fluid level sensing and person-detection using PIRs
- Net Work – the Internet column. Broadband gone down? This month our Internet expert explains how to couple a typical Windows smartphone to a Windows 7 PC to use the phone’s GPRS data service instead. Bluetooth and USB dongles are included.
Source code 0213.zip
PCB files pcb0213.zip
PCB artwork for the 10W LED Floodlight is not available for download.
Please Take Note
Universal USB Data Logger (Part 3)
The PDF 'USB Data Logger User Manual' referred to on P. 45 is in actual fact the file help.pdf already included in the source code download in December 2012. We apologise for any confusion caused.