22 July 2010

Last month, we introduced our new Dual Tracking ±19V Power Supply and explained how it works. This month, we show you how to build the PC boards, install them in a case, wire it up and get it going. Both the mains-powered and plugpack-powered versions are covered.

18 July 2010

No, this is not some kind of fancy digital volume control for hifi systems. Instead, it's a low-cost digital programmable voltage divider. It's used to provide an accurate adjustable output from a precision voltage reference for meter calibration and other tasks.

10 July 2010

With the abundance of microprocessor/microcontroller variations available these days it is no small wonder that many of the designs produced by electronic enthusiasts use one type or another of these components. And most commercial equipment these days has a micro controlling it. But how do you get from an idea to a working design?

04 July 2010

Does your computer make more noise than it should? It's probably mostly fan noise! Slowing the fans down will reduce the noise but if you go too far, you could end up with fricassee of CPU!

23 June 2010

Last month we described the operation of our new off-grid lighting system, featuring free power courtesy of the sun! Now we move on to the fun part: building it!

21 June 2010

Think all your double-insulated power tools are safe, just because they are double insulated? As many have found to their ultimate cost, wear and tear on tools can mean that they become decidedly unsafe. Here's a meter that will give you back your peace-of-mind – on tools and many other electrical and electronic devices.

13 June 2010

This linear bench supply can deliver up to 1.6A from positive and negative outputs with a range of ±0-19V. It has adjustable current limiting for both outputs and can display the voltage or current reading for either rail. If powered from an AC plugpack, no mains wiring is required, although less current is available. It also has a 5V 750mA output for powering digital logic ICs and microcontrollers.

09 June 2010

This Air Quality Monitor indicates carbon dioxide (CO2) and carbon monoxide (CO) levels on a dual bargraph and sounds an alarm when either level reaches a preset concentration. You should use it if you have an unflued heater in your home, boat, caravan or any indoor space.

22 May 2010

In the March and April 2010 issues, we described the design and construction of our new Digital Audio Signal Generator. The final article this month has the driving instructions.

18 May 2010

Looking for an efficient USB charger that can operate from a 12V car battery? This unit functions at up to 89% efficiency and can charge USB devices at currents up to 525mA. Best of all, it won’t flatten the battery if it's left permanently connected, as long as you remember to unplug the USB device.