20 January 2009

The PC board used for the USB Sensing Power Switch can also be used to build a remote mains relay. This can be used for switching mains power to lights or appliances using a remote switch (or relay) linked by low-voltage wiring. It can also be used for controlling security lights from the relay contacts on a PIR sensor.

15 January 2009

SatNav (GPS) units were one of the "hot" items at Christmas time. Most were the low-cost, low-featured variety. But we wanted to see what was offered in the top-of-the-range models and Navman came to the party with their just-released "Platinum" S300t. About the only thing it doesn't have is the kitchen sink. Oh, did I miss that?

13 January 2009

Do you have to manually switch your PC's peripherals on (and later off again) each time you boot your PC? If so, this project will make life a lot easier. It monitors your PC's USB port and automatically turns all that other gear on and off as required.

11 January 2009

08 January 2009

No doubt most readers will have seen the TV commercials for the current model Honda V6 Accord. The commercial shows a graphic demonstration of the engine's three modes whereby it can run on three, four or six cylinders. But while groups of musicians playing kettledrums might be spectacular, it does not give a clue as to how it's done.

07 January 2009

Lamenting the passing of local AM radio? Desert island or outback mining camp based? Unable to clamber up on the roof for a long wire aerial anymore? Here's a simple medium wave tunable loop that, even indoors, will bring signals out of thin air!

05 January 2009

Interesting circuit ideas which we have checked but not built and tested. Contributions from readers are welcome and will be paid for at standard rates.

20 December 2008

This project started out as a digital dashboard display but has grown and can be used in any measurement or data logging application where you have 9-12V DC available. It can monitor up to six signals and display up to 10 computed values in a scrolling or static readout on a 7 x 15 dot matrix LED display.

17 December 2008

This Simple Voltage Switch can be used anywhere you want a relay to switch when a voltage reaches a preset level. It has lots of applications in cars but can be used in any application where you have 12V DC available. Having switched the relay on, it will then switch if off as the voltage being monitored drops below the preset level.

16 December 2008

There is upheaval in the movie industry. More feature films are being shot with digital cameras and successfully transferred to 35mm film release prints with advanced technology. Surprisingly, film is still hanging in as a capture medium, due mainly to the pressure from cinematographers who claim that everyone wants that 'film look', while few set out to achieve that 'video look' in the cinema. Coming up fast on the inside is the 'digital look', as increasing numbers of cinemas around the world begin to install digital projection into their bio-boxes. Barrie Smith takes a look into the popcorn and choc-top world of the digital cinema revolution.