New South Wales I

Видеоролик, демонстрирующий работу прибора



George Katz of Balgowlah Boys high in Sydney presented a solid state oscilloscope. He says "probably the best advantage is its very small size and the fact that it can run off the power supply of the circuit being tested. Although it has a low frequency range, it can still be used for most circuits. Its poor resolution will still allow for most waveforms to be visualized."

This was pretty much the judges' own assesment of Katz's project. It uses a matrix of 100 LED's for a display, and does suffer from being slow and having rather poor resolution. Still we could display a sine wave running at 500Hz without trouble, that that's not all that dissimilar to commercial solid state osscilloscopes.

The circuit displays an understanding of the mechanics of displaying an analogue waveform. The timebase is simply a 555 generating a horizontal sweep, while the vertical amplifier is 3914 with a trimpot on the front. It's extremely simple, but it works.

The LEDs are multiplexed by a 4017 driven by the timebase. This arrangement reduces the current requirements considerably, no mean consideration when operating from the power supply of the device under test.

With a device like this, making the unit as small as possible is obviously a consideration. Katz decided to make his own box out of perspex so that he could make it just as big as the circuit board, and no bigger. He was also able to give the thing a fancy shape rather like a bought one.

On the basis that this project had the highest combination of imagination, design ingenuity, construction and documentation, we made it the national winner.