Wednesday, February 24, 2016

The Oscilloscope Artist

The Oscilloscope Artist originally appeared in the November, 1975 issue of Popular Electronics. It creates all sorts of fascinating moving geometric patterns on an oscilloscope screen.

All you need is a low bandwidth 'scope with horizontal and vertical (XY) inputs.

Updates (2018/02/16): David Dixon spotted a really stupid typo in the original pdf file that was shared below. This has been fixed and the latest version is now 1.2.1. All other (unattributed) copies floating around the Internet are of the earlier, incorrect version.

(2020/04/10): A new PC board layout using TL074 quad op-amps is now available as well as etched boards! Message me.

A reconstruction of the complete article is in a pdf file. All of the original parts are still available!

The original block diagram is a bit confusing so I redrew it. Oscillators A & D create a Lissajous figure baseline from triangle/square waves. Oscillators B & C are multiplied and summed with A & B.

To make things interesting, C is 90° out of phase between the multipliers. All the oscillators are sync'd to A, which is ~60Hz. All of this produces complex patterns which move and shift.

I've also used it with a laser projection system with X and Y galvos and it works although the corners aren't too sharp.