Simple Stuff

Electronic Patterns

Children, particularly, have a natural fascination with patterns. For some this develops into a greater passion, whilst others relish chaos and lack of disciplined order. The fact remains that most people can rapidly detect the existence of a pattern and appreciate the sense of order or repetition that it can offer.

Computers on the other hand can use vast amounts of processing power to determine whether or not a given image contains a pattern. There are programs to sort things like number patterns but these are already partially decoded systems.

The relevance to electronics is quickly established by looking at the requirements for some simple examples. In various forms of equipment there is a need for two measurement channels to operate with identical performance. Stereo (2 channel) audio relies heavily in the fact that the two channels have identical behaviour and response. Even the everyday USB connection (USB 2.0) has stringent demands for the data pair to be "balanced".

In a multi-channel measurement system it may be possible to "cut and paste" some elements of the design. The copied elements are identical replications of the original pattern. Design software even simplifies the time and effort for this kind of recurrence. However, there are many situations where the pattern needs to be handed, left and right, up or down not just two of the same. This is where humans start to have the lead.

It can be laborious or even obsessive to achieve a well structured, handed design. The results of such endeavour are intuitive and readily appreciated. Perhaps, more important than all of these, is the end performance which is the final proof.

Balanced connections are another instance where even the name carries a suggestion of pattern. Such connections require that the signal in each wire is of the same size but opposite in terms of direction. (One is up-side-down if you like).

The path and circuit followed by each half of a balanced pair must be as identical as possible. In this way any interference or degradation of the signal is equally applied to both halves. The end point of the signal delivery subtracts one half from the other. Mathematicians and engineers will be able to tell you that this results in twice the desired signal and (only in theory) a total loss of interference.

Patterns are not just child's play but an important consideration in today's high performance electronics. There are many considerations in any design but patterns should be visible even to the relatively untrained eye. When you see it, you know that it is there and you can have confidence that the engineer/artist has done his/her job well.

This image of a car amplifier contains multiple patterns. The top half of the board is four channels, handed left and right. The lower half of the board also caries two pairs of channels (4 total) with similar requirements between the two pairs. The patterns extend down to track placement too. - Click image for lager pictue.